The Critique of Pure Reason — Immanuel Kant

The Critique of Pure Reason (German: Kritik der reinen Vernunft), first published in 1781, with a second edition in 1787, is the most widely read work of the German philosopher Immanuel Kant, and is widely regarded as one of the most influential works in the history of philosophy. It is often referred to as Kant's "first critique," and was followed by the Critique of Practical Reason and the Critique of Judgement.

-- Excerpted from Wikipedia, the free encyclopedia.