Consequentialist theories begin with a very simple and undoubtedly valid point: Every action aims at a future end, and is seen as a means to it.

Some of Kant's particular moral opinions, either because he shared the prejudices of his time, or because of his own personal crotchets, can strike sensible people as ridiculous or offensive. But in my view, his own theory provides us with the resources (the best resources available, I believe) to correct his own personal errors or cultural prejudices.

Kant does not regard freedom as an item of faith because it is too basic to our agency to be related to any end.

Kant's system of duties constitutes a Doctrine of Virtue because the duties also indicate what kinds of attitudes, dispositions and feelings are morally virtuous or vicious.

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."

What is central to morality is rational self-constraint (acting from duty), in cease where there is no other incentive to do your duty except that the moral law commands it.

It is actually a nice question how far Descartes himself endorses the monological and metaphysically dualistic theory of mind associated with his name and his legacy in early modern philosophy. But Fichte does reject this tradition, by suggesting that an immaterial thinking substance is an incoherent notion, and a rational being whose rationality was not developed through communication with others is a transcendental impossibility.