In The Logic of Scientific Discovery, sec. 85, Popper writes:

Science is not a system of certain, or well-established, statements; nor is it a system which steadily advances towards a state of finality. Our science is not knowledge (epistēmē): it can never claim to have attained truth, or even a substitute for it, such as probability.

Yet science has more than mere biological survival value. It is not only a useful instrument. Although it can attain neither truth nor probability, the striving for knowledge and the search for truth are still the strongest motives of scientific discovery.

What does Popper mean when he denies science is "knowledge (epistēmē)"? He explains (sec. 85):

The old scientific ideal of epistēmē—of absolutely certain, demonstrable knowledge—has proved to be an idol. The demand for scientific objectivity makes it inevitable that every scientific statement must remain tentative for ever.

His point here is fallibility. There's no way to ever prove an idea with finality so that there's no possibility of it ever being overthrown or improved in the future. There's no way to be 100% certain that a new criticism won't be invented later.

People consider Popper a skeptic because they see the options as infallibilism or skepticism. Popper does deny infallibilist conceptions of knowledge, but disagrees that infallibilism is a requirement of genuine knowledge.

In the first quote, Popper uses the word "knowledge" in two different senses, which is confusing. The first use is qualified as "epistēmē" and refers to view that we must find a way around fallibility or we don't have any knowledge. The second use, in "striving for knowledge", means good ideas (useful ideas, ideas which solve problems) as opposed to random, arbitrary or worthless ideas. The view that we have no way to judge some ideas as better than others is the skeptical position; in contrast, Popper says we can use criticism to differentiate ideas.

I'll now discuss individual pieces of the first quote.

[science] can never claim to have attained truth

Popper means that even if we had an idea with no errors, we have no means to absolutely prove it has no errors and then claim there are none. There are no methods which guarantee the elimination of all errors from any set of ideas.

An idea with no errors can be called a final or perfect truth. It can't be refuted. It also can't be improved. It's an end of progress. Human knowledge, by contrast, is an infinite journey in which we make progress but don't reach a final end point at which thinking stops.

Could there be unbounded progress while some ideas, e.g. 2+2=4, are never revisited? Yes but there's nothing to gain by being dogmatic, and there're no arguments which yield exceptions to fallibility. Just accept all ideas are potentially open to criticism, and then focus your research on areas you consider promising or find problematic. And if someone has a surprising insight contradicting something you were confident of, refute it rather than dismissing it.

[science] can attain neither truth nor probability

Regarding probability: There's no way to measure how close to the (perfect) truth an idea is, how much error it contains, or how likely it is to be (perfectly) true. The method of judging ideas by (primarily informal) critical arguments doesn't allow for establishing ideas as probable, and the alternative epistemological methods don't work (Popper has criticisms of them, including on logical grounds).

Also, probability applies to physical events (e.g. probability of a die rolling a 6), not to ideas. An idea either is (perfectly) true or it isn't. Probability of ideas is a metaphor for positive support or justification. I've addressed that issue under the heading: gradations of certainty.

Science is not a system of certain, or well-established, statements

What's good about scientific statements if they aren't well-established or certain? They aren't refuted. We've looked, but haven't found any errors in them. That's better than ideas which are refuted. I shouldn't accept or act on ideas when I'm aware of (relevant) errors in them.

My judgements are capable of being mistaken in general. But that isn't a criticism of any particular judgement. Ideas should be rejected due to critical arguments, not due to fallibility itself.

striving for knowledge and the search for truth

The human capacity for error ruins some projects (e.g. attaining absolute certainty, attaining epistēmē). But it doesn't prevent us from creating a succession of better and better ideas by finding and fixing some of our errors.

Popper and After: Four Modern Irrationalists, by David Stove criticizes Karl Popper's philosophy of knowledge.

But Stove's criticism doesn't focus on epistemology.

And Stove writes insults and other unserious statements. These are frequent and severe enough to stand out compared to other similar books. I give examples.

The book's organization is problematic as a criticism of Popper because it criticizes four authors at once. It only focuses on Popper for a few paragraphs at a time. It doesn't lay out Popper's position in detail with quotes and explanations of what problems Popper is trying to solve and how his ideas solve them.

First I discuss the book's approach and style. Then I address what I've identified as Stove's most important criticisms of Popperian philosophy.

My basic conclusion is that Stove doesn't understand Popper. His main criticisms amount to, "I don't understand it." Popper contradicts established philosophy ideas and some common sense; Stove doesn't know why and responds with ridicule. Stove is unable to present Popper's main ideas correctly (and doesn't really try, preferring instead to jump into details). And without a big-picture understanding of Popper, Stove doesn't know what to make of various detail statements.

Stove's Focus

Part 2, Ch. 3 begins:

Popper, Kuhn, Lakatos and Feyerabend have succeeded in making irrationalist philosophy of science acceptable to many readers who would reject it out of hand if it were presented to them without equivocation and consistently. It was thus that the question arose to which the first Part of this book was addressed: namely, how did they achieve this? My answer was, that they did so principally by means of two literary devices discussed in Part One. The question to which the present Part of this book is addressed is: how was irrationalist philosophy of science made acceptable to these authors themselves?

Stove says the first part discusses how Popper achieved influence. How did Popper convince readers? What literary devices did Popper use to fool people? And part two (of two) discusses the psychological issue of how Popper made irrationalism acceptable to himself.

By Stove's own account, he's not focusing on debating philosophy points. He does include epistemology arguments, but they aren't primary.

The problem Stove is trying to solve plays a major role in his thinking (as Popper would have said). And it's the wrong problem because it assumes Popper is an irrationalist and then analyzes implications, rather than focusing on analyzing epistemology. If Popper's philosophy is true, Stove's main topics don't matter.

Ridicule

Ch. 2:

It is just as well that Popper introduced this [methodological] rule. Otherwise we might have gone on indefinitely just neglecting extreme probabilities in our old bad way: that is, without his permission.

This is unserious and insulting. Popper's purpose was to discuss how to think well, not to give orders or permission.

To readers in whom the critical faculty is not entirely extinct, the episode has afforded a certain amount of hilarity.

This is mean.

I point out more examples of Stove's style as they come up.

Neutralizing Success Words

Ch. 1 discusses neutralizing success words. A success word like "knowledge" or "proof" implies an accomplishment. Compare "refuted" (a successful argument) to "denied" or "contradicted" (doesn't imply the denial has merit). Neutralizing knowledge yields idea – knowledge means a good idea, whereas an idea could be good or bad. Neutralizing proof yields argument – a proof is a type of successful argument, whereas a mere argument may not succeed.

Stove says Popper equivocates. Often, Popper uses success words with their normal meaning. But other times Popper changes the meaning.

It is the word "knowledge", however, which was the target of Popper's most remarkable feat of neutralization. This word bulks large in his philosophy of science (much larger than "discovery"), and in recent years, in particular, the phrase "the growth of knowledge" has been a favorite with him and with those he has influenced most. Some people have professed to find a difficulty, indeed, in understanding how there can be a growth-of-knowledge and yet no accumulation-of-knowledge.

There is accumulation-of-knowledge. Stove gives no cite, but I have a guess at what he's talking about. This quote is from C&R (Conjectures and Refutations) ch. 10 sec. 1, and there's a similar statement in LScD (The Logic of Scientific Discovery).

it is not the accumulation of observations which I have in mind when I speak of the growth of scientific knowledge, but the repeated overthrow of scientific theories and their replacement by better or more satisfactory ones.

The growth of knowledge doesn't consist of accumulating ever more observations (we need ideas). Nor are we simply accumulating more and more ideas, because scientific progress involves refuting, replacing and modifying ideas too. The growth of knowledge is more about quality than quantity.

Continuing the same Stove passage:

But then some people cannot or will not understand the simplest thing,

More ridicule.

and we cannot afford to pause over them. Let us just ask, how does Popper use the word "knowledge"?

Well, often enough, of course, like everyone else including our other authors, he uses it with its normal success-grammar. But when he wishes to give expression to his own philosophy of science he baldly neutralizes it. Scientific knowledge, he then tells us, is "conjectural knowledge". Nor is this shocking phrase a mere slip of the pen, which is what anywhere else it would be thought to be.

Expressing shock and talking about slips of the pen is not how one debates ideas seriously. But let's discuss conjectural knowledge.

Knowledge is good ideas. Sorting out good and bad ideas is one of the main problems in epistemology.

Conjectural serves two purposes. First, it indicates that knowledge is fallible (and lacks authority). Popper doesn't mean justified, true belief. He's not looking for perfect certainty or absolute guarantees against error.

Second, conjecture is the original source of the good ideas that constitute knowledge. Conjecture is, intentionally, an informal, tolerant, inclusive source. Even myths and superstitions can qualify as conjectures. There's no quality filter.

I think Stove's negative reaction has a thought process like this: No quality filter!? But we want good ideas. We need a quality filter or it's all just arbitrary! "Anything goes" can't achieve knowledge, it's irrationalism.

Popper has an answer:

Standard approaches do lots of quality filtering (sometimes all) based on the source of ideas.

Instead, all quality filtering should be done based on the content of ideas. This is done with criticism and human judgement, which lack authority but are good enough.

So we do have a quality filter, it's just designed differently and put in a different place.

For more, see Popper's introduction to C&R, On the Sources of Knowledge and of Ignorance. Excerpt from sec. XV:

The question about the sources of our knowledge can be replaced in a similar way [to the 'Who should rule?' issue]. It has always been asked in the spirit of: ‘What are the best sources of our knowledge—the most reliable ones, those which will not lead us into error, and those to which we can and must turn, in case of doubt, as the last court of appeal?’ I propose to assume, instead, that no such ideal sources exist—no more than ideal rulers—and that *all* ‘sources’ are liable to lead us into error at times. And I propose to replace, therefore, the question of the sources of our knowledge by the entirely different question: ‘*How can we hope to detect and eliminate error?*’

Continuing the same Stove passage:

On the contrary, no phrase is more central to Popper's philosophy of science, or more insisted upon by him. The phrase even furnishes, he believes, and as the title of one of his articles claims, nothing less than the "solution to the problem of induction" [28].

Note the lack of discussion of Popper's position.

In one way this is true, and must be true, because any problem clearly must yield before some one who is prepared to treat language in the way Popper does. What problem could there be so hard as not to dissolve in a sufficiently strong solution of nonsense? And nonsense is what the phrase "conjectural knowledge" is:

More insults.

just like say, the phrase "a drawn game which was won". To say that something is known, or is an object of knowledge, implies that it is true, and known to be true.

This is ambiguous on the key issue of fallibility.

Is Stove saying all knowledge must be infallible and known to be infallible? It must be the proven to be the perfect truth, with complete certainty, so that error is utterly impossible – or else it's not knowledge?

If that's Stove's view of knowledge, then I think he has a choice between irrationalism or skepticism. Because his demands cannot be met rationally.

Or if Stove's position is less perfectionist, then what is it? What allowances are made for fallibility and human limitations? How do they compare to Popper's allowances? And why is Popper mistaken?

(Of course only `knowledge that' is in question here). To say of something that it is conjectural, on the other hand, implies that it is not known to be true.

Does "known to be true" here mean infallibly proven? Or what?

And this is all that needs to be said on the celebrated subject of "conjectural knowledge"; and is a great deal more than should need to be said.

What's going on here is simple. Stove is scornful of a concept he doesn't understand. He doesn't appreciate or discuss the problems in the field. And he doesn't want to. He's unable to state a summary of Popper's view which a Popperian would agree with, and he wants the matter to be closed after three paragraphs.

Sabotaging Logical Expressions

Ch. 2:

What scientists do in such circumstances, Popper says, is to act on a methodological convention to neglect extreme probabilities

For example, how do you know a coin which flips 1000 heads in a row is unfair? Maybe it's a fair coin on a lucky streak.

Well, so what? I'm willing to risk a 2^-1000 chance of misjudging the coin. I'm far more likely to be struck be lightning than get the coin wrong. And the downside of misjudging the coin is small. If the downside were so large that I couldn't tolerate that much risk, I could flip the coin additional times to reduce the risk to my satisfaction (assuming I get more heads, that reduces the probability it's a fair coin).

So Popper offers: if you judge it's not a worthwhile issue to worry about, then don't worry about it. This judgement, like everything, could be a mistake, so it's always held open to criticism. That openness doesn't mean we think it's mistaken or spend our time searching for a mistake, it just means we recognize we have no infallible guarantee against error. We have to make fallible, criticizable judgements about what areas are problematic to focus attention on.

Stove dislikes this approach because he thinks you could do it to dismiss any problem. Stove fears arbitrarily creating a methodological convention to neglect any difficulty. The solution to this is criticizing bad methodological conventions. Stove (correctly) sees problems with some conventions that could be proposed, and those problems can be expressed as criticism.

The problem here is Stove's unfamiliarity with Popperian methods. Plus I think Stove wants methodological rules to guide thinking and reduce the scope for human judgement and creativity.

... Popper actually anticipated it. This is `the Quine-Duhem thesis': that "any statement can be held true come what may, if we make drastic enough adjustments elsewhere in the system [...]. Conversely, [...] no statement is immune to revision" [23].

