What are we to think of the shortsightedness of the great mass of people who are content to do nothing about it, and even worse, the greed or venality of the rich and powerful who deliberately bar the way to human survival?

Marx's writings still have something to teach us about capitalism. They have little or nothing to teach us about any alternatives to it. Anyone who had read them knows that.

I think Fichte did take it further than Kant by arguing that we can regard the moral law as objectively valid only by seeing it as addressed to us by another being, even though Fichte thought God could not literally be a person who could address us.

It is a culturally interesting (but also deeply depressing) fact that many religious claims seem to retain their emotional power for believers only if taken in ways that are intellectually unsupportable and even morally contemptible.

Adam Smith was aware of the way that economic interests could have a distorting and destructive effect both on the market and on politics.

It was an important part of Mendelssohn's philosophical and religious view that the traditional rationalist proofs for God's existence should be sound an convincing. Kant thought they were not. So Kant's critique was world-shaking for Mendelssohn.

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.