[Tim1776]

If you study this a little deeper, you will discover that it is improper to cast Kant in the role of being a champion of reason.

On the contrary, Kant made no secret of his motive for writing those books. His aim was to make a metaphysical domain for religion.

His method was to drive a wedge between the natural world and the human mind.

In the Preface to the Second Edition of the "Critique of Pure Reason", he says "I must, therefore, abolish knowledge, to make room for belief."

To understand Kant's main gimmick, see "Introduction to Objectivist Epistemology" by Ayn Rand.

[gjm11]

Kant did indeed write the words you quote. But I wonder whether you've actually read them in their context, because it seems very obvious to me that he is applying this statement only to metaphysics. He is saying that we cannot know for certain (for instance) whether God exists, or whether "free will" is real. Now, this may be right or wrong, but it certainly isn't anti-rational.

As for the "wedge between the natural world and the human mind": if by that you mean that, e.g., he insisted that our minds aren't presented directly with Things Themselves, and that perception is an indirect affair: yup, he did, and he was right, and again I see nothing anti-rational in that. (Yes, I know Objectivism teaches otherwise. So much the worse for Objectivism.)

[Tim1776]

It is anti-rational to try to establish a premise for reasoning by arbitrary assertion. In other words, an evidence-free reason is no reason at all.

Simply stating a position in order to propel a line of thought is just empty talk, to be dismissed without further consideration.