1. in philosophy, the doctrine that reality consists solely of natural objects and that therefore the methods of natural science offer the only reliable means to knowledge and understanding of reality. Naturalism is closely related to physicalism and materialism and explicitly opposes any form of supernaturalism or mysticism that posits the existence of realities beyond the natural and material world.

2. in literature and the other arts, a movement that developed in the late 19th century, often seen as arising out of realism, the literary movement and style that generally preceded it. Naturalistic writers aimed to depict life without idealistic illusions or literary artifice and often chose challenging or taboo subjects, such as divorce or prostitution. The plays and novels often show a strong leaning toward psychological determinism, with the behavior of the characters being explained in terms of their heredity or environment. Leading exponents of naturalism included French writers Émile Zola (1840–1902), Alphonse Daudet (1840–1897), and Guy de Maupassant (1850–1893), Norwegian dramatist Henrik Ibsen (1828–1906), and German dramatist Gerhart Hauptmann (1862–1946). See also positivism. —naturalistic adj.