The Critique of Pure Reason was a critique of the pretensions of pure theoretical reason to attain metaphysical truths beyond the ken of applied theoretical reason. Its conclusion was that pure theoretical reason must be restrained, because it produces confused arguments when applied outside its sphere.
Immanuel Kant (April 1724 – 12 February 1804) was a German philosopher and one of the central Enlightenment thinkers.[25][26] Born in Königsberg, Kant's comprehensive and systematic works in epistemology, metaphysics, ethics, and aesthetics have made him an influential figure in modern Western philosophy.