I think that both Mill and Sidgwick are great and admirable philosophers, from whom we still have a lot to learn. I would not favor a form of Kantianism (if there is such a form) that treats Mill's or Sidgwick's moral philosophy with disrespect.

Kant has been famous for his rejection of eudaimonism, but I think Kantian ethics has a great deal in common with Aristotle, and some things in common with Stoicism as well. The traditions tend, I believe, to talk past each other when it comes to happiness or eudaimonia.

Kant can provide, and has provided, a good model for philosophers to think about the relation of metaphysics to science and scientific methodology.

It has taken me a long time to realize where I most disagree with Marx. His assessment of capitalism is far too favorable. He took its instability, inhumanity and irrationality to be signs that it was a merely transitional form, which had delivered into humanity's hands the means to a much better way of life than any that have ever existed on earth. Marx could not bring himself to believe that our species is so benighted, irrational and slavish that it would put up with such a monstrous way of life.

In fact, if you read what Kant has to say about feeling, desire and emotion, you see that he is not at all hostile to these. He is suspicious of them insofar as they represent the corruption of social life (here he follows Rousseau), but he also thinks a variety of feelings (including respect and love of humanity) arise directly from reason - there is, in other words, no daylight between the heart and the head regarding such feelings.

I could identify for virtually every important figure in the history of modern continental philosophy an idea (or more than one) absolutely central to that philosopher's thought, whose original author was Fichte.

I think the contribution people make is not proportionate to their fame or success. In fact, I think the relation is often inverse.