18th-century philosophers 19th-century German non-fiction writers 19th-century German male writers 19th-century German writers 19th-century German philosophers 19th-century philosophers Academic staff of the University of Rostock Continental philosophers Epistemologists German idealism German male non-fiction writers Idealists Kantian philosophers Kantianism Lecturers Metaphilosophers Writers from Gdańsk People from Royal Prussia Phenomenologists Philosophers of education Philosophers of language Philosophers of mind Academic staff of the University of Halle University of Königsberg alumni