Kantianism

In 1781, Kant, in his Critique of Pure Reason, delivered the bad news that the human mind can (even worse, must) pose important, unavoidable philosophical questions that it cannot possibly answer. These were distinct, perennial philosophical questions answerable, if at all, by pure reason alone, independent of any appeal to experience. (Kant thought the most important ones concerned freedom, the existence of God, and the immortality of the soul, but the scope of his critique also extended to issues such as the nature of the mind, the human good, the purpose of nature, or any attempt to know “things in themselves.”) While, according to Kant, we could at least settle once and for all just what those limits to knowledge were and why we were not able to cross such a boundary, that seemed small consolation. Metaphysics, the “queen of the sciences,” had understood itself as capable of knowing how things must be or could not be, and so had prided itself on the certainty of its claims and on a rigor in its method rivaled only by mathematics. So it was not for nothing that Kant became known as the “all-destroying.”

The skeptical sentiment expressed in Kant's critical work was not, of course, isolated in Königsberg. The latter half of the eighteenth century can be viewed as a collective debate about the nature and even future of rationalist philosophy, or philosophy as it had come to be understood since Plato (especially as the impact and advances of Newtonian physics were more and more felt) and about the right way to state the principles underlying an ever more popular empiricism.