Anaxagoras

1. Anaxagoras

Anaxagoras (Greek: Ἀναξαγόρας, lord of the assembly; c.  500- c.  428 BC) was a Pre-Socratic Greek philosopher.

Born in Klazomenai (now Urla near Izmir in Turkey), later at a time when Asia Minor was under the control of the Persian Empire, Anaxagoras came to Athens.

According to Diogenes Laertius and Plutarch, in later life he was charged with impiety and went into exile in Lampsacus; the charges may have been political, owing to his association with Pericles, if they were not fabricated by later ancient biographers.

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.

He introduced the concept of Nous (Cosmic Mind) as an ordering force, which moved and separated out the original mixture, which was homogeneous, or nearly so.

He also gave a number of novel scientific accounts of natural phenomena:

He deduced a correct explanation for eclipses and described the Sun as a fiery mass larger than the Peloponnese, as well as attempting to explain rainbows and meteors.

2. Biography

Anaxagoras is believed to have enjoyed some wealth and political influence in his native town of Klazomenai. However, he supposedly surrendered this out of a fear that they would hinder his search for knowledge.

The Roman author Valerius Maximus preserves a different tradition:

Anaxagoras, coming home from a long voyage, found his property in ruin, and said:

If this had not perished, I would have—a sentence described by Valerius as being possessed of sought-after wisdom

Anaxagoras was a Greek citizen of the Persian Empire and had served in the Persian army; he may have been a member of the Persian regiments that entered mainland Greece during the Greco-Persian Wars.

Though this remains uncertain, it would certainly explain why he came to Athens in the year of Battle of Salamis, 480/79 B.C.

Anaxagoras is said to have remained in Athens for 30 years.

Pericles, the Athenian general and political leader, learned to love and admire him, and the poet Euripides derived from him an enthusiasm for science and humanity.

Anaxagoras brought philosophy and the spirit of scientific inquiry from Ionia to Athens.

His observations of the celestial bodies and the fall of meteorites led him to form new theories of the universal order, and to prediction of the impact of meteorites.

Plutarch 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 down to earth.

Plutarch

According to Pliny he was credited with predicting the fall of the meteorite in 467.

He attempted to give a scientific account of eclipses, meteors, rainbows, and the Sun, which he described as a mass of blazing metal, larger than the Peloponnese;

his theories about eclipses, the Sun and Moon may well have been based on observations of the eclipse of 463 BCE, which was visible in Greece.

He also said that the Moon had mountains and believed that it was inhabited.

The heavenly bodies, he asserted, were masses of stone torn from the Earth and ignited by rapid rotation.

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.

He thought the Earth was flat and floated supported by 'strong' air under it and disturbances in this air sometimes caused earthquakes.

These speculations made him vulnerable in Athens to a charge of asebeia (impiety).

Diogenes Laertius reports the story that he was prosecuted by Cleon for impiety, but Plutarch says that Pericles sent his former tutor, Anaxagoras, to Lampsacus for his own safety after the Athenians began to blame him for the Peloponnesian war.

The charges against Anaxagoras may have stemmed from his denial of the existence of a Solar or Lunar Deity.

According to Laertius, Pericles spoke in defence of Anaxagoras at his trial, c. 450.

Even so, Anaxagoras was forced to retire from Athens to Lampsacus (c. 434 – 433). He died there in around the year 428.

Citizens of Lampsacus erected an altar to Mind and Truth in his memory, and observed the anniversary of his death for many years.

They placed over his grave the following inscription:

Here Anaxagoras, who in his quest of truth scaled heaven itself, is laid to rest.

Anaxagoras wrote a book of philosophy, but only fragments of the first part of this have survived, through preservation in work of Simplicius of Cilicia in the 6^th century AD.

3. Philosophy

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. There was an infinite number of homogeneous parts (ὁμοιομερῆ) as well as heterogeneous ones.

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 Mind or Reason (νοῦς, Nous).

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 in all the forms of life.

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.

Decrease and growth represent a new aggregation (σὐγκρισις) and disruption (διάκρισις).

However, the original intermixture of things is never wholly overcome:

Each thing contains in itself 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. Out of this process arise the things we see in this world.

4. Mixture and Rotation

The original state of the Cosmos was an unlimited (Apeiron) mixture of all the ingredients.

The mixture of ingredients, all with all, exists eternally. Up to some point in the past, it was motionless, and it was everywhere undifferentiated, or almost so.

According to Simplicius, the source for the fragment, says was near the beginning of Anaxagoras’ book:

All things were together, unlimited both in amount and in smallness, for the small, too, was unlimited.

