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History of Science Ancient Egypt

History of Science Online

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LibraryThing: Science in Ancient Mesopotamia Week 3: Ancient Egyptian and Aegean science

Anaxagoras of Klazomenai (fl. 475 B.C.)

| Presocratics Index | Intro | Thales | Anaximandros | Anaximenes | Herakleitos | Parmenides | Zenon | Melissos |
| Atomists: Leukippos and Demokritos | Anaxagoras | Empedokles | Significance of the Presocratics |

From Klazomenai in Asia Minor, one of the twelve cities of Ionia, Anaxagoras moved to Athens around 480 B.C. at the request of Perikles, the great orator and statesman of Athen's democratic golden age. Because he taught that the Sun is a red-hot stone, and that the Moon is made of earth, Anaxagoras was tried by the Athenian citizens on charges of impiety toward the Olympian gods. After thirty years in residence in Athens, during which time he may have taught Socrates, he fled back to Ionia. On this page we shall see that Anaxagoras developed a natural philosophy characterized by a radical pluralism and by teleology.

Radical Pluralism

For Anaxagoras, there are an infinity of elements, and everything consists of a little bit of everything. "In everything there is a portion of everything." All things exist pre-formed in everything in infinitessimal amounts. The seeds of everything are in everything, but the appearances (phenomena) we see are only those things which predominate.

"All things were together, infinite both in number and in smallness; for the small also was infinite. And when they were all together, nothing was clear and distinct because of their smallness; for air and aether comprehended all things, both being infinite; for these are present in everything, and are greatest both as to number and as to greatness." (Fragment 1, Hanover Historical Texts Project)

Anaxagoras was driven to this, the ultimate anti-economy theory, because of the force of Parmenides' argument denying the reality of change: "what is, is; what is not, is not." In contrast to Parmenides, the theory of Anaxagoras does explain apparent change, because things already exist beneath the appearances. (In this respect, there is a striking analogy between the logic of Anaxagoras and theories of preformation in the 18th century.)

17. "The Greeks do not rightly use the terms 'coming into being' and 'perishing.' For nothing comes into being nor yet does anything perish, but there is mixture and separation of things that are. So they would do right in calling the coming into being 'mixture,' and the perishing 'separation.'"
18. "For how could hair come from what is not hair? Or flesh from what is not flesh?"
15. "For neither is there a least of what is small, but there is always a less. For being is not non-being. But there is always a greater than what is great. And it is equal to the small in number; but with reference to itself each thing is both small and great." (Fragments 17, 18 and 15, Hanover Historical Texts Project)

So Anaxagoras’ view easily explained away the question of how change occurs in the face of the challenge posed by Parmenides, but at the expense of an infinity of elements (not an easy idea to accept).


"Teleology" means that something has an intended meaning or end result. For Anaxagoras, nature is inherently teleological. Once he had established that change can occur, then the next question would be, how are changes guided to an orderly result? To explain orderly change in nature, Anaxagoras created a dualism of mind and matter.

"In all things there is a portion of everything except mind; and there are things in which there is mind also." (Fragment 5, Hanover Historical Texts Project)

For Anaxagoras, material elements alone do not explain change. Rather, mind (Nous) organizes matter and intelligently guides the changes that occur naturally. Natural changes occur by intelligent design, as a result of nous, or mind, rather than by chance. (Note that modern advocates of "Intelligent design" employ a line of reasoning that originated outside of Christianity, and that the Nous or intelligent designer for Anaxagoras did not transcend nature, but was a part of nature, in a pagan rather than theistic religious context.)

"Other things include a portion of everything, but mind is infinite and self-powerful and mixed with nothing, but it exists alone itself by itself.... For it is the most rarefied of all things and the purest, and it has all knowledge in regard to everything and the greatest power; over all that has life, both greater and less, mind rules. And mind ruled the rotation of the whole, so that it set it in rotation in the beginning. First it began the rotation from a small beginning, then more and more was included in the motion, and yet more will be included. Both the mixed and the separated and distinct, all things mind recognised. And whatever things were to be, and whatever things were, as many as are now, and whatever things shall be, all these mind arranged in order; and it arranged that rotation, according to which now rotate stars and sun and moon and air and aether, now that they are separated. Rotation itself caused the separation, and the dense is separated from the rare, the warm from the cold, the bright from the dark, the dry from the moist. And there are many portions of many things. Nothing is absolutely separated nor distinct, one thing from another, except mind. All mind is of like character, both the greater and the smaller. But nothing different is like anything else, but in whatever object there are the most, each single object is and was most distinctly these things." (Fragment 6, Hanover Historical Texts Project)

First principle
Thales of Miletos
Anaximandros of Miletos
Anaximenes of Miletos
Herakleitos of Ephesos

Parmenides of Elea,
Zenon of Elea,
Melissos of Samos


Monism, Plenism, Rationalism, Necessitarianism, Sufficient Reason, Akinesis, Eternity of the World

Leukippos of Miletos and Demokritos of Abdera Atoms + Void Pluralism, Void, Tychism
Anaxagoras of Klazomenai
All in All
Radical Pluralism, Teleology


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HSCI 3013. History of Science to 17th centuryCreative Commons license
Kerry Magruder, Instructor, 2004
Brent Purkaple, TA

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Many thanks to the pedagogical model developed in Mythology and Folklore and other online courses by Laura Gibbs, which have been an inspiration for this course.

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