Immanuel Kant
Kant published a second edition of the "Critique of Pure Reason" ("Kritik der reinen Vernunft") in 1787, heavily revising the first parts of the book. Most of his subsequent work focused on other areas of philosophy. He continued to develop his moral philosophy, notably in 1788's "Critique of Practical Reason" (known as the second "Critique") and 1797's "Metaphysics of Morals". The 1790 "Critique of Judgment" (the third "Critique") applied the Kantian system to aesthetics and teleology. It was in this critique where Kant wrote one of his most popular statements, ""it is absurd to hope that another Newton will arise in the future who will make comprehensible to us the production of a blade of grass according to natural laws"".
Immanuel Kant
Kant defines his theory of perception in his influential 1781 work the "Critique of Pure Reason", which has often been cited as the most significant volume of metaphysics and epistemology in modern philosophy. Kant maintains that our understanding of the external world had its foundations not merely in experience, but in both experience and "a priori" concepts, thus offering a "non-empiricist critique of rationalist philosophy", which is what has been referred to as his Copernican revolution.