c.493 - c.435 BC
Empedocles, a philosopher of Greek descent, lived in Sicily.
Empedocles discovered air as a separate substance. In his cosmology fire, air, water and earth mingle and separate under the compulsion of love and strife.
He wrote a poetic treatise 'On Nature'. It contained ideas that anticipated the ideas of evolution, the circulation of the blood, and atmospheric pressure.
Empedocles believed that souls can be reincarnated between humans, animals and plants. All living things were on the same spiritual plane; plants and animals are links in a chain where humans are a link too. Wise people, who have learned the secret of life, are almost divine, and their souls, free from the cycle of reincarnations, are able to rest in happiness for eternity.
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From the Internet Encyclopedia of Philosophy
From the University of St. Andrews, Scotland