There's an important logical point here. I wonder what Stove's answer to it is (he doesn't say). Popper offered some help with this issue, but not a full solution. That's OK because Popper's general approach of fallible judgement combined with error correction still works anyway.

Philosopher David Deutsch addressed the Quine-Duhem issue better. His two books offer refinements of Popper. (FoR ch. 1, 3, 7-8; BoI ch. 1-4, 10, 13.)

In short: You may try modifying whatever you want to rescue a statement, but those modifications have meaning and can be criticized. Ad hoc modifications commonly ruin the explanation which gave the idea value in the first place, or contradict vast amounts of existing knowledge without argument. If you can come up with a modification that survives immediate criticism, then it's a good contribution to the discussion (sometimes the error really is elsewhere in the system).

Other Thoughts

Ch. 3:

It is a favorite thesis with him that a scientific theory is, not only never certain, but never even probable, in relation to the evidence for it [3].

Right, because logically there's no such thing as evidence for a theory. There's only evidence which does or doesn't contradict a theory. And any finite set of evidence is logically compatible with (does not contradict) infinitely many theories, and those theories reach basically every conclusion.

What does Stove think of this?

These two theses [the one above and one other] will be acknowledged to be irrationalist enough; and they are ones upon which Popper repeatedly insists.

Stove doesn't present and discuss Popper's solution to the logical difficulties of positive support. Nor does Stove present his own solution. Instead he says it "will be acknowledged" that Popper's view is irrational, without argument. Stove treats it as if Popper only talked about this difficulty without also giving a solution. (The solution, in short, is that negative arguments don't face this difficulty.)

Ch. 3:

Scepticism about induction is an irrationalist thesis itself

Rather than present and discuss Popper's solution to the problem of induction, Stove simply asserts that the only alternative to induction is irrationalism. He goes on to discuss Hume at length rather than Popper.

Ch. 5:

One of these features, and one which is at first sight surprising in deductivists, is this: an extreme lack of rigor in matters of deductive logic.

Because Popper's main positions aren't about deduction. The technical reason that conjectures and refutations is able to create knowledge is that it's evolution, not deduction. The key to evolution is error correction, and that's also the key to Popper's philosophy, but Stove doesn't understand or discuss that. Stove only uses the word "evolution" once (in a Kuhn quote where it means gradual development rather than replication with variation and selection).

A core issue in Popper's philosophy is: "How can we hope to detect and eliminate error?" (as quoted earlier). Stove doesn't understand, present, or criticize Popper's answer to that question.

Note: My comments on Popperian thinking are summary material. There's more complexity. It's a big topic. There are books of details, and I can expand on particular points of interest if people ask questions.

Robert Spillane (RS) is a philosopher who worked with Thomas Szasz for decades. He comments on Critical Rationalism (CR) in his books. I think he liked some parts of CR, but he disagrees with CR about induction and some other major issues. Attempting to clear up some disagreements, I sent him a summary of CR I wrote (not published yet).

Previously I criticized a David Stove book he recommended, responded to him about RSI (we agree), replied positively to his article on personality tests, explained a Popper passage RS didn't understand, and wrote some comments about Popper to him.

RS replied to my CR article with 25 points. Here are my replies:

I am reluctant to comment on your article since it is written in a 'popular' style - as you say it is a summary article. Nonetheless, since you ask.......

I think writing in a popular (clear and readable) style is good. I put effort into it.

Speaking of style, I also think heavy use of quoting is important to serious discussions. It helps with responding more precisely to what people said, rather than to the gist of it. And it helps with engaging with people rather than talking past them.

(I've omitted the first point because it was a miscommunication issue where RS didn't receive my Stove reply.)

2. Your summary article is replete with tautologies which, while true, are trivial. The first paragraph is, therefore, trivial. And from trivial tautologies one can only deduce tautologies.

I’m not trying to approach philosophy by deduction (or induction or abduction), which I consider a mistaken approach.

Here's the paragraph RS refers to:

Humans are fallible. That means we’re capable of being mistaken. This possibility of making a mistake applies to everything. There’s no way to get a guarantee that one of your ideas is true (has no mistakes). There’s no guaranteed way to limit where a mistake could be (saying this part of my idea could be mistaken but not that part) or the size a mistake could be.

This makes claims which I believe most people disagree with or don’t understand, so I disagree that it’s trivial. I think it’s an important position statement to differentiate CR’s views from other views. I wish it was widely considered trivial!

I say, "There’s no way to get a guarantee that one of your ideas is true”. I don’t see how that's a tautology. Maybe RS interprets it as being a priori deducible from word definitions? Something like that? That kind of perspective is not how I (or Popper) approach philosophy.

I wrote it as a statement about how reality actually is, not how reality logically must be. I consider it contingent on the laws of physics, not necessary or tautological. I didn’t discover it by deduction, but by critical argument (and even some scientific observations were relevant). And I disagree with and deny the whole approach of a priori knowledge and the analytic/synthetic dichotomy.

3. Why are informal arguments OK? What is an example of an informal argument? It can't be an invalid one since that would not be OK philosophically, unless one is an irrationalist.

An example of an informal argument:

Socialism is a system of price controls. These cause shortages (when price ceilings are too low), waste (when price floors are too high), and inefficient production (when the controlled prices don’t match what market prices would be). Price floors cruelly keep goods out of the hands of people who want to purchase the goods to improve their lives, while denying an income to sellers. Price ceilings prevent the people who most urgently need goods from outbidding others for those goods. This creates a system of first-come-first-serve (rather than allocating goods where they will provide the most benefit), a shadow market system of friendships and favors (to obtain the privilege of buying goods), and a black market. Socialism sacrifices the total amount wealth produced (which is maximized by market prices), and what do we get in return for a reduction in total wealth? People are harmed!

Szasz’s books are full of informal arguments of a broadly similar nature to this one. He doesn’t write deductions, formal logic, and syllogisms.

Informal arguments are invalid in the sense that they don’t conform to one of the templates for a valid deduction. I don't think that makes them false.

I don’t think it’s irrationalism to think there’s value and knowledge in that price controls argument against socialism, even though it’s not a set of syllogisms and doesn't reduce to a set of syllogisms.

The concept of formal logic means arguments which are correct based on their form, regardless of some of the specifics inserted. E.g. All X are Y. Z is X. Therefore Z is Y.

The socialism argument doesn’t work that way. It depends on the specific terms chosen. If you replace them with other terms, it wouldn’t make sense anymore. E.g. if you swapped each use of "floor" and "ceiling" then the argument would be wrong. Or if you replaced "socialism" with "capitalism" then it'd be wrong because capitalism doesn't include price controls.

The socialism argument is also informal in the sense that it’s fairly imprecise. It omits many details. This could be improved by further elaborations and discussion. It could also be improved with footnotes, e.g. to George Reisman’s book, Capitalism: A Treatise on Economics, which is where I got some of the arguments I used.

Offering finite precision, and not covering every detail, is also something I consider reasonable, not irrationalist. And I’d note Szasz did it in each of his books.

Informal arguments are OK because there’s nothing wrong with them (no criticism refuting their use in general – though some are mistaken). And because informal arguments are useful and effective for human progress (e.g. science is full of them) and for solving problems and creating knowledge.

4. I wasn't aware that there was A key to philosophy of knowledge (metaphor?). And how is 'fixing' mistakes effective if we are condemned to fallibility?

It's not a metaphor, it’s a dictionary definition. E.g. OED for key (noun): "A means of understanding something unknown, mysterious, or obscure; a solution or explanation.”

What does RS mean “condemned” to fallibility? If one puts effort into detecting and correcting errors, then one can deal with errors effectively and have a nice life and modern science. There’s nothing miserable about the ongoing need for critical consideration of ideas.

In information theory, there are methods of communicating with arbitrarily high (though not 100%) reliability over channels with a permanent situation of random errors. The mathematical theory allows dealing with error rates up to but not including 50%! In practice, error correction techniques do not reach the mathematical limits, but are still highly effective for enabling e.g. the modern world with hard disks and internet communications. (Source: Feynman Lectures On Computation, ch. 4.3, p. 107)

The situation is similar in epistemology. Error correction methods like critical discussion don't offer any 100% guarantees, nor any quantifiable guarantees, but are still effective.

5. Critical rationalists leave themselves open to the charge of frivolity if they maintain that the 'sources of ideas aren't very important'. How is scientific progress possible without some 'knowledge' of ideas from the past?

Learning about and building on old ideas is fine.

The basic point here is to judge an idea by what it says, rather than by who said it or how he came up with it.

You may learn about people from the past because you find it interesting or inspiring, or in order to use contextual information to better understand their ideas. For example, I read biographies of William Godwin, his family, and Edmund Burke, in order to better understand Godwin’s philosophy ideas (and because it’s interesting and useful information).

6. Why must we be tolerant with, say, totalitarians? Do you really believe that Hitler could be defeated through argumentation?

I think Hitler could easily have been stopped without violence if various people had better ideas early enough in the process (e.g. starting at the beginning of WWI). And similarly the key to our current struggles with violent Islam is philosophical education –- proudly standing up for the right values. The mistaken ideas of our leaders (and most citizens) is what lets evil flourish.

7. One of the most tendentious propositions in philosophy is 'There is a real world.' Popper's 'realism' is Platonic.

So what if it's "tendentious"? What's the point of saying that? Is that intended to argue some point?

Popper isn't a Platonist and his position is that there is a real, objective reality and we can know about it. I was merely stating his position. Sample quote (Objective Knowledge, ch. 2.3, p. 36):

And Reid, with whom I share adherence to realism and to common sense, thought that we had some very direct, immediate, and secure perception of external, objective reality.

Popper's view is that there is an external, objective reality, and we can know about it. However, all our observations are theory-laden – we have to think and interpret in order to figure out what exists.

8. How can an idea be a mistake if its source is irrelevant?

Its content can be mistaken. E.g. "2+3=6" is false regardless of who writes it.

RS may be thinking of a statement like, "It is noon now." Whether that's true depends on the context of the statement, such as what time it is and what language it's written in. Using context to understand the meaning/content of a statement, and then judging by the meaning/content, is totally different than judging an idea by its source (such as judging an idea to be true or probably true because an authority said it, or because the idea was created by attempting to follow the scientific method).

9. One of the many stupid things Popper said was 'All Life is Problem Solving'. Is having sexual intercourse problem-solving? Is listening to Mozart problem-solving?

Yes.

RS calls it stupid because he don't understand it. He doesn't know what Popper means by the phrase "problem solving". Instead of finding out Popper's meaning, RS interpreted that phrase in his own terminology, found it didn't work, and stopped there. That's a serious methodological error.

Having sex helps people solve problems related to social status and social role, as well as problems related to the pursuit of happiness.

Listening to Mozart helps people solve the problem of enjoying their life.

The terminology issue is why I included multiple paragraphs explaining what CR means in my article. For example, I wrote, "[A problem] can be answering a question, pursuing a goal, or fixing something broken. Any kind of learning, doing, accomplishing or improving. Problems are opportunities for something to be better."

Despite this, RS still interpreted according to his own standard terminology. Understanding other perspectives, frameworks and terminology requires effort but is worthwhile.

The comment RS is replying to comes later and reads:

Solving problems always leads to a new situation where there’s new problems you can work on to make things even better. Life is an infinite journey. There’s no end point with nothing left to do or learn. As Popper titled a book, All Life is Problem Solving.

I brought up All Life is Problem Solving because part of its meaning is that we don't run out of problems.

10. 'All problems can be solved if you know how' is a tautology and has no contingent consequences.

It's not a tautology because there's an alternative view (which is actually far more popular than the CR view). The alternative is that there exist insoluble problems (they couldn't be solved no matter what knowledge you had). If you think that alternative view is wrong on a priori logical grounds, I disagree, I think it depends on the laws of physics.

11. 'Knowledge is power' entails 'power is knowledge' which is clearly false as an empirical generalisation.

"Knowledge is power" is a well known phrase associated with the Enlightenment. It has a non-literal meaning which RS isn't engaging with. See e.g. Wikipedia: Scientia potentia est.

I would be very surprised if RS is unfamiliar with this phrase. I don't know why he chose to split hairs about it instead of responding to what I meant.

12. 'If you have a correct solution, then your actions will work' is a tautology.

It's useful to point out because some people wouldn't think of it. If I omitted that sentence, some readers would be confused.

13. 'Observations play no formal role in creating ideas' is clearly false. Semmelweis based his idea about childbirth fever on observations and inductive inferences therefrom.

RS states the CR view is "clearly false". That's the fallacy of begging the question. Whether it's false is one of the things being debated.

Rather than assume CR is wrong, RS should learn or ask what CR's interpretation of that example is (and more broadly CR's take on scientific discovery). Popper explained this in his books, at length, including going through a variety of examples from the history of science, so there shouldn't be any mystery here about CR's position.

I don't think discussing this example is a good idea because it's full of historical details which distract from explaining issues like why induction is a myth and what can be done instead. If RS understood CR's position on those issues, then he could easily answer the Semmelweis example himself. It poses no particular challenge for CR.

Anyone who can't explain the Semmelweis example in CR terms is not adequately familiar with CR to reject CR. You have to know what CR would say about a scientific discovery like that before you decide CR is "clearly false".