And because all things were together, nothing was evident on account of smallness;

for air and ether covered all things, both being unlimited, for these are the greatest among all things both in amount and in largeness.

This undifferentiated mass includes all there is of all the natural ingredients that there are, the ingredients that will eventually form the natural constructs that constitute the Cosmos as we know it.

Nothing is ever added to or subtracted from this storehouse of stuffs, although the mass of stuffs is not always homogeneous. In fact, there are different densities of ingredients even at this earliest (pre-motion) stage.

Air (dark, moist stuff) and Ether (bright fiery stuff) are the most emergent (largest) ingredients, and their dominance means that the original mixture must have been like a dense bright cloud: nothing else would be evident or manifest, even had there been an observer.

At some point Nous (the time being right) set the mixture in motion and caused it to begin to revolve (first in a small area, and then in an ever-widening area).

The rotary motion causes the ingredients in the mass to shift. This shifting produces what Anaxagoras calls separating off.

Because the mass is a plenum, any separation will be a rearrangement (thus a mixing) of ingredients. The continuous ever-expanding rotation produces more and more separation.

The Everything-in-Everything principle continues to hold, so there are all ingredients at all places at all times, but the different densities of ingredients allow for local variations, and so the rotating mass becomes qualitatively differentiated.

5. Mind/Intellect

According to Diogenes Laertius, Anaxagoras acquired the nickname Mr. Mind;

his view that the Cosmos is controlled by Nous, mind or intelligence, first attracted and then disappointed Socrates (Plato, Phaedo 97b8ff.).

Plato and Aristotle applauded Anaxagoras for using Nous as the first principle of motion, but both criticized him for failing to be consistent in that use,

arguing that once he invoked Mind to set the original mixture in motion, Anaxagoras reduced later causes to mindless mechanism.

Anaxagoras is adamant that Nous is completely different from the ingredients that constituted the original mixture (Apeiron). It is the only thing to which the Everything-in-Everything principle does not apply.

Mind is present to some things, but it is not an ingredient or share as flesh and blood are ingredients in a dog:

In everything there is a share of everything except Nous, but there are some things in which Nous, too, is present.

/B11/

In B12 (the longest extant fragment), Anaxagoras claims that if Nous were just another ingredient, it could neither know nor rule in the way that it does.

The other things have a share of everything, but Nous is unlimited and self-ruling and has been mixed with no thing, but is alone itself by itself.

For if it were not by itself, but had been mixed with anything else, then it would partake of all things, if it had been mixed with anything (for there is a share of everything in everything just as I have said before);

and the things mixed together with it would thwart it, so that it would control none of the things in the way that it in fact does, being alone by itself.

For it is the finest of all things and the purest, and indeed it maintains all discernment about everything and has the greatest strength.

(59 B12, in part)

Mind/Intellect plays a number of roles in Anaxagoras’ system:

First, it inaugurates the rotation of the mass of ingredients; it then controls that rotation, and the local rotations that take place within the large whirl that is the whole Cosmos:

Nous controlled the whole revolution, so that it started to revolve in the beginning:

First it began to revolve from a small region, but it is revolving yet more, and it will revolve still more…

And whatever sorts of things were going to be, and whatever sorts were and now are not, and as many as are now and whatever sorts will be, all these Nous set in order.

And Nous also ordered this revolution, in which the things being separated off now revolve, the stars and the sun and the moon and the air and the ether.

This revolution caused them to separate off.

(59 B12, in part)

Nous then is not only first cause, it also, one might say, is the preserver of order in the Cosmos, as it maintains the rotations that govern all the natural processes.

Anaxagoras does not explain how these processes work, or how Nous can affect the ingredients.

But there is a hint of his reasoning in a comment in Aristotle (Metaphysics I.3.984b15):

When someone said that Nous is present — in nature just as it is in animals — as the cause of the Cosmos and of all its order, he appeared as a sober man among the random chatterers who preceded him.

(We know that Anaxagoras clearly held these views, but Hermotimus of Klazomenai gets the credit for holding them earlier.)

Aristotle

Just as we control our bodies by our thoughts, so the Cosmos is controlled by Nous; we may be unclear about the details, but the results are obvious to us.

One fundamental point about Anaxagoras’ theory of Mind is that he nowhere in the extant material identifies Mind with a Divine Principle or God.

In fragment 1018 and in Trojan Women (886), Euripides says that Mind is God in each of us, and connects the necessity of the universe with Zeus and mind, and these claims are thought to have been influenced by Anaxagoras’ views.

