Consider the following statement:
Everyone does what they believe to be right. Hitler and Stalin may have been profoundly evil men, but they believed in the rectitude of what they were doing. When people do what is wrong, it is because they lack moral knowledge. That's just what it is to be evil.
By the same token, anyone who really knows what is right, will do what is right. Jeremy didn't stop and help that old lady by the side of the road. Today he is feeling all guilty and says he knew he should have. But that's not correct. If he knew he should have, then he would have. That's just what it is to have moral knowledge.
Do you agree with this? Why or why not? Do you think this is more intuitively compelling than the same sort of argument made with respect to non moral contexts? For example, if someone were to say: If you really knew your glasses were on your head, you wouldn't have been looking for them just now in the drawer. Why or why not?