Empedocles of Acragas (c. 495-435 BC) was a Greek scientist and philosopher known for his new physical, chemical, and biological insights that influenced later philosophers such as Plato and Aristotle. Empedocles proposed a theory of elements based on the essential four: air, fire, earth, and water. These elements foreshadowed later developments in atomic theory by philosophers such as Leucippus and Democritus. Empedocles postulated 'Love' (philia) to explain the attraction of different forms of matter, and 'Strife' (neikos) to account for their separation.
Empedocles - Biography (University of Tennessee at Martin, Internet Encyclopedia of Philosophy)
Empedocles of Acragas - Biography (University of St. Andrews, Scotland, School of Mathematics and Statistics)