14. 'Knowledge cannot exist outside human minds'. Of course it can if there are no human minds. I agree with Thomas Szasz who, in 'The Meaning of Mind' argued that while we are minded (mind the step) we do not have minds. 'Mind' should only be used as a verb, never as a noun. Popper's mind-body dualism is bad enough, but his pluralism is embarrassing.

I wrote "Knowledge can exist outside human minds." and this changes "can" to "cannot". RS, please use copy/paste for quotes to avoid misquotes.

I'm not a dualist.

It's fine to read my statement as "Knowledge can exist outside human brains" or outside people entirely. The point is knowledge can exist separate from an intelligent or knowing entity.

15. 'A dog's eyes contain knowledge'. I don't understand this since to know x is to know that x is true. Since truth is propositional, dogs don't have to deal with issues of truth. Lucky dogs!

CR disagrees with RS about what knowledge is, and claims e.g. that there is knowledge in books and in genes. Knowledge in genes has nothing to do with a dog knowing anything.

RS, what is your answer to Paley's problem? And what do you think genetic evolution creates?

16. Your use of 'knowledge' is somewhat eccentric if you claim that trees know that x.

I don't claim trees know anything, I claim that the genes in trees have knowledge of how to construct tree cells.

CR acknowledges its view of knowledge is non-standard, but nevertheless considers it correct and important.

17. 'Knowledge is created by evolution' is a tautology if we accept a liberal interpretation of 'created'. If we do not and we assume strict causation, it is false.

That knowledge can be created by evolution is contingent on the laws of physics, not tautological. RS does not state what the "liberal interpretation" he refers to is, nor what "strict causation" refers to, so I don't know how to answer further besides to request that he provide arguments on the matter (preferably arguments that would persuade me that RS understands evolution).

18. Ideas cannot literally replicate themselves.

This is an unargued assertion. Literally, they can. I think RS is simply concluding something is wrong because he doesn't understand it, which is a methodological error.

David Deutsch has explained this matter in The Fabric of Reality, ch. 8:

a replicator is any entity that causes certain environments to copy it.

...

I shall also use the term niche for the set of all possible environments which a given replicator would cause to make copies of it....

Not everything that can be copied is a replicator. A replicator causes its environment to copy it: that is, it contributes causally to its own copying. (My terminology differs slightly from that used by Dawkins. Anything that is copied, for whatever reason, he calls a replicator. What I call a replicator he would call an active replicator.) What it means in general to contribute causally to something is an issue to which I shall return, but what I mean here is that the presence and specific physical form of the replicator makes a difference to whether copying takes place or not. In other words, the replicator is copied if it is present, but if it were replaced by  almost any other object, even a rather similar one, that object would not be copied.

...

Genes embody knowledge about their niches.

...

It is the survival of knowledge, and not necessarily of the gene or any other physical object, that is the common factor between replicating and non-replicating genes. So, strictly speaking, it is a piece of knowledge rather than a physical object that is or is not adapted to a certain niche. If it is adapted, then it has the property that once it is embodied in that niche, it will tend to remain so.

...

But now we have come almost full circle. We can see that the ancient idea that living matter has special physical properties was almost true: it is not living matter but knowledge-bearing matter that is physically special. Within one universe it looks irregular; across universes it has a regular structure, like a crystal in the multiverse.

Add to this that ideas exist physically in brain matter, (in the same way data can be stored on computer disks), and they do cause their own replication.

Understanding evolution in a precise, modern way was Deutsch's largest contribution to CR.

I don't expect RS to understand this material from these brief quotes. It's complicated. I'm trying to give an indication that there's substance here that could be learned. If he wants to understand it, he'll have to read Deutsch's books (there's even more material about memes in The Beginning of Infinity) or ask a lot of questions. I do hope he'll stop saying this is false while he doesn't understand it.

19. You claim that CR 'works'. According to what criteria - logical? empirical? pragmatic? If it is pragmatism - or what Stove calls the American philosophy of self-indulgence' - then all philosophies, religions and superstitions 'work' (for their believers).

CR works logically, empirically, and practically. That is, there's no logical, empirical or practical refutation of its effectiveness. (I'm staying away from the word "pragmatic" on purpose. No thanks!)

What CR works to do, primarily, is create knowledge. The way I judge that CR works is by looking at the problems it claims to solve, how it claims to solves them, and critically considering whether its methods would work (meaning succeed at solving those problems).

CR offers a conception of what knowledge is and what methods create it (guesses and criticism – evolution). CR offers substantial detail on the matter. I know of no non-refuted criticism of the ability of CR's methods to create knowledge as CR defines knowledge.

There's a further issue of whether CR has the right goals. We can all agree we want "knowledge" in some sense, but is CR's conception of knowledge actually the thing we want? Not for everyone, e.g. infallibilists. But CR explains why conjectural knowledge is the right conception of knowledge to pursue, which I don't know any non-refuted criticism of. Further, there are no viable rival conceptions of knowledge that anyone knows how to pursue. Basically, all other conceptions of knowledge are either vague or wrong (e.g. infallibilist). This claim depends on a bunch of arguments – RS if you state your conception of knowledge then I'll comment on it.

20. You are right to say that '90% certain' is an oxymoron. But so is 'conjectural knowledge'.

Here RS interprets "knowledge" and perhaps also "conjectural" in his own terminology, rather than learning what CR means.

The most important part of CR's conception of knowledge is that fallible ideas can be knowledge. Conjectures are fallible.

"Conjectural knowledge" is also an anti-authoritarian concept. Popper is saying that mere guesses (even myths) can be knowledge (if they solve a problem and are subjected to critical scrutiny). An idea doesn't have to be created by an authority-granting method (e.g. deduction, induction, abduction, "the scientific method", etc) or come from an authority-granting source (e.g. a famous scientist) in order to be knowledge.

21. 'Actually, the possibility for further progress is a good thing' is a value judgement. But how can progress be a feature of CR? Was not Thomas Kuhn right to claim that Popper's position leads to rampant relativism (as Kuhn's does).

No, Popper isn't a relativist about anything. Popper wrote a ton about progress and took the position that progress is possible, objective and desirable. (E.g. "Equating rationality with the critical attitude, we look for theories which, however fallible, progress beyond their predecessors" from C&R.) And Popper thought we have objective knowledge, including about value judgements and morality. Some of Popper's comments on the matter in The World of Parmenides:

Every rational discussion, that is, every discussion devoted to the search for truth, is based on principles, which in actual fact are ethical principles.

...

All this shows that ethical principles form the basis of science. The most important of all such ethical principles is the principle that objective truth is the fundamental regulative idea of all rational discussion. Further ethical principles embody our commitment to the search for truth and the idea of approximation to truth; and the importance of intellectual integrity and of fallibility, which lead us to a self-critical attitude and to toleration. It is also very important that we can learn in the field of ethics.

...

Should this new ethics [that Popper proposes] turn out to be a better guide for human conduct than the traditional ethics of the intellectual professions ... then I may be allowed to claim that new things can be learnt even in the field of ethics.

...

in the field of ethics too, one can put forward suggestions which may be discussed and improved by critical discussion

In CR's view, the ability to learn in a field requires that there's objective knowledge in that field. Under relativism, you can't learn since there's no mistakes to correct and no objective truth to seek. So Popper thinks there is objective ethical knowledge.

22. Your claim that 'induction works by inducing' applies also to 'deduction works by deducing'.

The statement "deduction works by deducing" would be a bad argument for deduction or explanation of how deduction works.

Inductivists routinely state that induction works by generalizing or extrapolating from observation and think they've explained how to do induction (rather than recognizing the relation of their statement to "induction works by inducing").

23. Inductivists do have an answer for you. Stove has argued, correctly in my view, that there are good reasons to believe inductively-derived propositions. I paraphrase from my book 'An Eye for an I' (pp.183-4) for your readers who have no knowledge of my book.

'Hume's scepticism about induction - that it is illogical and hence irrational and unreasonable - is the basis for his scepticism about science. His two main propositions are: inference from experience is not deductive; it is therefore a purely irrational process. The first proposition is irrefutable. 'Some observed ravens are black, therefore all ravens are black' is an invalid argument: this is the 'fallibility of induction.' But the second proposition is untenable since it assumes that all rational inference is deductive. Since 'rational' means 'agreeable to reason', it is obvious that our use of reason often ignores deduction and emphasises the facts of experience and inferences therefrom.

Stove defends induction from Hume's scepticism by arguing that scepticism about induction is the result of the 'fallibility of induction' and the assumption that deduction is the only form of rational argument. The result is inductive scepticism, which is that no proposition about the observed is a reason to believe a contingent proposition about the unobserved. The fallibility of induction, on its own, does not produce inductive scepticism because from the fact that inductive arguments are invalid it does not follow that something we observe gives us no reason to believe something we have not yet observed. If all our experience of flames is that they burn, this does give us a reason for assuming that we will get burned if we put our hand into some as yet unobserved flame. This is not a logically deducible reason but it is still a good reason. But once the fallibility of induction is joined with the deductivist assumption that the only acceptable reasons are deductive ones, inductive scepticism does indeed follow.

Hume's scepticism about science is the result of his general inductive scepticism combined with his commitment to empiricism, which holds that any reason to believe a contingent proposition about the unobserved is a proposition about the observed. So the general proposition about empiricism needs to be joined with inductive scepticism to produce Hume's conclusion because some people believe that we can know the unobserved by non-empirical means, such as faith or revelation. As an empiricist Hume rules these means out as proper grounds for belief. So to assert the deductivist viewpoint is to assert a necessary truth, that is, something that is trivially true not because of any way the world is organised but because of nothing more than the meanings of the terms used in it. When sceptics claim that a flame found tomorrow might not be hot like those of the past, they have no genuine reason for this doubt, only a trivial necessary truth.'

What, then, is the bearing of 'all observed ravens have been black' on the theory 'all ravens are black'? Stove's answer is based on an idea of American philosopher Donald Cary Williams, which is to reduce inductive inference to the inference from proportions in a population. It is a mathematical fact that the great majority of large samples of a population are close to the population in composition. In the case of the ravens, the observations are probably a fair sample of the unobserved ravens. This applies equally in the case where the sample is of past observations and the population includes future ones. Thus, probable inferences are always relative to the available evidence.

The claim "there are good reasons to believe inductively-derived propositions" doesn't address Popper's arguments that inductively-derived propositions don't exist.

Any finite set of facts or observations is compatible with infinitely many different ideas. So which idea(s) does one induce?

Note that this argument is not about the "fallibility of induction". So Stove is mistaken when he says that's the source of skepticism of induction. (No doubt it's a source of some skepticism of induction, but not of CR's.) The claim that deduction is the only form of rational argument is also not CR's position. So Stove isn't answering CR. Yet RS said this was an inductivist answer to me.

This is typical. I had an objection to the first sentence following "Inductivists do have an answer for you." It made an assumption I consider false. It then proceeded to build on that assumption rather than answer me.

Where RS writes, "it is still a good reason", no statement of why it's a good reason or in what sense it's "good" or why being good in that sense matters is given. Avoiding some technical details, CR says approximately that it's a good reason because we don't have a criticism of it, rather than for an inductive reason. Why does no criticism matter? What's good about that? Better an idea you don't see anything wrong with than one you do see something wrong with.

Nothing in the paragraphs answers CR. They just demonstrate unfamiliarity with CR's standard arguments. Consider:

When sceptics claim that a flame found tomorrow might not be hot like those of the past, they have no genuine reason for this doubt, only a trivial necessary truth.

Many things in the future are different than the past. So one has to understand explanations of in what ways the future will resemble the past, and in what ways it won't. Induction offers no help with this project. Induction doesn't tell us in which ways the future will resemble the past and in which ways it won't (or in which ways the unobserved resembles the observed and in which ways it doesn't). But explanations (which can be improved with critical discussion) do tell us this.

For example, modern science has an explanation of what the sun is made of (mostly hydrogen and helium), its mass (4.385e30 lbs), why it burns (nuclear fusion), etc. These explanations let us understand in what respects the sun will be similar and different tomorrow, when it will burn out, what physical processes would change the date it burns out, what will happen when it burns out, and so on. Explanations simply aren't inferences from observations using some kind of inductive principle about the future probably resembling the past while ignoring the "in which respects?" question. And the sort of skeptic being argued with in the quote has nothing to do with CR.

I won't get into probability math here (we could do that in the future if desired), but I will mention that Popper already addressed that stuff. And the object of this exercise was to answer CR, but that would take something like going over Popper's arguments about probability (with quotes) and saying why they are mistaken or how to get around them.

24. You state that Popper invented critical rationalism around 1950. I would have thought it was around the mid-1930s.

Inventing CR was an ongoing process so this is approximate. But here are some of the book publication dates:

Objective Knowledge, 1972. Conjectures and Refutations, 1963. Realism and the Aim of Science, 1983 (circulated privately in 1956). The Logic of Scientific Discovery, 1934 (1959 in English). Since I don't consider LScD to be anything like the whole of CR, I chose a later date.

