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.

When people think that moral problems can be solved by some simple strategy of calculation, that sets them up for ghastly overreaching. They think they can turn everything into a "science" the way mechanics was turned into a science in the seventeeth century. They want to turn everything over to technocrats and social engineers. They become shortsighted or simplistic about their ends, and they disastrously overestimate their ability to acquire the information they need to make the needed calculations.

Kant does not think there is anything wrong with being beneficent from sympathy. He thinks we have a duty to cultivate sympathetic feelings by participating in the situations of others and acquiring an understanding of them. He thinks we also have a duty to make ourselves into the kind of person for whom the recognition that something is our duty would be a sufficient incentive to do it (if no other incentives were available to us). That's what he means by "the duty to act from the motive of duty".

Virtues consist not only of acting in certain ways, but in ways of caring and feeling.

Adam Smith saw the greed of modern capitalism for what it was - a form of destructive ambition that may have favorable effects on the productive capacities of society, but which is of no direct benefit to anyone - not even to the greedy themselves, whose illusory chase after a will-o-the-wisp leaves them morally bankrupt and unhappy.

Hegel's theory of recognition is basically derived from Fichte, who is its real author.

Not only our moral life, but even our use of theoretical reason - on which we rely in rationally inquiring into nature - presupposes that we are free.