Crusius, Christian August (1715–75)

Crusius was a pivotal figure in the middle period of the German Enlightenment, linking Pufendorf and Thomasius with Kant. Though sometimes wrongly characterized (for example, by Hegel) as a Wolffian, he was instead an important critic of that position. His system reflected a new alliance between Pietism and Lutheran orthodoxy, offering a comprehensive antirationalist, realist, and voluntarist alternative to the neoscholastic tradition as renovated by Leibniz. Crusius was important in Kant’s development and helps us understand the latter’s philosophical Protestantism.

Born a pastor’s son in Leuna bei Merseburg, in Saxony, Crusius was educated at Leipzig and much influenced there by the Thomasian professor A.F. Hoffmann (1703–41). Interested in both philosophy and theology throughout his career, he accepted a chair as extraordinary professor of philosophy at Leipzig in 1744. In 1750, however, he became ordinary professor of theology, also retaining his teaching post in philosophy until his death. His reputation as a philosopher peaked in Germany during the 1750s and 1760s, mainly on the basis of four scholastic manuals published in German during 1744–9. His greater theological reputation as founder of a ‘biblico-prophetic’ school emphasizing the inspirational unity of Scripture lasted well into the mid-nineteenth century.