Anaxagoras: History, Achievements & Facts

Anaxagoras – Biography, Philosophy and Contribution to Astronomy
Generally regarded as one of the most distinguished Pre-Socratic philosophers of ancient Greece, Anaxagoras of Clazomenae is best known for his physical theory of the universe that states that a part of every thing can be found in every thing. According to the Clazomenae-born philosopher, the mind or intellect (i.e. nous) is what gave birth to the universe. Based on his doctrine of nous (mind or reason), he opined that the power of the mind can influence the growth of living things.
A renowned cosmologist of his era, Anaxagoras is also credited with being the first to produce a correct explanation of how eclipses occur. His scientific investigations allowed him to come out with some scientific theories about the sun, the moon, rainbows, meteors, and stars. On the latter, he stated that they were fiery stones.
Anaxagoras: Fast Facts
Born: c. 500 b.c.
Place of birth: Clazomenae, Anatolia (modern day Turkey)
Died: c. 428 b.c.
Place of death: Lampsacus
Father: Hegesibulus
Areas of interest: Natural philosophy, including cosmology, astronomy, and philosophy
School: Pluralist
Most known for: discovering the real cause of eclipses
Association: Pericles
Most famous theory: the theory of “everything-in-everything”
Influenced: Pericles, Socrates, Protagoras
Early life and time in Clazomenae
Anaxagoras was born and grew up in Clazomenae in Anatolia (what is now present day Turkey). He came from a family of moderately wealthy aristocrats. Rather than continue in his family’s tradition, he chose to pursue philosophy.
He grew up in a time when the Persian Empire held vast control of Asia Minor (i.e. the majority of modern-day Turkey). This meant that at one point in his life he served in the Persian army, probably fought alongside Persian forces during the Greco-Persian Wars (499 B.C. – 449 B.C.).
Athens’ first Pre-Socratic Philosopher

Anaxagoras influenced many philosophers and thinkers of ancient Greece, including Pericles (left) and Socrates
Following his decision to study philosophy, Anaxagoras relocated from Ionia to Athens in the mid-5th century. In Athens, he became friends with an up and coming Athenian statesman known by the name of Pericles. It’s been said that the two developed a strong bond, with Anaxagoras acting as the mentor/teacher of Pericles.
He spent more than two decades living in Athens. In that time he is said to have tutored the Greek poet Euripides in a host of scientific inquiries and other philosophical reasoning.
Philosophy and scientific works of Anaxagoras of Clazomenae
Anaxagoras had a heightened passion for using scientific method to understand nature, astronomy, meteors, and rainbow. From his studies of the physical universe, including celestial bodies, he came up with new theories to explain the ingredients of the cosmos (More on this below).
Regarding his studies of meteors, the philosopher and scientist is said to have come out with a technique to measure the impact of meteorites. Some later commentators stated that he predicted the fall of a meteorite in the mid-5th century B.C.
As part of his studies of celestial bodies, he delved into the nature of eclipses, working very hard to correctly explain how they occur. He thus became the first-known scientist who came close to properly explaining how eclipses come about. His understanding of celestial bodies in the sky was enriched by the observations he made of the eclipse of 463 B.C.
Anaxagoras rightly predicted the presence of mountains on the Moon. However, he believed that the Moon was inhabited.
According to Anaxagoras, the celestial bodies were made of large chunks of stone that broke away from the Earth.
Although stated in the mid-5th century B.C., Anaxagoras’ claim that the Sun is made up of red-hot metal comes close to our modern understanding of the body. Similarly, his scientific inquiries led him to believe that the stars are made of very hot stones.
He explained the occurrence of earthquake as the result of a disturbance to the field of air that held the earth floating. He believed the earth is flat.
Anaxagoras on trial for impiety (godlessness)
Anaxagoras unrelenting scientific inquiries into celestial bodies resulted in him getting charged of asebeia, the lack of reverence towards divine objects or the gods
While in Athens, his scientific theories and philosophies got him in hot waters. Anaxagoras was charged with impiety after he stated that the Sun is an incandescent stone which is larger than the Peloponnese region in southern Greece. It’s been said that Anaxagoras rejected the existence of a solar god or lunar god.
The charges against Anaxagoras were brought by Cleon, a warmongering Athenian general and statesman. Athenian statesman and pro-democracy politician Pericles stood in defense of his former tutor during the trial.
Some accounts state that the charges brought against him were anything but political. Anaxagoras’s political views took conciliatory tone towards the Persians, one of the Athens’ fiercest rivals. In any case, the philosopher found himself having to go into exile around 437 B.C.
Some historians opine that the charges brought against Anaxagoras were politically inspired by foes of Pericles, particularly Cleon who had convinced many Athenians that Anaxagoras was to blame for the Peloponnesian War (431 – 404 BC).