Although later testimonial reports in Aetius and Iamblichus say that Anaxagoras connected Nous and God, there are many more reports of his denial of divinity to the heavenly bodies and his alleged atheism.

Nous is the most powerful thing in the Cosmos, controlling the rotation and all ensouled things. Part of that power and control lies in its powers of knowledge.

Anaxagoras asserts that Nous has all judgment and discernment about all things; moreover, this knowledge extends to everything that emerges from the mixtures and dissociations caused by the original rotation:

And Nous discerned them all:

the things that are being mixed together, the things that are being separated off, and the things that are being dissociated.

And whatever sorts of things were going to be, and whatever sorts were and now are not, and as many as are now and whatever sorts will be, all these Nous set in order.

(B12, in part)

This suggests a beginning of an answer to the objections lodged against Anaxagoras’ use of Nous as a cause:

While Nous is not the teleological and ethical cause for which Socrates was searching in the Phaedo, Nous could serve as an ultimate explanation.

Anaxagoras nowhere says that Nous arranges things in a certain way because it is best for them to be so, or even suggests something like an Aristotelian final cause.

Things are the way they are because that is the way things have unfolded since Nous first set everything in motion, and as it continued to move them

Anaxagoras links Mind and Soul:

Nous has control over all things that have soul, both the larger and the smaller.

This suggests not only that Anaxagoras took the actions of humans and animals as the model for how Nous controls the Cosmos, but also suggests how Nous differs from the other ingredients.

He claims that Nous is the purest and finest of all things.

Some scholars argue that it is only in Plato that we meet a genuine notion of the immaterial,

but Anaxagoras’ denial that Nous is mixed with or partakes of other ingredients (while still being in some of them)

and his insistence on its fineness and purity may suggest that he is thinking of Mind as a non-corporeal entity that can pervade and control a body or even the whole Cosmos without being a material part of it.

On either interpretation, if Nous were simply an ordinary ingredient on a par with the other basic ingredients, then, as Anaxagoras notes in B12, its relative smallness would allow it to be swamped and overcome by the other ingredients.

6. Anaxagorean Cosmos

Anaxagoras gave a complete account of the universe: of the heavens, the earth, and geological and meteorological phenomena.

The accounts of the action of Nous and the original rotation and its consequences appear in the fragments:

Fragments describe the force and velocity of the rotation, explain the beginning of the rotation and the subsequent breaking up and remixing of the mass of ingredients, and specify the cosmological consequences of the continued rotation.

Most of the other information comes from the testimonies, but there is enough in the remaining fragments to make it clear that everything is ultimately explained by the Great Rotation set in motion by Nous.

Further, and intriguingly, Anaxagoras claims that the cosmic rotary motion could produce other worlds like our own.

7. Cosmology

The rotation of the mixture begins in a small area, and then spreads out through the mass.

As the extent of the mixture is unlimited (or infinite, Apeiron), the rotation and expansion will continue forever, bringing more and more ingredients into the whirl.

The force and speed of the rotation is much faster at the edges, where the expanding rotation meets the as-yet-unmoved mass of ingredients:

What we perceive of the rotation (probably the motions of the heavens) is much slower than the unobserved rotation.

The force is enough to pull apart and rearrange the ingredients:

When Nous began to move [things], there was separation off from the multitude that was being moved, and whatever Nous moved, all this was dissociated;

and as things were being moved and dissociated, the revolution made them dissociate much more.

(B13)

There are 2 sorts of dissociation:

First, as the rotation enters the as-yet-unmoved mass of ingredients, that mass begins to break up and the ingredients start to shift in their concentrations.

This causes the original arrangement of ingredients to break up and begin to be rearranged.

Because the mixture is a plenum, any separation is at the same time a rearrangement of ingredients.

Then, those new rearrangements are themselves subject to further break-up and further rearrangement.

Anaxagoras reminds his readers that all of the changes are ultimately traceable to the action of Nous, or Mind, that sets the mass moving in the first instance.

Over time, the rotation throws lighter ingredients towards the edges of the whirl and pushes the heavier ones to the centre, thus putting more dark and heavy ingredients like earth in the centre and throwing air and ether (fire) away from the centre.

This gives the traditional Greek picture of our Earth (itself a mixture of all ingredients, with earth and heavy ores and minerals predominating) covered (in many places) by water, with Air and the fiery reaches of the heavens.

The Sun is a mass of fiery metal, and the Moon is an earthy lump (with no light of its own). The same rotation ultimately produces the stars and planets as well.

