Euhemerism

Euhemerism (from Echemerus, a Sicilian and Cyrenaic philosopher of the 4th century B.C.), a system of explaining the ancient myths of the Greek gods by looking at them all as deified heroes, whose real deeds viewed through the mist of time became distorted and exaggerated. Euhemerus himself had a vivid imagination, and was looked on as a great liar. The tracing of the religious sentiment to totemism and ancestor worship is a kind of Euhemerism.