Utilitarians are usually empiricists who think they can solve every problem by accumulating enough empirical facts. They do not realize that thinking as well as experience is necessary to know anything or get anything right.

Kant does not think that along with choice of an action we also choose in each case the motive from which we do it. He thinks all is well if I act beneficently, realizing that it is my duty but also having sympathetic feelings for the person I help. But I ought to strive to be the sort of person who would still help even if these feelings were absent. And it is such a case that he presents when the sympathetic friend of humanity finds his sympathetic feelings overclouded by his own sorrows, and still acts beneficently from duty.

Consequentialist theories pretend that we can set some great big ends (the general happiness, human flourishing), provide ourselves with definite enough conceptions of them to make them the objects of instrumental reasoning, and then obtain enough reliable information about what actions will best promote them that we could regulate our conduct by these considerations alone.

Kant regards the universalizability test for maxims as focused on a very special sort of situation: one where the agent is tempted to make an exception to a recognized duty out of self-preference. The universalizability test is supposed help the agent to see, in a particular case of moral judgment, that self-preference is not a satisfactory reason for exempting yourself from a duty you recognize. Kant thinks, as a matter of human nature, that this situation arises often enough and that we need a canon of judgment to guard against it.

Kant thinks of judgment as a special faculty or talent of the mind, not reducible to discursive reasoning but cultivated through experience and practice.

Adam Smith was aware of the way that economic interests could have a distorting and destructive effect both on the market and on politics.

It is rational to choose the right means to your ends to develop very elegant abstract formal theories of rational choice, and then turn these into what look like moral theories. Philosophers tend to be ravished by the formal beauty of such theories, and they don't pay much attention to the fact that our human limitations make them pretty useless in practice, while the simple point about instrumental reasoning is too shallow to be of much real moral interest.