Sometimes the force of the rotation snatches up stones from the surface of the Earth and spins them around the Earth as they gradually rise higher through the force of the rotation.

Until these bodies are high enough, they remain unseen between the Earth and the moon and so sometimes intervene to prevent heavenly bodies from being seen by terrestrial observers.

The force and shaking of the rotation can cause slippage, and so sometimes a Star (a flaming mass of rock and iron) is thrown downwards toward the earth as a Meteor.

The fullest account of Anaxagoras’ view on Meteors can be found in Plutarch’s Life of Lysander.

According to the ancient sources, Anaxagoras also gave explanations for the light of the Milky Way, the formation of comets, the inclination of the heavens, the solstices, and the composition of the moon and stars.

8. Meteorology and Geology

The rotation begun by Nous ultimately affects phenomena on the earth and above the surface of the earth.

Anaxagoras claims that the Earth is Flat, rests on Air, and remains where it is because of its size. Despite the manner of its formation, the Earth is stationary, not spinning.

The (relative) flatness of the Earth allows water to spread over the earth, with mountains and plains rising above the level of the water.

The levels change as water is evaporated or added by rain, and as water that has been trapped in the earth by the rotation makes its way out through rivers to the sea.

Because the Air under the Earth is also moving (pushed along by the cosmic rotation), it sometimes gets caught up in the crevices of the earthy stuff. When this Air cannot make its way out, the force of the moving air causes earthquakes.

Anaxagoras seems determined to explain everything.

The extant sources report views on thunder and lightning, the source of the Nile, the first correct account of the nature of hail, and inquiry into why the sea is salty.

He also offered accounts of sense perception and made inquiries into embryology.

9. Anaxagoras’ Influence

Reportedly the first of the Pre-Socratic philosophers to settle in Athens, Anaxagoras was a significant figure, not only for later philosophical thinkers, but also for the wider civic culture of his time.

He was clearly an important influence on Pericles.

Plutarch reports:

But Anaxagoras of Klazomenai was the one who most associated with Pericles and who most bestowed on him that dignity and wisdom more weighty than demagoguery, and on the whole raised up and exalted the worthiness of his character …

These are not the only advantages that Pericles enjoyed because of his connection with Anaxagoras:

It seems that Pericles rose above superstition,

that attitude of astonishment about celestial occurrences which is produced in those who are ignorant about the causes of things and who are crazed by divinity and divine interventions because of their inexperience in these areas.

Natural philosophy substitutes for festering superstition that unshaken piety that is attended by good hopes.

Plutarch

That naturalism appears in the dramas of Euripides, who is often described as a pupil of Anaxagoras, and in the comedies of Aristophanes, who satirizes the views of Anaxagoras as well as the figure of Socrates in Clouds.

Anaxagoras’ theory of the floods of the Nile was known to Herodotus (and may be referred to in Aeschylus).

Despite stories that they did not get along, there are signs of influence of Anaxagoras on Democritus (in his accounts of perception and knowledge) and Anaxagoras’ scientific claims and discoveries affected all the thinkers of his time.

Once his views about meteors, hail, and eclipses became known, such topics were always included in scientific accounts of astronomical and meteorological phenomena.

In the testimonies, Anaxagoras’ even temperament was taken as a model of good behaviour, and he was famous as a prognosticator of everything from meteor falls to rain showers.

Anaxagoras’ views appear among Socrates’ survey of previous naturalistic theories of explanation (Phaedo).

More ominously, Meletus seems to have attributed Anaxagoras’ claims about the earthy nature of the moon and stars to Socrates at his trial (in Plato’s Apology).

Although Anaxagoras’ alleged indictment for impiety was probably as much political as a sign of his danger to public religion (attacking Anaxagoras was an indirect attack on Pericles), he was seen as important and influential enough to qualify to some as an enemy of the polis.

Philosophically, Anaxagoras’ theories were also widely known and influential.

Anaxagoras’ view that each one is and was most manifestly those things of which there are the most in it (the principle of Predominance)

is echoed in Plato’s claims that sensible things acquire their characters and names from the Forms in which they participate (Phaedo).

Plato even adopts Anaxagoras’ language of sharing or participating in, and like Anaxagoras’ Nous, Platonic Forms are themselves by themselves in being self-explanatory.

Aristotle, although impatient with the gaps in Anaxagoras’ account of Nous, expresses admiration for his recognition that Mind has a role to play in guiding the Cosmos, and he treats Anaxagoras’ explanation of eclipses as a model of scientific explanation.