Kant does not think that the silly commandment "universalize your maxims" is the be-all and end-all of ethics or that it provides us with some sort of general decision procedure that is supposed to tell us what to do under all circumstances.

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.

Fichte takes an I or free will to be not a thing or being but an act which is not undetermined but self-determined, in accordance with reasons or norms rationally self-given.

Kant certainly was sympathetic with the metaphysical tradition of rational theology that he criticized.

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.

Smith could not be expected to have anticipated the horrors that were to come. But even in his own time, he was a defender of certain state actions that he thought necessary in order to safeguard the good effects of commercial society (Smith did not speak of 'capitalism' and was acquainted only with an early undeveloped form of it). Among these state actions the chief was general public education.

Clearly no working class movement ever came about that was able to do what Marx was hoping for.