Ancient Philosophy

Pre-Socratics

Anaxagoras

The philosopher Anaxagoras, though not to be placed alongside Pythagoras, Heraclitus, or Parmenides, nonetheless stands as a significant historical figure. An Ionian by birth, he continued the scientific rationalist tradition of Ionia and was the first to introduce the Athenians to philosophy, articulating the idea that the mind is the primary cause of physical change.

Anaxagoras was born around 500 BCE in Clazomenae, Ionia, but spent approximately thirty years in Athens (circa 462 to 432 BCE). It is likely that he was invited to Athens by Pericles, who sought to cultivate a more refined culture among his fellow citizens. Perhaps Aspasia, originally from Miletus, introduced Anaxagoras to Pericles. Plato, in his dialogue Phaedrus, remarks: “By associating with Anaxagoras, a man of precisely such a disposition, Pericles was filled with knowledge of the sublime and grasped the nature of the mind and thought, themes often discussed by Anaxagoras; from this, Pericles derived benefits for the art of rhetoric.”

It is said that Anaxagoras influenced Euripides, though this claim is highly contentious. The citizens of Athens, like those in other cities across time and continents, exhibited a certain hostility towards those who sought to instill a higher cultural standard than what they were accustomed to. As Pericles aged, his opponents launched a campaign against him, attacking his friends. They accused Phidias of embezzling a portion of the gold allocated for his statues and enacted a law permitting the prosecution of those who did not adhere to the state religion and propagated various theories about “what lies above.” Under this law, they began to persecute Anaxagoras, accusing him of teaching that the Sun is a heated stone and that the Moon is akin to the Earth. (A similar accusation was later made against Socrates by his pursuers, whom he mocked for their antiquated views.) The specifics of what transpired are unclear; it is only known that Anaxagoras was compelled to leave Athens. It is conceivable that Pericles facilitated Anaxagoras’ escape from prison, allowing him to flee. Anaxagoras returned to Ionia, where he founded a school. According to his will, the anniversary of his death was observed at this school as a day of rest.

Anaxagoras asserted that all things are infinitely divisible and that even the tiniest particle of matter contains a bit of every element. Things are defined by the element that predominates within them; for instance, everything contains some fire, yet we designate as fire only that which contains it in abundance. Like Empedocles, Anaxagoras rejected the notion of a void, arguing that a clepsydra or a blown-up skin demonstrates that where nothing seems to exist, air is present.

He distinguished himself from his predecessors by considering the mind (nous) as a substance that comprises living beings, setting them apart from inanimate matter. He posited that everything contains a part of everything else, except for the mind, and that some things contain the mind as well. The mind possesses authority over all living things; it is infinite and self-governing, mingling with nothingness. Except for the mind, all things, no matter how small, contain elements of all opposites, such as hot and cold, white and black. He even claimed that snow is black (in part).

The mind is the source of all motion, initiating a rotation that gradually extends throughout the cosmos, leading the lightest elements to the periphery while the heaviest descend to the center. The mind is uniform: in animals, it is as good as in humans. The apparent superiority of humans is attributed to their possession of hands; all perceived differences in intellect are, in truth, related to physical disparities.

Both Aristotle and the Socrates of Plato lament that Anaxagoras, despite introducing the concept of the mind, employed it sparingly. Aristotle notes that Anaxagoras introduces the mind as a cause only when he lacks knowledge of another cause. Wherever possible, Anaxagoras provides a mechanical explanation. He dismissed necessity and chance as origins of things. Nonetheless, his cosmology lacks “providence.” He seems to have paid little attention to ethics or religion; it is likely that he was an atheist, as asserted by his persecutors. He was influenced by all his predecessors except for Pythagoras. Parmenides had as much impact on him as he did on Empedocles.

Anaxagoras made significant contributions to science. He was the first to explain that the Moon shines by reflected light, although Parmenides has an embryonic fragment suggesting he may have known this as well. Anaxagoras provided an accurate theory of eclipses and believed that the Moon lies below the Sun. He asserted that the Sun and stars are burning stones, but we do not feel their heat because they are too distant. The Sun, he claimed, is larger than the Peloponnese. He also posited that the Moon has mountains and believed it to be populated.

It is said that Anaxagoras was from the school of Anaximenes; it is certain that he preserved the vibrant rationalist and scientific tradition of the Ionians. His work lacks the predominance of ethics and religion that, from the Pythagoreans to Socrates and from Socrates to Plato, introduced an obscurantist tendency into Greek philosophy. Anaxagoras may not have been in the forefront, but his significance lies in having brought philosophy to Athens and being one of those whose influence contributed to the shaping of Socratic thought.