Jakob Friedrich Fries

Jakob Friedrich Fries (1773 to 1843) was a German post-Kantian philosopher and mathematician. He studied theology at the Moravian academy at Niesky and philosophy at Leipzig and Jena, and became professor of philosophy and elementary mathematics at Heidelberg in 1806. His main philosophical work, the New or Anthropological Critique of Reason, tried to give Kant's critical philosophy a psychological foundation, and he also published a System der Logik in 1811. Called to Jena in 1816 for theoretical philosophy, including mathematics and physics, he was a liberal nationalist who influenced the Burschenschaft student movement. After the Carlsbad Decrees he lost his chair, but the Grand Duke of Weimar kept paying his stipend, and in 1824 he returned to Jena as professor of mathematics and physics, with full lecturing rights restored in 1838. He quarrelled publicly with Hegel, and the article records that he wrote antisemitic polemics, including a 1816 pamphlet advocating a distinguishing sign on Jewish dress and encouraging emigration, a harmful part of his legacy.