Greek philosopher of the 5th century. He was born in Clazomene (Ionia). His work of nature, just some fragments have reached us. Connoisseur of the doctrines of Anaximenes, Zeno and Parmenides, Empedocles, travelled to Athens already being famous for their original doctrines. He was master and friend of Pericles, so when this was pursued, Anaxagoras also suffered the consequences, being accused of asebeia (impiety), which had to flee from Athens.
Anaxagoras accepts the theory of the immutability of the self, following in this the thought of Empedocles. But strives to reconcile the two trends: the immobility of the self and the eternal becoming. If Empedocles explained the creation of beings from the quantitative point of view (based on the four elements), Anaxagoras will make it appealing to the qualitative aspect. Four non-constituent particles, but infinite. It is in every thing there are many germs (spermata) qualitatively different. Anaxagoras wondered how could emerge the decreasing hair, for example. Comes to the conclusion that something emerging out must be before present in that which comes from. I.e.: thus arrives at the beginning everything is in everything. We have here a precursor doctrine of the theory of atoms.
But the great contribution of Anaxagoras to the philosophical thought, is to have introduced in the explanation of the universe the nous, a driving force behind all that exists. The entity of the nous is such that is above any other reality. The nous "is infinite and autonomous, and with no mixing", and all things are impregnated with it. Well Aristotle warns: "When he said that there is a mind, both human beings and nature, appeared a wise man among the desatinados that preceded it". But Anaxogoras did not carry its discovery to its: stayed there, without ascribing any final cause in the causation of the nous. And this is what neglect you both Aristotle and Plato. On the other hand, the nous, although it is a matter of subtle and pure, in Anaxagoras not becomes immaterial. And is that it was still far the distinction between matter and spirit. However, it is fair to give it an important position in the development of Greek monotheism.
Anaxagoras gave a great impetus to the investigation of nature founded in experience, memory and technique. They are attributed to the rational explanations of eclipses and the respiration of fish such as also research on the anatomy of the brain.