Empedocles (c. 494 – c. 434 BC, fl. 444–443 BC) was a Greek pre-Socratic philosopher and a native citizen of Akragas, a Greek city in Sicily. Empedocles' philosophy is best known for originating the cosmogonic theory of the four classical elements.

He assumed that all matter was composed of four essential ingredients, fire, air, water, and earth, and that nothing either comes into being or is destroyed but that things are merely transformed, depending on the ratio of basic substances, to one another.

Like Heracleitus, he believed that two forces, Love and Strife, interact to bring together and to separate the four substances. Strife makes each of these elements withdraw itself from the others; Love makes them mingle together. The real world is at a stage in which neither force dominates.

In the beginning, Love was dominant and all four substances were mixed together; during the formation of the cosmos, Strife entered to separate air, fire, earth, and water from one another. Subsequently, the four elements were again arranged in partial combinations in certain places; springs and volcanoes, for example, show the presence of both water and fire in the Earth.

About a century after Empedocles devised it, Aristotle popularized and added to it.

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