[25.] Your last paragraph is especially unfortunate because you accuse those philosophers who are not critical rationalists (which is most of them) of not understanding 'it enough to argue with it.' With respect Elliot, this is arrogant and ill-informed. Many philosophers understand it only too well and have written learned books on it. Some are broadly sympathetic but critical (David Miller, Anthony O'Hear) while others (Stove, James Franklin) are critical and dismissive. To acknowledge that CR 'isn't very popular, but it can win any debate' is nonsensical and carries the whiff of the 'true believer', which would seem to be self-contradictory for a critical rationalist.

It may be arrogant, but I don't think it's ill-informed. I've researched the matter and don't believe the names you list are counter-examples.

What's nonsensical about an idea which can win in debate, but which most people don't believe? Many scientific ideas have had that status at some time in their history. Ideas commonly start off misunderstood and unpopular, even if there's an advocate who provides arguments which most people later acknowledge were correct.

I think I'm right about CR. I'm fallible, but I know of no flaws or outstanding criticisms of any of my take on CR, so I (tentatively) accept it. I have debated the matter with all critics willing to discuss for a long time. I have sought out criticism from people, books, papers, etc. I've made an energetic effort to find out my mistakes. I haven't found that CR is mistaken. Instead, I've found the critics consistently misunderstand CR, do not provide relevant arguments which address my views, do not address key questions CR raises, and also have nothing to say about Deutsch's books.

I run a public philosophy discussion forum. I have visited every online philosophy discussion forum I could find which might offer relevant discussion and criticism. The results were pathetic. I also routinely contact people who have written relevant material or who just seem smart and potentially willing to discuss. For example, I contacted David Miller and invited him to discuss, but he declined.

Calling this arrogant (Because I think I know something important? Because I think many other people are mistaken?), doesn't refute my interpretation of these life experiences. RS, if you have a proposal for what I should do differently (or a different perspective I should use), I'll be happy to consider it. And if you know of any serious critics of CR who will discuss the matter, please tell me who they are.

None of RS's 25 points were difficult for me to answer. If RS knew of any refutation of CR by any author which I couldn't answer, I would have expected him to be able to pose a difficult challenge for me within 25 comments. But, as usual with everyone, so far nothing RS has said gives even a hint of raising an anti-CR argument which I don't have a pre-existing answer for.

This reply to Robert Spillane follows up on this previous discussion. Here's a full list of posts related to Spillane.

Thank you for your respectful reply. I think we are making progress.

It has been helpful to have you clarify which parts of Popper you accept.

Great.

I am reminded of an interesting chapter in Ernest Gellner's bookRelativism and the Social Sciences, (1985, Ch. 1: 'Positivism and Hegelianism), where he discusses early versus late Popper, supports the former against the latter, and concludes that Popper is (a sort of) positivist. It is an interesting chapter and one I would happily discuss with you.

Like Gellner, I am sympathetic to Popper's 'positivism' but cannot accept his rejection of inductive reasoning. Like you (and Szasz), I reject his 3 Worlds model.

Popper was an opponent of the standard meaning of positivism. I mean something like this dictionary definition: "a philosophical system that holds that every rationally justifiable assertion can be scientifically verified or is capable of logical or mathematical proof, and that therefore rejects metaphysics and theism."

So what sort of "positivism" are you attributing to Popper?

I've ordered the book.

Re your favourite philosophers: you might read Szasz's critical comments on Rand, Branden, Mises, Hayek, Rothbard and Nozick in Faith in Freedom: Libertarian Principles and Psychiatric Practices, (Transaction Publishers, 2004). Even though I received the Thomas Szasz Award in 2006, I told Tom that I could not commit myself to (economic) libertarianism in the way that he did and you appear to do. I accept the primacy of personal freedom but do not accept the economic freedom favoured by libertarians. Indeed, I would have thought that by now, in the age of huge corporations, neo-liberalism is on its last legs. I respect your position, however.

Yes, I'm fully in favor of capitalism.

Yeah, I discussed Faith in Freedom with Szasz, but I don't have permission to share the discussion. One thing Szasz did in the book was use some criticism of Rand from Rothbard. I could tell you criticism of Rothbard's arguments if you wanted, though I think he's best ignored. I do not consider Rothbard or Justin Raimondo to be decent human beings, let alone reliable narrators regarding Rand. I was also unimpressed by Szasz's criticisms of Rand's personal life in the book, and would prefer to focus on her ideas. And I think Szasz made a mistake by quoting Whittaker Chambers' ridiculous slanders.

FYI I only like Rand and Mises from the list of people you mention, and I agree with Szasz that they were mistaken regarding psychiatry. (Rand didn't say much on psychiatry, and some of it good, as Szasz discusses. But e.g. she got civil commitment partly wrong.)

You may be interested to know that Rand spoke very critically of libertarians, especially Hayek and Friedman (who both sympathized with socialism, as did Popper). She thought libertarians were harming the causes of liberty and capitalism with their unprincipled, bad philosophy. I agree with her.

Rand did appreciate Mises because he was substantially different than the others: he was an anti-anarchy classical liberal, a consistent opponent of socialism, and he was very good at economics.

We have criticisms of many libertarian ideas from the right.

Let me mention that I'm not an orthodox Objectivist. I do not like the current Objectivist leadership like Peikoff, Binswanger, and the Ayn Rand Institute. I am banned from the main Objectivist forum for dissenting regarding epistemology (especially induction, fallibilism and perception). I also dissented regarding psychiatry, but discussion of psychiatry was banned before much was said.

If you're interested, I wrote about what the disagreements were and the decision to ban me. I pointed out various ways my views and actions are in line with Ayn Rand's philosophy and theirs aren't. It clarifies some of my philosophy positions:

http://curi.us/1930-harry-binswanger-refuses-to-think

There was no reply, no counter-argument. I am aware that they will hold a grudge for life because I wrote that.

I also made a public record of what I said in my discussions with them:

http://curi.us/1921-the-harry-binswanger-letter-posts

Warning: my comments are book length.

I have spent my career in the space between neo-positivism (Hume, Stove) and a critical existentialism (Sartre, Szasz). You might see inconsistencies here but I have always agreed with Kolakowski who wrote in his excellent book Positivist Philosophy, (pp. 242-3):

'The majority of positivists tend to follow Wittgenstein's more radical rule: they do not simply reject the claims of metaphysics to knowledge, they refuse it any recognition whatever. The second, more moderate version is also represented, however, and according to it a metaphysics that makes no scientific claims is legitimate. Philosophers who, like Jaspers, do not look upon philosophy as a type of knowledge but only as an attempt to elucidate Existenz, or even as an appeal to others to make such an attempt, do not violate the positivist code. This attitude is nearly universal in present-day existential phenomenology. Awareness of fundamental differences between 'investigation' and 'meditation', between scientific 'accuracy' and philosophic 'precision', between 'problems' and 'questioning' or 'mystery' is expressed by all existential philosophers...'

I broadly disagree with attempts to separate some thinking or knowledge from reality.

As an aside: I asked Tom Szasz that since he has been appropriated by some existentialists, whether he accepted that label. He thought about it for an hour and said: 'Yes, I'm happy to be included among the existentialists. However, if Victor Frankl is an existentialist, I'm not!' Frankl, despite his reputation as a humanist/existentialist boasted of having authorised many and conducted a few lobotomies on people without their consent.

Your criticism of the analytic/synthetic dichotomy reminds me of Quine but expressed differently. I disagree with you (and Quine) and agree with Hume, Stove and Szasz (and many others) on this issue. I am confident that had Szasz lived for another 50 years, you would not have convinced him that all propositions are synthetic and therefore are either true or false. He and I believe that the only necessities (i.e necessary truths) in the world are those expressed as analytic propositions and these tell us nothing about the world of (empirical) facts.

I don't believe necessary truths like that exist. I think people mistake features of reality (the actual reality they live in) for necessary truths. In our world, logic works a particular way, but it didn't necessarily have to. People fail to imagine how some things could be otherwise because they are used to the laws of physics we live with.

If you have a specific criticism of my view, I'll be happy to consider it.

I think I would have persuaded Szasz in much less than 50 years, if I'm right. Or else Szasz would have persuaded me. I don't think it would have stayed unresolved.

I found Szasz extraordinarily rational and open to criticism, more so than anyone else I've ever discussed with.

I'm delighted that you do not buy into Dawkins' nonsense about 'memes' even if you use 'ideas' as if they are things. Stove on Dawkins hits the mark.

There may be a misunderstanding here. I do buy into David Deutsch's views about memes! I accept memes exist and matter. But I think memes are popularly misunderstood and don't lead to the conclusions others have said they do.

I know that Szasz disagreed with me about memes. He did not, however, provide detailed arguments regarding evolution.

'Knowledge' and 'idea' are abstract nouns and therefore, as a nominalist, I'm bound to say they don't exist, except as names.

I consider them the names of either physical objects (like chairs) or attributes of physical objects (like the color red). As a computer hard drive can contain a file, a brain can contain an idea.

I encourage my students to rely less on nouns and more on verbs (from which most nouns originated). You asked for two definitions:

To 'know' means 'to perceive or understand as fact or truth' (Macquarie Dictionary, p.978). Therefore 'conjectural knowledge' is oxymoronic.

This is ambiguous about whether the understanding may be fallible or not.

Do you need a guarantee of truth to have knowledge, or just an educated guess which is correct according to your current best-efforts at understanding?

Why can't one conjecturally (fallibly) understand something to be a fact?

Induction: 'the process of discovering explanations for a set of particular facts, by estimating the weight of observational evidence in favour of a proposition which asserts something about the entire class of facts (MD, p.904).

Induction: 'a method of reasoning by which a general law or principle is inferred from observed particular instances...The term is employed to cover all arguments in which the truth of the premise, or premises, while not entailing the truth of the conclusion, or conclusions, nevertheless purports to constitute good reasons for accepting it, or them... With the growth of natural science philosophers became increasingly aware that a deductive argument can only bring out what is already implicit in its premises, and hence inclined to insist that all new knowledge must come from some form of induction. (A Dictionary of Philosophy, Pan Books, 1979, pp.171-2).

I agree that those are typical statements of induction. How do you address questions like:

Which general laws, propositions, or explanations should one consider? How are they chosen or found? (And whatever method you answer, how does it differ from CR's brainstorming and conjecturing?)

When and why is one idea estimated to have a higher weight of observational evidence in favor of it than another idea? Given the situation that neither idea is contradicted by any of the evidence.

I think these issues are very important to our disagreement, and to CR's criticism of induction.

You say that 'inborn theories are not a priori'. But a priori means prior to sense experience and so anything 'inborn'must be a priori be definition.

A priori means "relating to or denoting reasoning or knowledge that proceeds from theoretical deduction rather than from observation or experience" (New Oxford American Dictionary)

Inborn theories, which come from genes, don't come from theoretical deduction, nor from observation. Their source is evolution. This definition offers a false dichotomy.

Another definition (OED):

"A phrase used to characterize reasoning or arguing from causes to effects, from abstract notions to their conditions or consequences, from propositions or assumed axioms (and not from experience); deductive; deductively."

that doesn't describe inborn theories from genes.

inborn theories are like the software which comes pre-installed on your computer, which you can replace with other software if you prefer.

inborn theories don't control your life, it's just that thinking needs a starting point. similar to how your life has a starting time and place, which does matter, but doesn't control your fate.

these inborn theories are nothing like analytical ideas or necessary truths. they're just regular ideas, e.g. we might have inborn ideas about the danger of snakes (the details of which ideas are inborn is largely unknown) which were created because of actual encounters with snakes before we were born. but that's still not created by observation or experience, because genes and evolution can neither observe nor experience.

Spillane wrote previously:

Here is Szasz's logic:

• Illness affects the human body (by definition);
• The 'mind' is not a bodily organ;
• Therefore, the mind cannot be or become ill;
• Therefore mental illness is a myth.
• If 'mind' is really the brain or a brain process;
• Then mental illnesses are brain illnesses.
• Since brain illnesses are diagnosed by objective medical signs,
• And mental illnesses are diagnosed by subjective moral criteria;
• Mental illnesses are not literal illnesses
• And mental illness is still a myth.

If this is not deductive reasoning, then what is?

I denied that this is deduction, and I pointed out that "myth" is introduced for the first time in a conclusion statement, so it doesn't follow the rules of deduction. Spillane now says:

If the example of Szasz's logic is not deductive - the truth of the conclusion is implicit in the premise - what sort of argument is it? If you remove #4, would you accept it as a deductive argument?

I think it deviates from deduction in dozens of ways, so removing #4 won't help. For example, the terms "objective", "subjective" and "literal" are introduced towards the end without using previous premises and syllogisms to establish anything about them. I also consider it incomplete in dozens of ways (as all complex arguments always are). You could try to write it as formal (deductive) logic, but I think you'd either omit most of the content or fail.

I don't think the truth of the conclusion is implicit in the premises. I think many philosophers have massively overestimated what they could translate to equivalent formal deductions. So I regard it simply as an "argument", just like most other arguments which don't fall into the categories non-Popperian philosophers are so concerned with.

And even if some arguments could be rewritten as strict deductions, people usually don't do that, and they can still learn and make progress anyway.

Rather than worrying about what category an argument falls into, CR is concerned with whether you have a criticism of it – that is, an argument for why it's false.

