Editing Anaxagoras (section)

==Philosophy==
Responding to the claims of [[Parmenides]] on the impossibility of change, Anaxagoras described the world as a mixture of primary imperishable ingredients, where material variation was never caused by an absolute presence of a particular ingredient, but rather by its relative preponderance over the other ingredients; in his words, "each one is... most manifestly those things of which there are the most in it".{{sfn|Curd|2011|loc=B12}} He introduced the concept of ''[[nous]]'' ([[Cosmos|cosmic]] mind) as an ordering force, which moved and separated the original mixture, which was [[homogeneous]] or nearly so.

Anaxagoras brought philosophy and the spirit of scientific inquiry from [[Ionia]] to Athens. According to Anaxagoras, all things have existed in some way from the beginning, but originally they existed in infinitesimally small fragments of themselves, endless in number and inextricably combined throughout the universe. All things existed in this mass but in a confused and indistinguishable form.{{sfn|Wallace|Mitchell|1911|p=943}} There was an infinite number of homogeneous parts ({{lang|el|ὁμοιομερῆ}}) as well as heterogeneous ones.{{sfn|Wallace|Mitchell|1911|p=943}}{{sfn|Schmitz|1870}}

The work of arrangement, the segregation of like from unlike, and the summation of the whole into totals of the same name, was the work of [[Nous|Mind or Reason]] ({{lang|el|νοῦς}}). Mind is no less unlimited than the chaotic mass, but it stood pure and independent, a thing of finer texture, alike in all its manifestations and everywhere the same. This subtle agent, possessed of all knowledge and power, is especially seen ruling all life forms.{{efn|B12}} Its first appearance, and the only manifestation of it which Anaxagoras describes, is Motion. It gave distinctness and reality to the aggregates of like parts.{{sfn|Wallace|Mitchell|1911|p=943}}

Decrease and growth represent a new aggregation ({{lang|el|σὐγκρισις}}) and disruption ({{lang|el|διάκρισις}}). However, the original intermixture of things is never wholly overcome.{{sfn|Wallace|Mitchell|1911|p=943}} Each thing contains parts of other things or heterogeneous elements, and is what it is only on account of the preponderance of certain homogeneous parts which constitute its character.{{sfn|Smith|1952}} Out of this process arise the things we see in this world.{{sfn|Smith|1952}}

=== Astronomy ===
Plutarch{{efn|Life of Lysander 12.1}} says "Anaxagoras is said to have predicted that if the heavenly bodies should be loosened by some slip or shake, one of them might be torn away, and might plunge and fall to earth." 

His observations of the celestial bodies and the fall of [[meteorite]]s led him to form new theories of the universal order, and to the prediction of the impact of meteorites. According to Pliny{{efn|Natural History 2.149}}, he was credited with predicting the fall of the [[Aegospotami|meteorite in 467]].{{sfn|Couprie|2004}} He was the first to give a correct explanation of eclipses, and was both famous and notorious for his scientific theories, including the claims that the Sun is a mass of red-hot metal, that the Moon is earthy, and that the stars are fiery stones.{{efn|Curd|2007}} He thought that the Earth was flat and floated supported by 'strong' air under it, and that disturbances in this air sometimes caused earthquakes.{{efn|Burnet|1892}} He introduced the notion of [[Panspermia#History|panspermia]], that life exists throughout the universe and could be distributed everywhere.{{sfn|Hollinger|2016}}{{sfn|Kolb|Clark|2020|p=47}}

He attempted to give a scientific account of [[eclipse]]s, [[meteor]]s, [[rainbow]]s, and the [[Sun]], which he described as a mass of blazing metal, larger than the [[Peloponnese]]; he also said that the Moon had mountains, and he believed that it was inhabited. The heavenly bodies, he asserted, were masses of stone torn from the Earth and ignited by rapid rotation.{{sfn|Wallace|Mitchell|1911|p=943}} His theories about eclipses, the Sun, and Moon may well have been based on observations of the eclipse of 463 BC,{{efn|{{Cite web | url=https://eclipse.gsfc.nasa.gov/SEsearch/SEsearchmap.php?Ecl=-04620430 |title = NASA - Total Solar Eclipse of -462 April 30}}}} which was visible in Greece.

Anaxagoras was one of the first to assert that the Moon reflected [[sunlight]] and did not produce light by itself; a statement translated as “the sun induces the moon with brightness” was found in his writings.<ref>{{Cite book |last=Burgess |first=Mark Robert |url=https://books.google.com/books?id=vUF_6_BYYuUC&pg=PP1 |title=Transcendent Apriorism: Pure Reason's Quest for the Noumenal |year=2011 |pages=90 |publisher=Universal-Publishers |isbn=9781599423814 |language=en}}</ref>

===Mathematics===
According to [[Plutarch]] in his work ''On exile'', Anaxagoras is the first Greek to attempt the problem of [[squaring the circle]], a problem he worked on while in prison.{{efn|Plutarch, On exile}}