Not only in order to act morally, but even to formulate theoretical questions, devise experiments, choose which ones to perform and what conclusions to draw from then - we must presuppose that we are free. That's the sense in which it is true that for Kant "we must assume we are free."

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.

We can treat human responses to cognitions as involving law-like connections grounded on free choices which show themselves in our character.

Since the Enlightenment, popular religion has rejected the Enlightenment path and transformed itself into a bastion of resistance against reason.

The Russian revolution did not occur until a generation after Marx's death. He was not involved with it, or with what came after it. His works do not describe post-capitalist society, and a fortiori they do not recommend any part of what the Soviet Union did.

From the beginning, there has been a tension in the reception of the Kantian idea of autonomy. If you emphasize the 'nomos' (the law), then you get one picture: the objectivity of ethics. If you emphasize the 'autos' - the self - you get the idea that we make the law. Kant never hesitated in his choice between the two emphases. He emphasizes the nomos (the universal and objective validity of the law).

It would be nice, wouldn't it? if we could get comfortable about the problem of freedom. Kant thinks that we can't.