The German philosopher crossword solutions are Georg Wilhelm Friedrich Hegel (5 letters), Immanuel Kant (4 letters), Friedrich Nietzsche (9 letters), Karl Marx (4 letters), and Martin Heidegger (15 letters). Hegel was a 19th century philosopher who developed the concept of dialectical idealism. Kant was an 18th century philosopher who is best known for his work on moral philosophy. Nietzsche was a 19th century philosopher who is known for his critiques of religion and morality. Marx was a 19th century philosopher who developed the theory of historical materialism. Heidegger was a 20th century philosopher who is best known for his work on existentialism.