I don't think pointing out "that isn't deduction" is a criticism, because being non-deductive is compatible with being true. (The same comment applies to induction.)

I also don't think that pointing out an idea is incomplete is a criticism without further elaboration. What matters is if the idea can succeed at it's purpose, e.g. solve a problem, answer a question, explain an issue. An idea may do that despite being incomplete in some way because the incompleteness may be
irrelevant.

My epistemological position should be clear from what I have said above - it is consistent with a moderate form of neo-positivism.

That Popper's fallibilism is ill-concealed skepticism has been argued at length, by many Popper scholars, e.g. Anthony O'Hear. It was even argued in the book review mentioned.

I don't care how many people argued something at what length. I only care if there are specific arguments which are correct.

Are you denying that you are fallible (capable of making mistakes)? Do you think you sometimes have 100% guarantees against error?

Or do you just deny the second part of Popper's fallibilism? His claim that, in the world today, mistakes are common even when people feel certain they're right.

If it's neither of those, then I don't know what your issue with fallibilism is.

I have already given you (in a long quote) examples of inductively-derived propositions that are 'reasonable'. Now they may not be reasonable to a deductivist, but that only shows that deductivists have a rigid definition of 'rational', 'reasonable' and 'logical'. Given that a very large number of observations of ravens has found that they are black without exception, I have no good reason to believe the next one will be yellow, even though it is possible. That the next raven may be yellow is a trivial truth since it is a tautology. Accordingly, I have a good reason to believe that the raven in the next room is black.

OK I'll address this topic after you answer my two questions about induction above.

You often ask me for information/arguments that I have already given you

We're partially misunderstanding each other because communication is hard and we have different ways of thinking. I'm trying to be patient, and I hope you will too.

Please address these two questions about induction. Answering with page numbers from a book would be fine if they directly address it.

I've read lots of inductivist explanations and found they consistently don't address these questions in a clear, specific way, with actual instructions one could follow to do induction if one didn't already know how. I've found that sometimes accounts of induction give vague answers, but not actionable details, and sometimes they give specifics unconnected to philosophy. Neither of those are adequate.

1) Which general laws, propositions, or explanations should one consider? How are they chosen or found? (And whatever method you answer, how does it differ from CR's brainstorming and conjecturing?)

2) When and why is one idea estimated to have a higher weight of observational evidence in favor of it than another idea? Given the situation that neither idea is contradicted by any of the evidence.

These are crucial questions to what your theory of induction says. The claimed specifics of induction vary substantially even among people who would agree with the same dictionary definition of "induction".

I've read everything you wrote to me, and a lot more in references, and I don't yet know what your answers are. I don't mind that. Discussion is hard. I think they are key questions for making progress on the issue, so I'm trying again.

As a fallibilist, you acknowledge that the 'real world' is a contingent one and there are no necessary truths. But is not 1+1=2 a necessary truth? Is not 'All tall men are men' a necessary truth since its negation is self-contradictory?

I'll focus on the math question because it's the easier case to discuss first. If we agree on it, then I'll address the A is A issue.

I take it you also think the solution to 237489 * 879234 + 8920343 is a necessary truth, as well as much more complex math. If instead you think that's actually a different case than 1+1, please let me know.

OK, so, how do you know 1+1=2? You have to figure out what 1+1 sums to. You have to calculate it. You have to perform addition.

The only means you have to calculate sums involve physical objects which obey the laws of physics.

You can count on your fingers, with an abacus, or with marbles. You can use a Mac or iPhone calculator. Or you can use your brain to do the calculation.

Your knowledge of arithmetic sums depends on the properties of the objects involved in doing the addition. You believe those objects, when used in certain ways, perform addition correctly. I agree. If the objects had different properties, then they'd have to be used in different ways to perform addition, or might be incapable of it. (For example, imagine an iPhone had the same physical properties as an iPhone-shaped rock. Then the sequences of touches the currently sum 1 and 1 on an iPhone would no longer work.)

Your brain, your fingers, computers, marbles, etc, are all physical objects. The properties of those objects are specified by the laws of physics. The objects have to be used in certain ways, and not other ways, to add 1+1 successfully. What ways work depends on the laws of physics which say that, e.g., marbles don't duplicate themselves or disappear when arranged in piles.

So I don’t think 1+1=2 is a truth independent of the laws of physics. If there's a major, surprising breakthrough in physics and it turns out we're mistaken about the properties of the physical objects used to perform addition, then 1+1=2 might have to be reconsidered because all our ways of knowing it depended on the old physics, and we have to reconsider it using the new physics. So observations which are relevant to physics are also relevant to determining that 1+1=2.

This is explained in "The Nature of Mathematics", which is chapter 10 of The Fabric of Reality by David Deutsch. If you know of any refutation of Deutsch's explanation, by yourself or others, please let me know. Or if you know of a view on this topic which contradicts Deutsch's, but which his critical arguments don't apply to, then please let me know.

I believe that Einstein is closer to the truth of what you call the real world than was Aristotle. So when I'm told by this type of fallibilist that we don't know anymore today than we did 400 years ago, I demur.

Neither Popper nor I believe that "we don't know anymore today than we did 400 years ago".

Given your comments on LSD and the a-s dichotomy, after reading this I conclude that you are a fan of late Popper (LP) and I prefer early Popper (EP).

Yes.

You think EP is wrong, and I think LP is right, so I don't see the point of talking about EP.

(I disagree with your interpretation of EP, but that's just a historical issue with no bearing on which philosophy of knowledge ideas are correct. So I'm willing to concede the point for the purpose of discussion.)

Gellner argued that Popper is a positivist in the logical positivist rather than the Comtean positivist sense. His discussion proceeded from the contrasting of positivists and Hegelians and so he put (early) Popper in the positivist camp - Popper was certainly no Hegelian. Of course, Popper never tired of reminding us that he destroyed the positivism of the Vienna Circle and went to great pains to declare himself opposed to neo-positivism. For example, he says that he warmly embraces various metaphysical views which hard positivists would dismiss as meaningless. Moderate positivists, however, accept metaphysical views but deny them scientific status. Does not Popper do this too, even if some of these views may one day achieve scientific status?

Yes: (Late) Popper accepts metaphysical and philosophical views, but doesn't consider them part of science.

CR (late-CR) says non-science has to be addressed with non-observational criticisms, instead of what we do in science, which is a mix of observational and non-observational criticism.

If by fallibilism you mean searching for evidence to support or falsify a theory, I'm a fallibilist. If, however, you mean embracing Popper's view of 'conjectural knowledge' and the inability, even in principle, or arriving at the truth, then I'm not. I believe, against Popper, Kuhn and Feyerabend, that the history of science is cumulative.

No, fallibilism means that (A) there are no guarantees against error. People are capable of making mistakes and there's no way around that. There's no way to know for 100% sure that a proposition is true.

CR adds that (B) errors are common.

Many philosophers accept (A) as technically true on logical grounds they can't refute, but they don't like it, and they deny (B) and largely ignore fallibilism.

I bring this up because, like many definitions of knowing, yours was ambiguous about whether infallibility is a requirement of knowing. So I'm looking for a clear answer about your conception of knowing.

Quotes are from the book Karl Popper, by Anthony O'Hear (AOH). It's in "The Arguments of the Philosophers" series edited by Ted Honderich. (Be careful, AOH has two other books with titles beginning with "Karl Popper".)

AOH says:

Popper's attempt to dispense with induction is unsuccessful. [ch. 4, p. 57]

AOH says his reason, which he'll attempt to show, is:

any coherent conceptualization of the experience requires the assumption of a stable order in the world. [ch. 4, p. 58, emphasis added]

Previously, AOH wrote:

But, argues Popper, we can see on logical grounds that there is no such thing as a perfect repetition of any event. Similarity in all respects would mean that the two events were really identical, and so there would actually be only one event. So the repetitions we experience are only approximate. But this means that some features of repetition B of event A will be different from some features of A. Thus B is to be seen as a repetition of A only to the extent that we discount those features in which B differs from A. [ch. 2, p. 13]

So AOH ought to address the question: "Stable in which respects?" He ought to know that the world is stable in some respects and not others, just as the future resembles the past in some ways and not others, and any two observations are similar to each other in some ways and not others.

Saying the world is "stable" means just as little as saying two observations are "similar". Claiming a stable world means claiming some things stay the same over time (or at least only change a small amount, according to some suitable measure). Of course not all things stay the same over time.

So AOH needs to say what type of stability he's talking about for his claim to mean anything.

One of the standard problems with inductivists is their routine failure to understand this general problem (that when we compare non-identical things they're always both similar and different, and you have to specify what sort of comparison you're doing). What does AOH do about this issue? Nothing. After the "stable" claim I quoted, he immediately changes the subject to solipsism. He's apparently unaware of this issue, even though he discussed it earlier in the book.

AOH proceeds (p. 59) to talk about regularities and patterns of experience without talking about which ones. Of course there are some regularities and some non-regularities in the world. AOH's approach to epistemology is basically "We live in a stable world, so recognize regularities and project them into the future." This is standard inductivist, and misses the point in the standard ways, such as the issue of which regularities to project into the future and how to find them (how does thinking work? AOH just takes for granted that we find these regularities somehow – that is, his epistemology presupposes intelligent thought and fails to explain how thinking actually works. He starts in the middle.) Then:

Our notion of an objective world, then, is reflected by the degree of continuing order and regularity that is to be found within our perceptions. [ch. 4, p. 59]

But Popper already explained the problem with this, and AOH already included that in this book. There is no such thing as "order" or "regularity" out of context. You have to first say which things you want to be the same which you'll count as being orderly or regular. Different aspects of the world are always similar (orderly, regular) in some ways and different in other ways. AOH doesn't address this.

I also found this bizarre statement:

That a belief in induction is not something which can be dropped without substantial alterations elsewhere in our conceptual scheme is why the failure of Popper to develop a truly non-inductive science is not a chance result, but one with deep roots. [ch 4, p. 60]

But Popper was aware of this issue, and wrote about it, and did develop substantial alterations in our conceptual scheme. I would understand if someone thought Popper's substantial alterations were mistaken, or if someone was unfamiliar with Popper's writing. But AOH has studied Popper a lot, and then is apparently unaware this substantial alterations even exist. AOH even quotes and discusses some of them, but apparently(?) doesn't recognize their meaning and importance. This is just like the similar in which respects issue, where AOH quoted Popper about it and discussed it – but then later on he writes as if he was unaware of it (which I take to mean he doesn't fully understand it).

the assumption that the world is not going to [suddenly become chaotic] [ch 4. p. 61]

The world is already chaotic in some ways and not others. So what does this mean? AOH doesn't say.

Does it mean the world won't suddenly become chaotic in all respects? But what would a world that is chaotic in all respects even mean? AOH doesn't address the issue and it's highly problematic.

One fairly technical way to approach the matter is via the theory of computation: consider whether there exist long bitstrings which can't be compressed by any compression algorithm (or, equivalently, can't be the output of any computer program, in any language, which is much shorter than the bitstring). Such a bitstring would be chaotic in all respects. But the answer is no, such a bitstring doesn't exist.

AOH might imagine that, all of a sudden, all the ways the world is stable stop working, and some new ones take their place. But that doesn't make sense, because no matter what happens, you can always retrospectively find regularities in the bigger picture including both before and after the so-called descent into chaos. All that's happened is this: from the infinitely many regularities compatible with the data you have, you favored some (why those? how were they chosen?), and found out those favored regularities were mistaken. (Meanwhile this so-called descent into chaos is fully compatible with some of the other data-compatible claims about regularities you could have made before it happened.)

So the assumption of the world's stability really means assuming your favored theories are correct. Why did you favor them over other theories, compatible with the same data, which make different predictions about the future? From the perspective of those rival theories, the future you predict is a descent into chaos. So when you say the world won't descend into chaos, you just mean the future will happen as you expect and not as your rivals expect – you mean the world will descend into chaos for the people who disagree with you, just not for yourself.

Thus, I am not simply saying that our ability to distinguish between true experience and illusions depends on our once having experienced an orderly world, but that it depends on the continuance of whatever order we had previously recognized. But to assume this is just what, according to Popper, is deeply irrational, and which should be eliminated from our conceptual scheme. [ch 4. p. 61]

Yes, it is irrational. Because it consists of assuming you're right.

What does "whatever order we had previously recognized" refer to? There are infinitely many theories compatible with the data you've observed previously. To recognize some order means to choose some of those of those theories (why those? why not others?) to provide order to your thinking. Then to assume the continuance of that order means to assume that your choice of which theories to prefer won't turn out to be mistaken in the future.

The solution to all this is what Popper said: critical and explanatory thinking (which is literally evolution). We can only conjecture which of the infinite regularities (or, preferably, explanatory theories) compatible with our data are correct. And we can correct errors with criticism, which is how progress is made. (Part of this is explained by AOH, pp. 171-177)

AOH also objects to Popper's corroboration, and I agree that corroboration is a mistake. I have fixed that aspect of Critical Rationalism. You can find my solution here. For a quick overview, I also offer a free short argument.

