Empedocles (490 BC - 430 BC) was a Greek philosopher and a citizen of Agrigentum also known as Acragas, in Sicily.
He maintained that all matter is made up of four classical elements (which he called roots): water, earth, air and fire. In addition to these, he postulated something called Love (philia) to explain the attraction of different forms of matter, and of something called Strife (neikos) to account for their separation. He considered these to be distinct substances, with the four elements in solution with them. This theory was endorsed by Aristotle and remained in place until the Renaissance.
Empedocles was also a mystic and a poet, and some consider him the inventor of the study of rhetoric. Gorgias of Leontini was his student, and it is probably from Empedocles that Gorgias developed the notion of rhetoric as magic.
As a person he was somewhat arrogant, dressing himself in purple and claiming that by the virtue of the knowledge he possessed he had become divine and could perform miracles. Yet his actions and teaching betrayed an egalitarian streak, he fought to preserve Greek democracy and allowed that through his teaching others could also become divine. He even went so far to suggest that all living things were on the same spiritual plane, indicating he was influenced by Pythagorean spirituality.
Empedocles is considered the last Greek philosopher to write in verse and the surviving fragments of his teaching are from his two poems, Purifications and On Nature.