Kritik der reinen Vernunft, first edition, in German

According to Wikipedia: "Immanuel Kant (22 April 1724 – 12 February 1804) was an 18th-century German philosopher from the Prussian city of Königsberg (now Kaliningrad, Russia). He is regarded as one of the most influential thinkers of modern Europe and of the late Enlightenment. Kant created a new widespread perspective in philosophy which is influencing enlightened philosophy until the 21st Century. He published important works of epistemology as also scripts in coherence to religion, law and history. His most important work is the Critique of Pure Reason, an investigation into the limitations and structure of reason itself. It encompasses an attack on traditional metaphysics and epistemology, and highlights Kant's own contribution to these areas. The other main works of his maturity are the Critique of Practical Reason, which concentrates on ethics, and the Critique of Judgment, which investigates aesthetics and teleology."