Empedocles (c. 490-c. 430 bc), Greek philosopher, statesman, and poet, born in Agrigentum (now Agrigento), Sicily, a disciple of Pythagoras and Parmenides. According to tradition, Empedocles refused to accept the crown offered to him by the people of Agrigentum after he had helped to overthrow the ruling oligarchy. Instead he instituted a democracy.

Modern knowledge of Empedocles's philosophy is based on the surviving fragments of his poems on nature and purification. He asserted that all things are composed of four primal elements: earth, air, fire, and water. Two active and opposing forces, love and hate, or affinity and antipathy, act upon these elements, combining and separating them into infinitely varied forms. According to Empedocles, reality is cyclical. At the beginning of a cycle, the four elements are bound together by the principle of love. When hate penetrates the cycle, the elements begin to separate. Love reunites everything; then hate begins the process once again. The world as we know it is halfway between the primary sphere and the stage of total separation of the elements. Empedocles also believed that no change involving the creation of new matter is possible; only changes in the combinations of the four existing elements may occur. He also formulated a primitive theory of evolution in which he declared that humans and animals evolved from antecedent forms.