Vaihinger Hans (1852–1933), German philosopher best known for Die Philosophie des Als Ob (1911; translated by C. K. Ogden as The Philosophy of ‘As If’ in 1924). A neo-Kantian, he was also influenced by Schopenhauer and Nietzsche. His commentary on Kant’s Critique of Pure Reason (2 vols., 1881) is still a standard work. Vaihinger was a cofounder of both the Kant Society and Kant-Studien. The ‘philosophy of the as if’ involves the claim that values and ideals amount only to ‘fictions’ that serve ‘life’ even if they are irrational. We must act ‘as if’ they were true because they have biological utility. M.K.