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"".
Joseph Green (merchant)
Around 1764 Green met Kant and became a close member of his circle of friends. Kant went often to Green's house outside of Königsberg in Juditten. Green shared with Kant a deep appreciation of the ideas of David Hume and Jean-Jaques Rousseau, in addition, Green could provide as perspective of the outside world that was helpful for Kant. Meeting on a regular basis, Kant discussed his work with him, so every sentence of his "Critique of Pure Reason" prior to the 1781 publication. Kant also entrusted Green with his money.