Tetens Johann Nicolas (1736–1807), German philosopher and psychologist, sometimes called the German Locke. After his studies in Rostock and Copenhagen, he taught at Bützow and Kiel (until 1789). He had a second successful career as a public servant in Denmark (1790–1807) that did not leave him time for philosophical work. Tetens was one of the most important German philosophers between Wolff and Kant. Like Kant, whom he significantly influenced, Tetens attempted to find a middle way between empiricism and rationalism. His most important work, the Philosophische Versuche über die menschliche Natur und ihre Entwicklung (‘Philosophical Essays on Human Nature and its Development,’ 1777), is indicative of the state of philosophical discussion in Germany before Kant’s Critique of Pure Reason. Tetens, who followed the ‘psychological method’ of Locke, tended toward a naturalism, like that of Hume. However, Tetens made a more radical distinction between reason and sensation than Hume allowed and attempted to show how basic rational principles guarantee the objectivity of human knowledge. M.K.