Popper is quoted in Relativism and the Social Sciences, by Ernest Gellner, ch. 1, p. 5.:

Many years ago I used to warn my students against the widespread idea that one goes to university in order to learn how to talk, and to write, impressively and incomprehensibly. At the time many students came to university with this ridiculous aim in mind, especially in Germany ... most of those ... who ... enter into an intellectual climate which accepts this kind of valuation ... are lost.

Thus arose the cult of un-understandability, the cult of impressive and high-sounding language ... I suggest that in some of the more ambitious social sciences and philosophies, especially in Germany, the traditional game, which has largely become the unconscious and unquestioned standard, is to state the utmost trivialities in high-sounding languages.

Some of the famous leaders of German sociology ... are ... simply talking trivialities in high-sounding language ... They teach this to their students ... who do the same ... the genuine and general feeling of dissatisfaction which is manifest in their hostility to the society in which they live is, I think, a reflection of their unconscious dissatisfaction with the sterility of their own activities.

The source is given as:

The Positivist Dispute in German Sociology, by T. W. Adorno, Hans Albert, Ralf Dahrendorf, Jürgen Habermas, Harald Pilot and Karl Popper, London, 1976, pp. 294 and 296.

I think it's a misquote or incorrect citation in some way because it skips a page but never has ellipses to skip one or more paragraphs. The only time text is skipped it's within a paragraph. (It could be correct if there's a paragraph that's over a page long, I guess.)

I like the quote and I noticed its similar to Ayn Rand's view.

I wrote this in Feb 2009 and emailed it to Yudkowsky. He didn't reply.

Dear Eliezer Yudkowsky,

I am writing to criticize some of your statements regarding Karl Popper. I hope this will be of interest.

http://yudkowsky.net/rational/bayes

Previously, the most popular philosophy of science was probably Karl Popper's falsificationism - this is the old philosophy that the Bayesian revolution is currently dethroning. Karl Popper's idea that theories can be definitely falsified, but never definitely confirmed, is yet another special case of the Bayesian rules

That isn't Popper's idea because he doesn't believe in definite falsifications. Falsifications are themselves tentative conjectures which must be held open to criticism and reconsidering.

Popper also doesn't assert that confirmations are never definite, rather he denies there is confirmation at all. The reason is that any given confirming evidence for theory T is logically consistent with T being false.

More generally, Popper's philosophy is not about what we can do definitely. He does not address himself to the traditional philosophical problem of what we can and can't be certain of, or what is and isn't a justified, true belief. While he did comment on those issues, his epistemic philosophy is not an alternative answer to those questions. Rather, his positive contributions focus on a more fruitful issue: conjectural knowledge. How do people acquire conjectural knowledge? What is its nature? And so on.

BTW, conjectural knowledge does not mean the probabilistic knowledge that Bayesians are fond of. Probabilistic knowledge is just as much of an anathema to Popper as certain knowledge, because the same criticisms (for example that attempting justification leads to regress or circularity) apply equally well to each.

Your claim at the end of the quote that Popperian epistemology is a special case of Bayesian epistemology is especially striking. Popper considered the Bayesian approach and told us where he stands on it. On page 141 of Objective Knowledge he states, "I have combated [Bayesian epistemology] for thirty-three years."

To say that something which Popper combatted for over three decades is a more general version of his own work is an extraordinary claim. It should be accompanied with extraordinary substantiation, and some account of where Popper's arguments on the subject go wrong, but it is not.

Popper was a hardworking, academic person who read and thought about philosophy extensively, including ideas he disagreed with. He would often try to present the best possible version of an idea, as well as a history of the problem in question, before offering his criticism of it. I would ask that a similar approach be taken in criticizing Popper. Both as a matter of respect, and because it improves discussion.

Gyrodiot commented defending instrumentalism.

I'm going to clarify what I mean about "instrumentalism" and "empiricism". I don't know if we actually disagree or there's a misunderstanding.

FI has somewhat of a mixed view here (reason and observation are both great), and objects to an extreme focus on one or the other. CR and Objectivism both say you don't have to, and should not, choose between reason and observation. We object to the strong "rationalists" who want to sit in an armchair and reason out what reality is like without doing any science, and we object to the strong "empiricists" who want to look at reality and do science without thinking.

Instrumentalism means that theories are only or primarily instruments for prediction, with little or no explanation or philosophical thought. Our view is that observation and prediction are great and valuable, but aren't alone in being so great and valuable. Some important ideas – such as the theory of epistemology itself – are primarily non-empirical.

There's a way some people try to make philosophy empirical. It's: try different approaches and see what the results are (and try to predict the results of acting according to different philosophies of science). But how do you judge the results? What's a good result? More accurate scientific predictions, you say. But which ones? How do you decide which predictions to value more than others? Or do you say every prediction is equal and go for sheer quantity? If quantity, why, and how do you address that with only empiricism and no philosophical arguments? And you want more accurate predictions according to which measures? (E.g. do you value lower error size variance or lower error size mean, or one of the infinitely many possible metrics that counts both of them in some way?)

How do you know which observations to make, and which portion of the available facts to record about what you observe? How do you interpret those observations? Is the full answer just to predict which way of making observations will lead to the most correct predictions later on? But how do you predict that? How do you know which data will turn out useful to science? My answer is you need explanations of things like which problems science is currently working on, and why, and the nature of those problems – these things help guide you in deciding what observations are relevant.

Here are terminology quotes from BoI:

Instrumentalism   The misconception that science cannot describe reality, only predict outcomes of observations.

Note the "cannot" and "only".

Empiricism   The misconception that we ‘derive’ all our knowledge from sensory experience.

Note the "all" and the "derive". "Derive" refers to something like: take a set of observation data (and some models and formulas with no explanations, philosophy or conceptual thinking) and somehow derive all human knowledge, of all types (even poetry), from that. But all you can get that way are correlations and pattern-matching (to get causality instead of correlation you have to come up with explanations about causes and use types of criticism other than "that contradicts the data"). And there are infinitely many patterns fitting any data set, of which infinitely many both will and won't hold in the finite future, so how do you choose if not with philosophy? By assuming whichever patterns are computable by the shortest computer programs are the correct ones? If you do that, you're going to be unnecessarily wrong in many cases (because that way of prediction is often wrong, not just in cases where we had no clue, but also in cases when explanatory philosophical thinking could have done better). And anyway how do you use empiricism to decide to favor shorter computer programs? That's a philosophy claim, open to critical philosophy debate (rather than just being settled by science), of exactly the kind empiricism was claiming to do without.

Finally I'll comment on Yudkowsky on the virtue of empiricism:

The sixth virtue is empiricism. The roots of knowledge are in observation and its fruit is prediction.

I disagree about "roots" because, as Popper explained, theories are prior to observations. You need a concept of what you're looking for, by what methods, before you can fruitfully observe. Observation has to be selective (like it or not, there's too much data to record literally all of it) and goal-directed (instead of observing randomly). So goals and ideas about observation method precede observation as "roots" of knowledge.

Note: this sense of preceding does not grant debating priority. Observations may contradict preceding ideas and cause the preceding ideas to be rejected.

And note: observations aren't infallible either: observations can be questioned and criticized because, although reality itself never lies, our ideas that precede and govern observation (like about correct observational methods) can be mistaken.

Do not ask which beliefs to profess, but which experiences to anticipate.

Not all beliefs are about experience. E.g. if you could fully predict all the results of your actions, there would still be an unanswered moral question about which results you should prefer or value, which are morally better.

Always know which difference of experience you argue about.

I'd agree with often but not always. Which experience is the debate about instrumentalism and empiricism about?

See also my additional comments to Gyrodiot about this.

I believe there are no correct, unaddressed criticisms of Karl Popper’s epistemology (Critical Rationalism – CR). If I'm mistaken, I'd like to be told. If others are mistaken, I'd like them to find out and take an interest in CR.

I've found CR criticism falls into some broad categories, with some overlap:

1. The people who heard Popper is wrong secondhand but didn’t read much Popper and have no idea what CR is actually about. They often try to rely on secondary sources to tell them what CR says, but most secondary sources on CR are bad.

2. The pro-induction people who don’t engage with Popper’s ideas, just try to defend induction. They don’t understand Popper’s criticism of induction and focus on their own positive case for induction. They also commonly admit that some criticisms of induction are correct, but still won’t change their minds or start learning the solution to induction’s flaws (CR).

3. The falsificationism straw man, which misinterprets Popper as advocating a simplistic, false view. (There are some other standard myths too, e.g. that Popper was a positivist.)

4. Critics of The Logic of Scientific Discovery who ignore Popper’s later works and don’t engage with CR's best ideas.

5. Critics with points which Popper answered while he was still alive. Most criticisms of Popper are already answered in his books, and if not there then in this collection of Popper criticism and Popper’s replies. (I linked volume two which has Popper’s replies, you will want volume 1 also.)

If you believe Popper is wrong, then: Do you believe you personally understand CR? And have you looked at Popper’s books and replies to his critics to see if your point is already answered? If so, have you written down why Popper is mistaken? If not, do you believe someone else has done all this? (They understand CR, are familiar with Popper’s books including his replies to his critics, and wrote down why Popper is mistaken.)

Whether it’s by you or someone else, you can reply with a reference to where this is publicly written down in English. I will answer it (or refer you to an answer or get a colleague to answer). Here is what I expect in return: if your reference is mistaken, you will study CR. You were wrong about CR’s falsity, so it’s time to learn it. If you would be unwilling to learn CR even if you agree that your referenced criticism of CR is false, then you shouldn’t have an opinion on CR. If you still wouldn’t want to learn CR even if all your objections were wrong, then you either aren’t participating in the field (epistemology) or shouldn’t be. (I have nothing against lay people as long as they are interested in learning and thinking. I do have something against people, whether lay or philosophy professors, who state their opinion that Popper is wrong but would not be willing to learn about Popper even if they found out their negative beliefs about Popper are false.)

If you believe one of the many criticisms of Popper is correct, but you don’t know which one and don’t want to pick one, then you are not treating the matter rationally. It’s unacceptable if your plan is, on having one criticism answered, to simply pick another one, and repeat indefinitely. You’re welcome to have one good reference which makes multiple important points, but you don’t get to just keep referencing different critical authors repetitively (as each one fails, you pick another) while not reconsidering your own beliefs. You need to stick your own neck out – as I do. If I can’t answer a challenge to CR I will reconsider my views.

If you want to bring up a couple criticisms at the start, which are written in different places, but you won't add any more later, then that could be reasonable – but provide a brief explanation of why it's needed. In this case where you want to bring up multiple points by different authors, I'd expect you to be referencing specific sections or short works, not multiple whole books. E.g. you could reasonably say you have 3 criticisms of Popper, chapter 3 of book X, chapter 7 of book Y, and paper Z.

Alternatively, if Popper is mistaken but no one has actually written correct criticism (including you), then how do you know he's mistaken? Maybe he's not!

Note: I'm interested in criticisms like "Popper's idea X is false b/c Y.", not like "I wasn't convinced by Popper's writing on topic X." (The second one is compatible with Popper being correct, and is too vague to answer.)

Broadly, the reason criticisms of CR fail is the critics do not understand CR. Having read a lot of Popper criticism, I can report this theme is nearly universal in my experience. (There is one problem with CR, which sometimes comes up, which I fixed.) CR is hard to understand because it disagrees with over 2000 years of epistemological tradition. And people in general massively underestimate the effort it takes to understand ideas well. (People seem to think they can read a philosophy book once and understand it, but that isn’t how it works – study and discussion are needed to clear up misunderstandings.) Pointing out misunderstandings of CR, with quotes, is one of the typical ways I answer CR criticisms.

Secondarily, Popper criticism often fails because the critic is much less smart and knowledgeable than Popper (one of the world’s best ever thinkers). I think people can get smarter and more knowledgeable if they make the effort, but most people don’t make that effort in a serious, persistent way and put a ton of time into it. I will not use this as an argument against any particular criticism. It’s not an argument, but it is a part of the world’s intellectual/scholarship situation which I think matters, and it helps explain what’s going on. It’s hard to criticize your intellectual betters, but easy to misunderstand and consequently vilify them. More generally, people tend to be hostile to outliers and sympathize with more conventional and conformist stuff – even though most great new ideas, and great men, are outliers.

See also: CR reading recommendations.

William W. Bartley on Popper:

Sir Karl Popper is not really a participant in the contemporary professional philosophical dialogue; quite the contrary, he has ruined that dialogue. If he is on the right track, then the majority of professional philosophers the world over have wasted or are wasting their intellectual careers. The gulf between Popper's way of doing philosophy and that of the bulk of contemporary professional philosophers is as great as that between astronomy and astrology. [emphasis added]

I agree with this comment. Note it doesn't apply to Ayn Rand, who is also an outcast from the majority of professional philosophers.

The quote wording is not exact. I haven't checked the original document. Sources:

Bartley, W. W. (September–December 1976), "III: Biology - evolutionary epistemology", Philosophia, 6 (3–4): 463–494

Cite found here and here. Those links, and this website all give slightly different wordings for the quote.

Brian Gladish published The Society Most Conducive to Problem Solving: Karl Popper and Piecemeal Social Engineering in The Independent Review. I'm reposting my comments here.

Thanks for sharing the article. I found your comments on Popper’s thinking much more accurate than most secondary sources.

