Empedocles lived around 440 BC in Acreages’, on the south coast of Sicily. He was a younger contemporary of Parmenides, though his doctrines were somehow akin to Heraclitus.
In most Greek cities, including Sicily, there was a constant conflict between democracy and tyranny. The leader of whichever party was defeated was executed or exiled. Those exiled seldom scrupled to enter into negotiation with the enemies of Greece-Persia in the east and Carthage in the west. Empedocles who was a democrat didn’t choose any of them after his banishment and rather preferred a life of sage.
Empedocles was a queer mixture of a scientist, a philosopher and a heretic.
Science: His most important contribution to science was his discovery of air as a separate substance. This he proved by the observation that when a bucket or any similar vessel is put upside down into water, the water does not enter into the bucket. He also discovered an example of centrifugal force: that if a cup of water is whirled round at the end of a string, the water does not come out. He had his own theory for evolution and the survival of the fittest. He also believed that moon and sun shines from the reflected light.
Cosmology: He established that the earth, air, fire and water are four basic elements. Each of these is ever lasting and every other thing in this world is a compound of these basic elements. These substances are combined by Love and Strife. Love and Strife are also basic substances along with the four. Period of dominance of love and strife keeps changing. Every compound substance is temporary; only the elements together with love and strife are everlasting.
Empedocles held that the material world is a sphere; that in golden age strife was outside the sphere and love inside and then gradually strife starts entering the sphere and displacing love at worst completely outing it. The process then reverses.
Religion: He had an orphic/Pythagorean view of religion. At times he speaks himself exuberantly as God and at other as a great sinner undergoing expiation for his impiety. It is said that he jumped into the crater of Mount Etna to prove that he is God.