There are two bad philisophical ideas called Consequentialism and Deontology. The first means judging moral theories, based on their consequences. The second, means judging moral theories, based on principles.

One wonders how one is supposed to judge consequences without having any principles to judge them on.

And one wonders how one is supposed to decide what principles are good, without thinking about their consequences.

Also, in the limit, the two approaches are convergent. ("In the limit" is such a great phrase! Thanks Kolya ^_^)