it was all a dream wrote:
My understanding is that modern philosophy is based on the concept that the universe does not exist externally, but rather as a construct of our consciousness. In other words, our consciousness contains the universe, and we can't confirm the independent existence of reality since we have no means of transcending our senses. These are the ideas of Immanuel Kant. But how could our consciousness exist unless we had brains that exist within the physical universe? How could we frame the question if we didn't exist? Is Kant, as Ayn Rand said, the most evil man who ever lived?
You misread Kant's critical project. He was interested in exposing the limits of reason, not in making metaphysical claims about the relation of consciousness to the universe. He would say that any claim about the total nature of the universe is purely speculative and could never be proven because it has no basis in experience. (Read, for example, the section on the antinomies.)
Kant's Critique of Pure Reason was interested in ending these sorts of fantastical, metaphysical questions, which had dominated philosophy during the scholastic period. He wanted to put reason onto what he believed was the task of enlightenment: scientific and experimental conceptual critique. His main goal was to show how the concepts of reason are never sufficient in themselves and always require testing against experience. By the same token, the sense intuitions of experience are meaningless without the application of rational conceptual analysis. This is the upshot of Kantian critique.
As for whether or not Kant was the most evil man who ever lived, I suggest you read a bit more closely and come to your own conclusions on that.