Anaxagoras (; , Anaxagóras, "lord of the assembly"; 500 – 428 BC) was a Pre-Socratic Greek philosopher. Born in Clazomenae at a time when Asia Minor was under the control of the Persian Empire, Anaxagoras came to Athens. According to Diogenes Laërtius and Plutarch, in later life he was charged with impiety and went into exile in Lampsacus; the charges may have been political, owing to his association with Pericles, if they were not fabricated by later ancient biographers. Responding to the claims of Parmenides on the impossibility of change, Anaxagoras introduced the concept of Nous (Cosmic Mind) as an ordering force. He also gave several novel scientific accounts of natural phenomena, including the notion of panspermia, that life exists throughout the universe and could be distributed everywhere. He deduced a correct explanation for eclipses and described the Sun as a fiery mass larger than the Peloponnese, as well as attempting to explain rainbows and meteors. Biography Anaxagoras was born in the town of Clazomenae in the early 5th century BCE, where he may have been born into an aristocratic family. He arrived at Athens, either shortly after the Persian war, which he may have fought in on the Persian side, or sometimes when he was a bit older, around 456 BCE. While at Athens, he became close with the Athenian statesman Pericles According to Diogenes Laërtius and Plutarch, in later life he was charged with impiety and went into exile in Lampsacus; the charges may have been political, owing to his association with Pericles, if they were not fabricated by later ancient biographers. According to Laërtius, Pericles spoke in defense of Anaxagoras at his trial, Even so, Anaxagoras was forced to retire from Athens to Lampsacus in Troad (433). He died there in around the year 428. Citizens of Lampsacus erected an altar to Mind and Truth in his memory and observed the anniversary of his death for many years. They placed over his grave the following inscription: Here Anaxagoras, who in his quest of truth scaled heaven itself, is laid to rest. Philosophy Responding to the claims of Parmenides on the impossibility of change, Anaxagoras described the world as a mixture of primary imperishable ingredients, where material variation was never caused by an absolute presence of a particular ingredient, but rather by its relative preponderance over the other ingredients; in his words, "each one is... most manifestly those