Anaxagoras (c. 500 BC – 428 BC) was a Presocratic Greek philosopher, from Clazomenae in Asia Minor. He introduced the concept of Mind (Nous), as an ordering force in the cosmos. He regarded material substance as an infinite multitude of imperishable primary elements, referring all generation and disappearance to mixture and separation respectively.
- All things were together, infinite both in number and in smallness; for the small too was infinite.
- Frag. B 1, quoted in John Burnet's Early Greek Philosophy, (1920), Chapter 6.
- And since these things are so, we must suppose that there are contained many things and of all sorts in the things that are uniting, seeds of all things, with all sorts of shapes and colours and savours
- Frag. B 4, quoted in John Burnet's Early Greek Philosophy, (1920), Chapter 6.
- Mind is infinite and self-ruled, and is mixed with nothing, but is alone itself by itself.
- Frag. B 12, quoted in John Burnet's Early Greek Philosophy, (1920), Chapter 6.
- The Greeks follow a wrong usage in speaking of coming into being and passing away; for nothing comes into being or passes away, but there is mingling and separation of things that are. So they would be right to call coming into being mixture, and passing away separation.
- Frag. B 17, quoted in John Burnet's Early Greek Philosophy, (1920), Chapter 6.
- The sun provides the moon with its brightness.
- Fragment in Plutarch De facie in orbe lunae, 929b, as quoted in The Riverside Dictionary of Biography (2005), p. 23
Quotes about Anaxagoras 
- Anaxagoras held that everything is infinitely divisible, and that even the smallest portion of matter contains some of each element. Things appear to be that of which they contain the most. Thus, for example, everything contains some fire, but we only call it fire if that element preponderates. He argues against the void, saying that the clepsydra or an inflated skin shows that there is air where there seems to be nothing.
- In science [Anaxagoras] had great merit. It was he who first explained that the moon shines by reflected light... Anaxagoras gave the correct theory of eclipses, and knew that the moon was below the sun. The sun and stars, he said, are fiery stones, but we do not feel the heat of the stars because they are too distant. The sun is larger than the Peloponnesus. The moon has mountains, and (he thought) inhabitants.
- Bertrand Russell, Ibid., p. 63