1794, from real (adj.) + -ism; after French réalisme or German Realismus; from Late Latin realis "real." Opposed to idealism in philosophy, art, etc. In reference to scholastic doctrine of Thomas Aquinas (opposed to nominalism) it is recorded from 1826. Meaning "close resemblance to the scene" (in art, literature, etc., often with reference to unpleasant details) is attested from 1856.