Empedocles of Acragas

c.492-c.432 B.C.

Sicilian Philosopher, Poet, and Physician

Empedocles is considered, perhaps incorrectly, the originator of the four-element theory of matter that dominated natural philosophy and greatly influenced Western medical thought until the time of the Renaissance.

The facts of Empedocles's life are obscure. He was born at Acragas (later known as Agrigentum, modern Agrigento), on Sicily's southern coast, around 492 B.C. Though born into a wealthy aristocratic family, he championed democratic principles and instigated the overthrow of the tyrannical oligarchy of Acragas known as "the thousand." He was offered the kingship but refused it, preferring instead to continue his study of nature and philosophy. While traveling abroad, his enemies at home raised sufficient support to oppose his return. He spent his remaining years in exile, dying on the Peloponnese around 432 B.C.

Empedocles was greatly influenced by Parmenides of Elea (b. 515 B.C.). He accepted the Parmenidean dictum that nothing can come from nothing and that what exists cannot perish. He also affirmed the Parmenidean denial of a void; but unlike Parmenides, he rejected the further conclusions that reality is a unity and motion impossible. Empedocles's modification of Parmenidean metaphysics and synthesis with previous views and observations generated his now-famous four element theory.

Empedocles maintained that there exists a plurality of primary elements or archai. These were understood to be ungenerated and indestructible as well as qualitatively unalterable and homogeneous. Because matter appears in four forms: vapors (gases), liquids, solids, and fire (associated with aethereal matter), Empedocles thought it plausible that the elements were four in number. Thales (c. 625-c. 547 B.C.) had previously argued that all things were composed of water, Anaximenes (fl. 545 B.C.) air, and Heraclitus (fl. 500 B.C.) fire. To these, Empedocles added earth. He considered them together as the "root" of all things. Accordingly, he argued the characteristics of different substances were determined by the relative mixtures of the four elements.

This plurality allowed Empedocles to explain motion without postulating a void. He taught that the elements continually replace one another, much as one object in a series slides into the place occupied by the object directly before it. Such motion requires no empty spaces.

All modes of change, including generation, corruption, and local motion, were the result of mixing, unmixing, and remixing of the four elements. But because the four were passive,Empedocles believed they could interact only under the influence of Love and Strife—Love being the power of aggregation (attraction) and Strife of separation (repulsion). The same powers that fill men's hearts, Empedocles argued that Love and Strife operate simultaneously but have opposite effects.

The cosmology of Empedocles was cyclical: (1) Under the influence of Love, the four elements fuse into a homogenous sphere; (2) with the gradual ascendancy of Strife, a process of increasing differentiation begins; (3) ultimately, the archai completely separate from one another as the influence of Love wanes; and (4) as Strife then begins to wane and Love increases, a period of progressive integration occurs. Presumably, the cosmos, as we know it, can only exist in stages (2) and (4).

Associated with the homogenous sphere of his cosmic cycle is Empedocles's picture of the universe as a spherical crystalline plenum enclosing Earth. The fixed stars and planets were pockets of fire embedded in this rotating sphere. It is doubtful that he considered Earth itself a sphere. He also correctly explained solar eclipses.

Empedocles was also concerned with zoology and botany. Invoking chance and natural selection, he applied his principles of elemental mixture to the emergence of life. He described earlier life forms and how those best adapted to their environment are able to survive and reproduce. Unlike the later Darwinian theory of evolution, Empedocles's evolutionary mechanism ceases to function precisely when heredity becomes important.

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