Dietrich**, a laborious if not a profound philosopher, was born near Bremen on the 3d of April 1748. He early displayed a love of letters at the Atheneum of Bremen, and, on his entering the university of Göttingen, he read classics and philosophy rather than theology. Jurisprudence fared no better, and he resolved at last to pursue his own inclinations. This last act having cut off his resources, after spending some years as a tutor, his friend Heyne obtained for him a professorship of ancient literature in Cassel. He was removed to Marburg in 1786, where he lectured on almost every subject connected with history, literature, and philosophy. As a philosopher he is obscure, and deficient in depth and accuracy. Tiedemann has written many works, of which the best known is his *Geist der Speculativeen Philosophie*, 6 vols., 1791-97.