5th-century BC Greek philosopher

Anaxagoras (c. 500 BC – 428 BC) was a Pre-Socratic Greek philosopher from Clazomenae in Asia Minor. He introduced the concept of Nous (Mind), 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.


  • Wrongly do the Greeks suppose that aught begins or ceases to be; for nothing comes into being or is destroyed; but all is an aggregation or secretion of pre-existent things: so that all-becoming might more correctly be called becoming-mixed, and all corruption, becoming-separate.
    • quoted in Heinrich Ritter, Tr. from German by Alexander James William Morrison, The History of Ancient Philosophy, Vol.1 (1838)
  • 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.
  • Thought is something limitless and independent, and has been mixed with no thing but is alone by itself. ... What was mingled with it would have prevented it from having power over anything in the way in which it does. ... For it is the finest of all things and the purest.
    • Frag. B12, in Jonathan Barnes, Early Greek Philosophy (1984), p. 190.
  • 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

  • If one examines the reasons for the persecution of the best minds of different nations, and compares the reasons for the persecution and banishment of Pythagoras, Anaxagoras, Socrates, Plato, and others, one can observe that in each case the accusations and reasons for banishment were almost identical and unfounded. But in the following centuries full exoneration came, as if there had never been any defamation. It would be correct to conclude that such workers were too exalted for the consciousness of their contemporaries, and the sword of the executioner was ever ready to cut off a head held high.... A book should be written about the causes of the persecution of great individuals. By comparing the causes is it possible to trace the evil will.
  • In mathematics... the Greek attitude differed sharply from that of the earlier potamic cultures. The contrast was clear in... Thales and Pythagoras, and it continues to show... in Athens during the Heroic Age. ...while Anaxagoras was in prison he occupied himself with an attempt to square the circle... the first mention of a problem that was to fascinate mathematicians for more than 2000 years. ...Here we see a type of mathematics that is quite unlike that of the Egyptians and Babylonians. It is not the practical application of a science of number... but a theoretical question involving a... distinction between accuracy in approximation and exactitude in thought. more the concern of the technologist than those he raised... concerning the ultimate structure of matter.
  • The big bang and the steady state debate in some ways echoed that between the ideas of Anaximander and Anaxagoras from two and a half millennia earlier. Anaxagoras had envisaged that at one time "all things were together" and that the motive force for the universe originated at a single point... Anaximander on the other hand wanted a universe determined by "the infinite" and needed an "eternal motion" to explain the balancing process of things coming into being and passing away in an eternal universe... ancient philosophy was debating the alternatives of a creation event starting the universe from a single point versus a continuous creation in an eternal universe.
    • David H. Clark & Matthew D. H. Clark, in Measuring the Cosmos: How Scientist Discovered the Dimensions of the Universe (2004)
  • The endless sequence of explanation is explicit in Anaxagoras. Even the ingredients that go to make up something and account for its behaviour are themselves composed of ingredients which are themselves again composed of ingredients. [...] In every case, behaviour is a consequence of both the predominant features (which make it seem to be such and such) and also the hidden features (which can make it do otherwise inexplicable things). And this dual explanation will apply as much to the hidden ingredients as to the macroscopic items we encounter in daily life.

    But still it remains true for Anaxagoras that in principle the material composition (if we could know it in detail) would account for the current behaviour of each item in the world. Unless the thing is alive, that is. For living things, it looks as though the explanation must be supplemented by appeal to another principle, what Anaxagoras called ‘Mind’.

    • Catherine Osborne, Presocratic Philosophy: A Very Short Introduction (2004), Ch. 4 : Reality and appearance: more adventures in metaphysics
  • My dear Meletus, do you think you are prosecuting Anaxagoras? Are you so contemptuous of these men and think them so ignorant of letters as not to know that the books of Anaxagoras of Clazomenae are full of those theories, and further, that the young men learn from me what they can buy from time to time for a drachma, at most, in the bookshops, and ridicule Socrates if he pretends that these theories are his own, especially as they are so absurd? Is that, by Zeus, what you think of me, Meletus, that I do not believe that there are any gods?—That is what I say, that you do not believe in the gods at all.
  • 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.
  • Anaxagoras was more inclined to the study of physics than of metaphysics, for which reason he is accused by Plato and by Aristotle of not having conceded enough to final causes, and of having converted God into a machine. Accordingly he explained on physical principles the formation of plants and animals, and even celestial phenomena; which drew upon him the charge of atheism. Nevertheless, he regarded the testimony of the senses as subjectively true; but as insufficient to attain to objective truth, which was the privilege of the reason.

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Ancient Greek schools of philosophy
Pre-Socratic AnaxagorasAnaximanderAnaximenesDemocritusEmpedoclesHeraclitusLeucippusMelissusParmenidesProtagorasPythagorasThalesZeno of Elea
Socratic AntisthenesAristippusAristotleDiogenes of SinopeEuclid of MegaraPhaedo of ElisPlatoSocrates
Hellenistic Apollonius of TyanaAugustineEpictetusEpicurusJohn PhiloponusLucretiusPlotinusProclusPyrrhoSextus EmpiricusZeno of Citium

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