In case you hadn’t seen it yet, I wanted to share Popper’s "The Power Of Television” (After the Open Society, ch. 48). In it, Popper advocates TV censorship, particularly regarding depicting violence. Excerpt:

What I propose is that such an organization be created by the state for all people who are involved in the production of television. Everybody who is connected with it must have a licence. This licence can be withdrawn from him for life, if he acts against certain principles. That is my way of introducing discipline into this subject. Everybody must be organized, and everybody must have a licence. Everybody who is doing something which he should not do by the rules of the organization can lose his licence – the licence can be withdrawn from him by a kind of court. So he is constantly under supervision, and he constantly has to fear that if he does something bad he may lose his licence. This constant supervision is something far more effective than is censorship.

Popper said this in 1992 and was particularly eager to have these ideas widely shared. It shows how limited his "lifetime drift toward classical liberalism” was.

Your article mentions Popper’s "complicated scheme of seminationalization”. I wanted to share with people what that means. The letter is available in After the Open Society, ch. 34. Quote:

The comparatively easy problem is the nationalization problem. I suggest, in brief, that the state should take a share of 51 per cent of the shares of all public companies (= with shares quoted on the Stock Exchange). However, (a) they should not be interfered with in general, only if the situation warrants it, and (b) only 40 per cent, or 41 per cent, of the income should go to the state to start with.

Although I admire and advocate Popper’s epistemology, this is awful.

I had a quick comment on this part of the paper:

But it is somewhat harsh to criticize Popper for this failure [to advocate anarcho-capitalism] because he had contemporaries who were better equipped to make this leap—Mises and Hayek, for example—but who did not.

Why bring up anarchism? That criticism would be harsh, but we can fairly criticize Popper’s rejection of minarchism, minimal and limited government, and classical liberalism.

Here’s the big picture as I see it. Popper gave us:

(1) Critical Rationalism & reason -> (2) linking arguments -> (3) freedom & non-violence -> (4) linking arguments -> (5) interventionist government

His 1-3 were correct and his 4-5 were incorrect. His 1 was especially original and valuable. We can form our own system using Popper’s 1-3 followed by Misean arguments linking freedom & non-violence to e.g. laissez faire capitalism and limited government. Or we could follow with anarchist arguments to replace 4-5. 1-3 function independently of what we think freedom & non-violence imply.

Popper’s 4-5 were unoriginal and added nothing significant to the debate. He basically followed Marx in thinking that true freedom requires the forcible prevention of economic exploitation, e.g. in OSE:

I believe that the injustice and inhumanity of the unrestrained 'capitalist system' described by Marx cannot be questioned

Note how blatantly he contradicts his own fallibilist epistemology which teaches us that all ideas can be questioned.

Anyway, Popper was right to link reason with non-violence (and right to link reason with evolution, to reject induction, etc.), and we can and should use that part of Popper’s thinking without using his Marxist followup.

What do you think?

PS: FYI, there’s a typo in the 12th endnote: “seemto” instead of “seem to”.

This is adapted from a Feb 2013 email. I explain why I don't think all justificationism is infallibilist. Although I'm discussing directly with Alan, this issue came up because I'm disagreeing with David Deutsch (DD). DD claims in The Beginning of Infinity that the problem with justificationism is infallibilism:

To this day, most courses in the philosophy of knowledge teach that knowledge is some form of justified, true belief, where ‘justified’ means designated as true (or at least ‘probable’) by reference to some authoritative source or touchstone of knowledge. Thus ‘how do we know . . . ?’ is transformed into ‘by what authority do we claim . . . ?’ The latter question is a chimera that may well have wasted more philosophers’ time and effort than any other idea. It converts the quest for truth into a quest for certainty (a feeling) or for endorsement (a social status). This misconception is called justificationism.

The opposing position – namely the recognition that there are no authoritative sources of knowledge, nor any reliable means of justifying ideas as being true or probable – is called fallibilism.

DD says fallibilism is the opposing position to justificationism and that justificationists are seeking a feeling of certainty. And when I criticized this, DD defended this view in discussion emails (rather than saying that's not what he meant or revising his view). DD thinks justificationism necessarily implies infallibilism. I disagree. I believe that some justificationism isn't infallibilist. (Note that DD has a very strong "all" type claim and I have a weak "not all" type claim. If only 99% of justificationism is infallibilist, then I'm right and DD is wrong. The debate isn't about what's common or typical.)

Alan Forrester wrote:

[Justification is] impossible. Knowledge can't be proven to be true since any argument that allegedly proves this has to start with premises and rules of inference that might be wrong. In addition, any alleged foundation for knowledge would be unexplained and arbitrary, so saying that an idea is a foundation is grossly irrational.

I replied:

But "justified" does not mean "proven true".

I agree that knowledge cannot be proven true, but how is that a complete argument that justification is impossible?

And Alan replied:

You're right, it's not a complete explanation.

Justified means shown to be true or probably true. I didn't cover the "probably true" part. The case in which something is claimed to be true is explicitly covered here. Showing that a statement X is probably true either means (1) showing that "statement X is probably true" is true, or it means that (2) X is conjectured to be probably true. (1) has exactly the same problem as the original theory.

In (2) X is admitted to be a conjecture and then the issue is that this conjecture is false, as argued by David in the chapter of BoI on choices. I don't label that as a justificationist position. It is mistaken but it is not exactly the same mistake as thinking that stuff can be proved true or probably true.

In parallel, Alan had also written:

If you kid yourself that your ideas can be guaranteed true or probably true, rather than admitting that any idea you hold could be wrong, then you are fooling yourself and will spend at least some of your time engaged in an empty ritual of "justification" rather than looking for better ideas.

I replied:

The basic theme here is a criticism of infallibilism. It criticizes guarantees and failure to admit one's ideas could be wrong.

I agree with this. But I do not agree that criticizing infallibilism is a good reply to someone advocating justificationism, not infallibilism. Because they are not the same thing. And he didn't say anything glaringly and specifically infallibilist (e.g. he never denied that any idea he has could turn out to be a mistake), but he did advocate justificationism, and the argument is about justification.

And Alan replied:

Justificationism is inherently infallibilist. If you can show that some idea is true or probably true, then when you do that you can't be mistaken about it being true or probably true, and so there's no point in looking for criticism of that idea.

My reply below responds to both of these issues.

Justificationism is not necessarily infallibilist. Justification does not mean guaranteeing ideas are true or probably true. The meaning is closer to: supporting some ideas as better than others with positive arguments.

This thing -- increasing the status of ideas in a positive way -- is what Popper calls justificationism and criticizes in Realism and the Aim of Science.

I'll give a quote from my own email from Jan 2013, which begins with a Popper quote, and then I'll continue my explanation below:

Realism and the Aim of Science, by Karl Popper, page 19:

The central problem of the philosophy of knowledge, at least since the Reformation, has been this. How can we adjudicate or evaluate the far-reaching claims of competing theories and beliefs? I shall call this our first problem. This problem has led, historically, to a second problem: How can we justify our theories or beliefs? And this second problem is, in turn, bound up with a number of other questions: What does a justification consist of? and, more especially: Is it possible to justify our theories or beliefs rationally: that is to say, by giving reasons -- 'positive reasons' (as I shall call them), such as an appeal to observation; reasons, that is, for holding them to be true, or at least 'probable' (in the sense of the probability calculus)? Clearly there is an unstated, and apparently innocuous, assumption which sponsors the transition from the first to the second question: namely, that one adjudicates among competing claims by determining which of them can be justified by positive reasons, and which cannot.

Now Bartley suggests that my approach solves the first problem, yet in doing so changes its structure completely. For I reject the second problem as irrelevant, and the usual answers to it as incorrect. And I also reject as incorrect the assumption that leads from the first to the second problem. I assert (differing, Bartley contends, from all previous rationalists except perhaps those who were driven into scepticism) that we cannot give any positive justification or any positive reason for our theories and our beliefs. That is to say, we cannot give any positive reasons for holding our theories to be true. Moreover, I assert that the belief we can give such reasons, and should seek for them is itself neither a rational nor a true belief, but one that can be shown to be without merit.

(I was just about to write the word 'baseless' where I have written 'without merit'. This provides a good example of just how much our language is influenced by the unconscious assumptions that are attacked within my own approach. It is assumed, without criticism, that only a view that lacks merit must be baseless -- without basis, in the sense of being unfounded, or unjustified, or unsupported. Whereas, on my view, all views -- good and bad -- are in this important sense baseless, unfounded, unjustified, unsupported.)

In so far as my approach involves all this, my solution of the central problem of justification -- as it has always been understood -- is as unambiguously negative as that of any irrationalist or sceptic.

If you want to understand this well, I suggest reading the whole chapter in the book. Please don't think this quote tells all.

Some takeaways:

• Justificationism has to do with positive reasons.

• Positive reasons and justification are a mistake. Popper rejects them.

• The right approach to epistemology is negative, critical. With no compromises.

• Lots of language is justificationist. It's easy to make such mistakes. What's important is to look
  out for mistakes and try to correct them. ("Solid", as DD recently used, was a similar mistake.)

• Popper writes with too much fancy punctuation which makes it harder to read.

A key part of the issue is the problem situation:

How can we adjudicate or evaluate the far-reaching claims of competing theories and beliefs?

Justificationism is an answer to this problem. It answers: the theories and beliefs with more justification are better. Adjudicate in their favor.

This is not an inherently infallibilist answer. One could believe that his conception of which theories have how much justification is fallible, and still give this answer. One could believe that his adjudications are final, or one could believe that his adjudications could be overturned when new justifications are discovered. Infallibilism is not excluded nor required.

Looking at the big picture, there is the critical approach to evaluating ideas and the justificationist or "positive" approach.

In the Popperian critical approach, we use criticism to reject ideas. Criticism is the method of sorting out good and bad ideas. (Note that because this is the only approach that actually works, everyone does it whenever they think successfully, whether they realize it or not. It isn't optional.) The ideas which survive criticism are the winners.

In the justificationist approach, rather than refuting ideas with negative criticism, we build them up with positive arguments. Ideas are supported with supporting evidence and arguments. The ones we're able to support the most are the winners. (Note: this doesn't work, no successful thinking works this way.)

These two rival approaches are very different and very important. It's important to differentiate between them and to have words for them. This is why Popper named the justificationist approach, which had gone without a name because everyone took it for granted and didn't realize it had any rival or alternative approaches.

Both approaches are compatible with both infallibilism and fallibilism. They are metaphorically orthogonal to the issue of fallibility. In other words, fallibilism and justificationism are separate issues.

Fallibilism is about whether or not our evaluations of ideas should be subjected to revision and re-checking, or whether anything can be established with finality so that we no longer have to consider arguments on the topic, whether they be critical or justifying arguments.

All four combinations are possible:

Infallible critical approach: you believe that once socialist criticisms convince you capitalism is false, no new arguments could ever overturn that.

Infallible justificationist approach: you believe that once socialist arguments establish the greatness of socialism, then no new arguments could ever overturn that.

Fallible critical approach: you believe that although you currently consider socialist criticisms of capitalism compelling, new arguments could change your mind.

Fallible justificationist approach: you believe that although you currently consider socialist justifying arguments compelling (at establishing the greatness and high status of the socialism, and therefore its superiority to less justified rivals), you are open to the possibility that there is a better system which could be argued for even more strongly and justified even more and better than socialism.

BTW, there are some complicating factors.

Although there is an inherent asymmetry between positive and negative arguments (justifying and critical arguments), many arguments can be converted from one type to the other while retaining some of the knowledge.

For example, someone might argue that the single particle two slit experiment supports (justifies) the many-worlds interpretation of quantum physics. This can be converted into criticisms of rivals which are incompatible with the experiment. (You can convert the other way too, but the critical version is better.)

Another complicating factor is that justificationists typically do allow negative arguments. But they use them differently. They think negative arguments lower status. So you might have two strong positive arguments for an idea, but also one mild negative argument against it. This idea would then be evaluated as a little worse than a rival idea with two strong positive arguments but no negative arguments against it. But the idea with two strong positive arguments and one weak criticism would be evaluated above an idea with one weak positive argument and no criticism.

This is easier to express in numbers, but usually isn't. E.g. one argument might add 100 justification and another adds 50, and then a minor criticism subtracts 10 and a more serious criticism subtracts 50, for a final score of 90. Instead, people say things like "strong argument" and "weak argument" and it's ambiguous how many weak arguments add up to the same positive value as a strong argument.

In justification, arguments need strengths. Why? Because simply counting up how many arguments each idea has for it (and possibly subtracting the number of criticisms) is too open to abuse by using lots of unimportant arguments to get a high count. So arguments must be weighted by their importance.

If you try to avoid this entirely, then justificationism stops functioning as a solution to the problem of evaluating competing ideas. You would have many competing ideas, each with one or more argument on their side, and no way to adjudicate. To use justificationism, you have to have a way of deciding which ideas have more justificationism.

The critical approach, properly conceived, works differently than that. Arguments do not have strengths or weights, and nor do we count them up. How can that be? How can we adjudicate between competing ideas with out that? Because one criticism is decisive. What we seek are ideas we don't have any criticisms of. Those receive a good evaluation. Ideas we do have criticisms of receive a bad evaluation. (These evaluations are open to revision as we learn new things.) (Also there are only two possible evaluations in this system. The ideas we do have criticisms of, and the ideas we don't. If you don't do it that way, and you follow the logic of your approach consistently, you end up with all the problems of justificationism. Unless perhaps you have a new third approach.)

