was a pre-Socratic Greek philosopher who was likely born about 500
BCE (Apollodorus ap. Diog. Laert. ii. 7.). He was a member of what
is now often called the Ionian School of philosophy.
his native town of Clazomenae in Asia Minor, he appears to have
had some amount of property and prospects of political influence;
he supposedly surrendered both of these out of a fear that they
would hinder his search for knowledge. Although a Greek, he was
probably a Persian citizen, perhaps even a soldier of the Persian
army since Clazomenae was suppressed during the Ionian Revolt.
early manhood (c. 464-462 BCE) he went to Athens, which was rapidly
becoming the centre of Greek culture. There he is said to have
remained for thirty years. Pericles learned to love and admire
him, and the poet Euripides derived from him an enthusiasm for
science and humanity. Some authorities assert that even Socrates
was among his disciples.
brought philosophy and the spirit of scientific inquiry from Ionia
to Athens. His observations of the celestial bodies led him to
form new theories of the universal order; he attempted to give
a scientific account of eclipses, meteors, rainbows and the sun,
which he described as a mass of blazing metal, larger than the
Peloponnesus. The heavenly bodies, he asserted, were masses of
stone torn from the earth and ignited by rapid rotation. However,
these theories brought him into collision with the popular faith.
was arrested by his friend Pericles' political opponents on a
charge of contravening the established dogmas of religion (some
say the charge was one of Medism), and it required all the eloquence
of Pericles to secure his release. Even so he was forced to retire
from Athens to Lampsacus in Ionia (434-433 BCE), where he died
about 428 BCE. Citizens of Lampsacus erected an altar to Mind
and Truth in his memory, and observed the anniversary of his death
for many years afterward.
wrote a book of philosophy, but only fragments of the first part
of this have survived through the preservation of Simplicius of
Cilicia (6th century CE).