The science of the moral sense also alerts us to ways in which our psychological makeup can get in the way of our arriving at the most defensible moral conclusions. The moral sense, we are learning, is as vulnerable to illusions as the other senses. It is apt to confuse morality per se with purity, status and conformity. It tends to reframe practical problems as moral crusades and thus see their solution in punitive aggression. It imposes taboos that make certain ideas indiscussible. And it has the nasty habit of always putting the self on the side of the angels.