Ancient Greek philosopher, mathematician and astronomer, founder of the Athenian school of philosophy.
Country: Greece

  1. Biography of Anaxagoras
  2. Anaxagoras' Philosophy
  3. Contributions to Astronomy
  4. Legacy

Biography of Anaxagoras

Anaxagoras was an ancient Greek philosopher, mathematician, and astronomer, and the founder of the Athenian philosophical school. He was born around 500 BCE in Clazomenae, which is now located in modern-day Turkey, and died in 428 BCE in Lampsacus, also in modern-day Turkey. Anaxagoras developed theories in the fields of mathematics and astronomy. He spent approximately thirty years in Athens and became the practical founder of the Athenian philosophical school. In the late 430s BCE, he was accused of impiety and was forced to emigrate. He spent his last years, from 434-433 BCE, in Lampsacus. Only twenty fragments of Anaxagoras' writings have survived to this day.

Anaxagoras' Philosophy

Anaxagoras' views were influenced by the Milesian school of thought, particularly Anaximenes, as well as Parmenides' teachings on existence. He formulated his philosophy as a cosmogonic hypothesis, according to which the initial state of the world was an immobile and shapeless mixture consisting of countless tiny particles of various substances that were not perceptible to the senses. At a certain moment in time and in a certain region of space, this mixture acquired rapid rotational motion, which was imparted to it by an external agent - the mind or "nous." The cosmic whirlwind, gradually slowing down, is perceived as the rotation of the celestial sphere. Under the influence of the rotational speed, dark, cold, and moist air, which collects in the center of the whirlwind, separates from the bright, hot, and dry Aether, which moves towards its periphery. The particles set in motion strive to combine with similar ones, forming more or less homogeneous masses of substance. However, these masses cannot fully separate because "in everything there is a part of everything," and each thing appears to be what predominates in it. Throughout these transformations, the total quantity of any kind of substance remains unchanged. These principles presumably apply not only to particles of qualitatively homogeneous substances, which in the Peripatetic school were called homoiomeries, but also to the opposites of hot and cold, light and darkness, dryness and moisture.

Contributions to Astronomy

Anaxagoras was the first scholar to provide a correct explanation for solar and lunar eclipses and the first to present a clear theory on the phases of the Moon. He was interested in natural astrology, which refers to the connection between cyclic natural phenomena and the rhythmic movement of celestial bodies. Anticipating modern science by over 2000 years, Anaxagoras taught that stars are made of the same matter as our Earth, and that the Sun is a blazing mass. He believed that the Moon is a dark, uninhabited body that receives its light from the Sun, and that comets are wandering stars or bodies. Diogenes Laërtius, an ancient writer from the 3rd century, reports that Anaxagoras predicted the fall of a stone from the sky. There are also stories about Anaxagoras accurately predicting the collapse of a house. When asked why he was born into the world, Anaxagoras replied, "For the contemplation of the Sun, Moon, and sky."


Anaxagoras' name has been given to a crater near the north pole of the Moon and a minor planet numbered 4180.