Reason necessarily expresses itself through emotions and emotions are healthy only insofar as they are expressions of reason.

Capitalism has proven to be a far more terrible system than Marx could ever bring himself to imagine. Those who are so deluded as to find something good in it, or even feel loyalty toward it, are its most pitiful victims.

Many who are committed to reason and science have turned against religion altogether and treat it with fear and contempt.

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.

I think the term "Kantian constructivism" as an oxymoron. Kant was a constructivist about mathematics, but not about ethics.

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.

Fichte would identify all states of our minds with states of our body - perhaps not merely of our brain, but the whole body as an acting organism.