We totally misunderstand both his aims and his contribution if we try to read into Marx some anticipation of either the modest successes or the disastrous failures of those who later thought they were acting in his name.

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".

I do not know how much my own work has achieved, and I must not pretend it has done more than it has.

It seems to me self-evident that it is worthwhile to understand the best thoughts of the past, to appropriate them, to criticize them.

I am a one-trick pony. But I have worked hard at something I would have liked to do even if I weren't paid a penny for it, and made a good living at it. You can't be luckier than that in this life, no matter who you are or what you do.

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

Kantian ethical theory distinguishes three levels: First, that of a fundamental principle (the categorical imperative, formulated in three main ways in Kant's Groundwork); second, a set of duties, not deduced from but derived from this principle, by way of its interpretation or specification, its application to the general conditions of human life - which Kant does in the Doctrine of virtue, the second main part of the Metaphysics of Morals; and then finally an act of judgment, through which these duties are applied to particular cases.