Anaxagoras claim that the sun was made up of red-hot metal landed him in hot waters with some sections of Athenian society. | Anaxagoras’ quote
Years in exile and death
With the help of Pericles, Anaxagoras was able to flee Athens and head to Lampsacus in northern Troad (present day Canakkale province, Turkey).
He spent his later years in relative obscurity. About 5 years into his exile in Lampsacus, he died. The town where he lived built an altar to honor his contributions and memory, praising him for his studies on the mind as well as his quest of truth.
Anaxagoras’ influence on Socrates
Even though Anaxagoras lived in Athens during Socrates rise to prominence, there exist no evidence to suggest that the two philosophers interacted with each other.
According to Diogenes Laeritius, Anaxagoras’ pupil Archelaus served as the tutor of Socrates.
According to Plato’s Apology and Phaedo, Socrates cites Anaxagoras as having a big influence on him. In Plato’s Phaedo, for example, Socrates tells his accusers (during his trial) that he was a big admirer of Anaxagora’s books and works.
Typical of many works by Pre-Socratic philosophers, Anaxagoras’s works exist in bits and pieces. Much of what we know about his philosophy and scientific methods is kind courtesy to the writings of philosophers and historians that came after him.
Anaxagoras’ notions on the ingredients of the cosmos

According to the Greek philosopher Anaxagoras, “a part of every thing can be found in every thing”. Painting of Anaxagoras; part of a fresco in the portico of the National University of Athens.
His notions on the universe and what constituted it received critical praise from many later philosophers and commentators. He stated that things in the universe are made of an infinite number of homogeneous ingredients as well as heterogeneous ingredients.
His studies of the physical universe led him to the conclusion that it was made of a single fundamental element with an infinite number of ingredients. Unlike his predecessors who stated that the universe was made of basic substance and elements like heat or water, Anaxagoras opined that “everything is in everything”.
The 6th-century C.E. neo-Platonist commentator Simplicius stated that in Anaxagoras believed that the ingredients are forever and are continuously mixed with everything.

Anaxagoras stated that every ingredient of the cosmos is ubiquitous. He added that some ingredients come in higher concentrations than others. Anaxagoras held the view that the power of the mind can influence the growth of living things.
Anaxagoras and the doctrine of nous (mind or reason)
Anaxagoras believed that the universe came from mind – in two stages. The first stage witnessed the revolving and mixing process of the universe’s ingredients.
The second stage was characterized by the development of living things. After that all the dark joined to bring forth the night. Subsequently, fluid came together to form oceans. In other words, similar things joined together.
Read More: Top 10 Great Philosophers of Ancient Greece
More Anaxagoras Facts

To Anaxagoras, the Cosmos is a vast mixture of all ingredients. He goes further to say that no individual ingredient stands out as they are all thoroughly mixed. | Image: Anaxagoras, depicted as a medieval scholar in the Nuremberg Chronicle
- He is credited with writing a book; however, not much of the book remains. Kind courtesy to the writings of the 6th-century philosopher Simplicius of Cilicia, we know a bit more about the works and contributions of Anaxagoras.
- Because only small parts of his writings were preserved, our understanding of the scientific theories of Anaxagoras is furthered by later interpretations of the philosopher’s works.
- Aristotle, the famous Greek polymath and tutor of Alexander the Great, was of immense praise of Anaxagoras.