As with many metaphysical and religious questions, Kant thinks they lie beyond our power to answer them. If you can't stand the frustration involved in accepting this, and insist on finding some more stable position which affords you peace of mind and intellectual self-complacency, then you will find Kant's position "problematic" in the sense that you can't bring yourself to accept it. You may try to kid yourself into accepting either some naturalistic deflationary answer to the problem or some dishonest supernaturalist answer.

In the mid-1960s, as hard to believe as it may be now, choosing to go into academic philosophy was not an imprudent career choice. There were lots of academic jobs in philosophy then.

If being "iron headed" is to be lacking such feelings, then Kant's position is that an ironheaded person could not be a moral agent because such a person would not be rational.

Empiricist philosophy always tends to be anti-philosophy (and is often proud of it).

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 thinks we can show that there is no contradiction in supposing we are free.

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.