He moved to Athens around 480 BC. Although many great philosophers including Pythagoras had been born in Ionia, the new study of philosophy was alien to Athens.
Anaxagoras introduced the concept of philosophy to Athenians. During his lifetime Socrates, who would one day become a major philosopher himself, was a young boy. Thus Anaxagoras is considered to be an eminent philosopher of the Pre-Socratic period.
Athens at that time was fast developing as the center of Greek culture, and Anaxagoras played a significant role in the scientific and cultural developments of that period.
During his stay in Athens, Pericles rose to power. Pericles was a prominent statesman and general of Athens who had a profound influence on the Athenian society. He took a liking to Anaxagoras and was impressed by his pursuit of scientific enquiry.
Even though Anaxagoras and the would-be philosopher Socrates both lived in Athens, there are no accounts to suggest that the two ever met. However, there are reports that Archelaus, one of the pupils of Anaxagoras later became the teacher of young Socrates.
Anaxagoras brought philosophy to Athens, kindling in the Athenians a love for scientific knowledge and enquiry. He observed the celestial bodies and formed new theories of the universal order.
He tried to explain the scientific reasons behind natural occurrences like eclipses, rainbows and meteors. In fact he gave an amazingly accurate description of why eclipses take place.
During his days, the sun was worshipped as a god. He sought to dispel this belief and claimed that the sun was a mass of red-hot metal. He also correctly told that the stars were similar to the sun but their heat could not be felt on earth due to their enormous distance from the planet.
He was the first philosopher to state that the moon reflects the sun’s light. He was of the belief that there are mountains on the surface of the moon and that it was inhabited.
Anaxagoras was a genius and applied geometry to the study of astronomy. He was among the first individuals to give the correct explanation for the occurrences of eclipses.
He lived for 30 years in Athens, studying and disseminating knowledge. However, his claim that the sun was not a god but a fiery ball of hot metal enraged certain social and political parties and thus he was prosecuted on a charge of impiety.
His long time admirer and friend Pericles spoke in his defense at his trial around 450 BC. Though Pericles managed to save him from a harsher punishment, Anaxagoras was forced to leave Athens.
He had written a book of philosophy, the fragments of which were preserved in the work of Simplicius of Cilicia in the 6th century AD.