This wrote this on an Objectivist discussion forum in 2013.

http://rebirthofreason.com/Forum/Dissent/0265.shtml

I wrote:

Observe what? There are always many many things you could observe. Real scientific observation is selective.

Perform which action? There are many many actions one could perform. Real scientific action is selective.

Which patterns? There's always many many patterns.

In each case, being selective requires complex (critical) thinking. Ideas come first. Induction is supposed to explain how thinking works, but actually presupposes it.

Merlin Jetton replied:

Okay. Give us your answer to these questions. Please give us simple methods that cover all possible cases. How do we delimit those infinitely many possible conjectures?

(Following Popper.) We don't run into all the same problems because we use different methods in the first place.

We don't start with observation, scientific experiment, or finding patterns. All of those come later, after you already have various ideas. Then you do them according to your ideas. This is not problematic in general. It is a problem when you say stuff is "step 1" that actually presupposes ideas, and then claim your set of steps is a solution in epistemology and is how we get ideas.

We have a different approach that is not like induction and avoids many of induction's problems. By using different methods some problems never come up. We never have the problem of figuring out what to observe before having ideas, for example, because we say ideas come first before observations.

How are ideas learned then? Not from observations. Ideas come first. That's not to say observations are excluded. Observations are very useful. But first you need some ideas. Then you can observe (selectively, according to your ideas about what is important, what is interesting, what is notable, what is relevant to problems of interest, what clashes with your expectations, etc, etc ... and if your way of observing doesn't work out you can improve it with criticism, you can change and adjust it) and use the observations to help with further ideas (in a critical role – they rule things out).

Now this is a hard issue and you haven't read the literature and don't be too ambitious about how much you expect to learn from a summary. But anyway, because it's hard I'm going to split it up. First we'll consider an adult who wants to learn something. Then we could talk about how a child gets started after. I'll save that for later if the adult explanation goes over OK. The child is the harder case. I think it's too much to do the child first, all at once.

So, one of Popper's insights is that starting places aren't so important. I'm guessing this sounds dumb to you, because you're a foundationalist and think you have to start with the right foundations/premises/basis and then build up from there, step by step, making sure not to introduce errors or contradictions as you go. And Popper criticized and rejected that approach and offered a significantly different approach.

So let me try to explain what Popper's approach is like. People make mistakes. People are fallible. Errors are common. People mess up all the time. This isn't skepticism. People also get things right, learn, acquire knowledge, make scientific progress, etc, etc... But it's important to understand how easy it is to make mistakes. Knowledge is possible but hard to come by. To get knowledge you have to put a ton of effort into dealing with the problem of mistakes. I think if you read this the right way, you could agree with it. Objectivism recognizes that lots of philosophies go wrong and using the right methods is important and makes a big difference and some stuff like that.

So, OK, error is common and a big part of epistemology and philosophy is how you deal with error. What are you going to do about it? One school of thought tries to avoid errors. You use the right methods and then you get the right answers. That sounds very plausible but I don't think it's the right approach. I'll try to talk about Popper's approach instead. Popper's approach is you do try to avoid errors but you're never going to avoid all of them in the first place. That's not the primary most important thing. Whatever you do, some errors are going to get through. What you really have to do is set up mechanisms to identify and correct errors.

Popper applied this approach widely. Take politics and political systems. One of Popper's big ideas about politics is that trying to elect the right ruler is the wrong thing to focus on. Electing the right guy is trying to avoid errors. Yes you should put some effort into that but you can't do it perfectly and it's not the most important issue. What is the most important issue? That errors can be identified and corrected. In politics that means if you elect the wrong guy you find out fast, and you can get rid of him fast and you can get rid of him without violence. Popper called the wrong approach the "Who should rule?" problem and said most political philosophy argues about who should rule, when it should be focussing a lot more on how to set up political systems capable of correcting mistakes about who gets to rule.

What about epistemology? "Which ideas should we start with?" is a bit like "Who should rule?" You're never going to get it perfect and it shouldn't be the primary focus of your attention. Instead you want to set things up so if you start with the wrong ideas you can find out about the mistake and fix it quickly, easily, cheaply.

error correction is (a lot) more important than starting in a good place. look at it another way. if you start in a bad place but keep making progress, after a while you'll get to a good place and keep going. but if you start in a good place but aren't correcting errors, there is no progress, things never get better, long term you're doomed. so error correction is the more crucial thing that you really need.

so how can adults be selective? how can they decide what scientific experiments to do or which actions and results to investigate? how can they decide what patterns to look for? answer: they already have ideas about that. they can use the ideas they already have. that's ok! they don't need me to tell them some perfect answer. i could give them some advice and there could be some value in it, but it doesn't matter so much. they should start with the ideas they already have, use those, and then if something goes wrong they can make adjustments to try to do something about it. (and they can also philosophically examine their ideas and try to criticize instead of waiting for something noticeable to go wrong.)

in one sense, we're both advocating the same thing. people can and do use the ideas they already have about how to be selective, what issues to focus on, which patterns are notable, and more. but we Popperians know that is what's going on, and know how to keep making progress from there even if people aren't great at it. inductivists on the other hand think they have this method from first principles that is how people think but actually it smuggles in all sorts of common sense and pre-existing ideas as unexamined, uncriticized premises. and that's a really bad idea. those premises being smuggled in are good enough to start with, but what you really need to do is examine and criticize them!

i have not addressed how children/infants get started. i also haven't explained how thinking works at a lower level. (being able to criticize and correct errors requires thinking. how is that done?). we can get to those next if what i'm saying so far goes over ok. also the very short answer for how thinking works is that evolution is the only known theory for how knowledge can be created from non-knowledge. human thinking, at a low level, uses an evolutionary process to create knowledge. (i mean thinking literally uses evolution, not metaphorically. and no i'm not saying you consciously do that).

I wrote this at an Objectivist forum in 2013.

http://rebirthofreason.com/Forum/Dissent/0261.shtml

Popper is by no means perfect. The important thing is the best interpretations (that we can think of) of his best ideas. The comment below about "animals" is a good example. I do not agree with his attitude to animals in general, and I'm uncomfortable with this statement. However, everything he said about animals (not much) can be removed from his epistemology without damaging the important parts.

Popper made some bad statements about epistemology, and some worse ones about politics. I don't think this should get in the way of learning from him. That said, I agree with Popper's main points below.

1) Can you show if Popper ever fully realized that the falsification of a universal positive proposition is a necessary truth? In other words, if a black swan is found, then the proposition "All swans are white" is falsified, but more than that, it is absolutely falsified (which is a form of absolute knowledge/absolute certainty)? Even if you can't, please discuss.

No, Popper denied this. The claim that we have found a black swan is fallible, as is our understanding of its implications.

Fallibility is not a problem in general. We can act on, live with, and use fallible knowledge. However, it does start to contradict you a lot when you start saying things like "absolute certainty".

Rand isn't fully clear about this. Atlas Shrugged:

"Do not say that you're afraid to trust your mind because you know so little. Are you safer in surrendering to mystics and discarding the little that you know? Live and act within the limit of your knowledge and keep expanding it to the limit of your life. Redeem your mind from the hockshops of authority. Accept the fact that you are not omniscient, but playing a zombie will not give you omniscience—that your mind is fallible, but becoming mindless will not make you infallible—that an error made on your own is safer than ten truths accepted on faith, because the first leaves you the means to correct it, but the second destroys your capacity to distinguish truth from error. In place of your dream of an omniscient automaton, accept the fact that any knowledge man acquires is acquired by his own will and effort, and that that is his distinction in the universe, that is his nature, his morality, his glory.

"Discard that unlimited license to evil which consists of claiming that man is imperfect. By what standard do you damn him when you claim it? Accept the fact that in the realm of morality nothing less than perfection will do. But perfection is not to be gauged by mystic commandments to practice the impossible [...]

Here Rand accepts fallibility and only rejects misuses like claiming man is "imperfect" to license evil. Man's imperfection is not an excuse for any evil -- agreed.

Rand has just acknowledged that man and his ideas and achievements are fallible. But then she decides to demand moral "perfection". Which must mean some sort of contextual, achievable perfection -- not the sort of infallible, omniscient perfection Popper rejects and Rand acknowledges as impossible.

It's the same when Rand talks about "certainty" which is really "contextual certainty" which is open to criticism, arguments, improvement, changing our mind, etc... (Only in new contexts, but every time anyone thinks of anything, or any time passed, then the context has changed at least a little. So the new context requirement doesn't cause trouble.)

2) Can you offer something to redeem Popper of seemingly damning quotes such as:

In so far as a scientific statement speaks about reality, it must be falsifiable: and in so far as it is not falsifiable, it does not speak about reality.

... which preemptively denies the possibility of axiomatic concepts (i.e., the possibility of statements that speak about reality, but are not, themselves, falsifiable).

Any statement which speaks about reality is potentially falsifiable (open to the possibility of criticism using empirical evidence) because, if it speaks about reality, then it runs the risk of being contradicted by reality.

Popper does deny axiomatic concepts, meaning infallible statements. Statements that you couldn't even try to argue with, potentially criticize, question, or improve on. All ideas should be open to the possibility of critical questioning and progress.

There is a big difference between open to refutation and refuted. What's wrong with keeping things open to the potential that, if someone has a new idea, we could learn better in the future?

"If realism is true, if we are animals trying to adjust ourselves to our environment, then our knowledge can be only the trial-and-error affair which I have depicted. If realism is true, our belief in the reality of the world, and in physical laws, cannot be demonstrable, or shown to be certain or 'reasonable' by any valid reasoning. In other words, if realism is right, we cannot expect or hope to have more than conjectural knowledge."

... which preemptively denies the possibility of arriving at a necessary truth about the world.

Conjectural knowledge (or trial-and-error knowledge) is Popper's term for fallible knowledge. It's objective, effective, connected to reality, etc, but not infallible. We improve it by identifying and correcting errors, so our knowledge makes progress.

We cannot establish our ideas are infallibly correct, or even that they are good or reasonable. Such claims (that some idea is good) never have authority. Rather, we accept them as long as we don't find any errors with them.

I think this is different than Objectivism, but correct. Well, sort of different. The following passage in ITOE could be read as something kind of like a defense of this Popperian position (and I think that is the correct reading).

One of Rand's themes here, in my words, is that fallibility doesn't invalidate knowledge.

The extent of today’s confusion about the nature of man’s conceptual faculty, is eloquently demonstrated by the following : it is precisely the “open-end” character of concepts, the essence of their cognitive function, that modern philosophers cite in their attempts to demonstrate that concepts have no cognitive validity. “When can we claim that we know what a concept stands for?” they clamor—and offer, as an example of man’s predicament, the fact that one may believe all swans to be white, then discover the existence of a black swan and thus find one’s concept invalidated.

This view implies the unadmitted presupposition that concepts are not a cognitive device of man’s type of consciousness, but a repository of closed, out-of-context omniscience —and that concepts refer, not to the existents of the external world, but to the frozen, arrested state of knowledge inside any given consciousness at any given moment. On such a premise, every advance of knowledge is a setback, a demonstration of man’s ignorance. For example, the savages knew that man possesses a head, a torso, two legs and two arms; when the scientists of the Renaissance began to dissect corpses and discovered the nature of man’s internal organs, they invalidated the savages’ concept “man”; when modern scientists discovered that man possesses internal glands, they invalidated the Renaissance concept “man,” etc.

Like a spoiled, disillusioned child, who had expected predigested capsules of automatic knowledge, a logical positivist stamps his foot at reality and cries that context, integration, mental effort and first-hand inquiry are too much to expect of him, that he rejects so demanding a method of cognition, and that he will manufacture his own “constructs” from now on. (This amounts, in effect, to the declaration: “Since the intrinsic has failed us, the subjective is our only alternative.”) The joke is on his listeners: it is this exponent of a primordial mystic’s craving for an effortless, rigid, automatic omniscience that modern men take for an advocate of a free-flowing, dynamic, progressive science.

One of the things that stands out to me in discussions like this is that all today's Objectivists seem (to me) more at odds with Popper than Rand's own writing is.

I'll close with one more relevant ITOE quote:

Man is neither infallible nor omniscient; if he were, a discipline such as epistemology—the theory of knowledge—would not be necessary nor possible: his knowledge would be automatic, unquestionable and total. But such is not man’s nature. Man is a being of volitional consciousness: beyond the level of percepts—a level inadequate to the cognitive requirements of his survival—man has to acquire knowledge by his own effort, which he may exercise or not, and by a process of reason, which he may apply correctly or not. Nature gives him no automatic guarantee of his mental efficacy; he is capable of error, of evasion, of psychological distortion. He needs a method of cognition, which he himself has to discover: he must discover how to use his rational faculty, how to validate his conclusions, how to distinguish truth from falsehood, how to set the criteria of what he may accept as knowledge. Two questions are involved in his every conclusion, conviction, decision, choice or claim: What do I know?—and: How do I know it?