ANAXIMENES (c. 6th century B.C.)

Anaximenes, also from Miletus, was a younger contemporary of Anaximander, and is said to have been Anaximander's student. He is supposed to have written in a "simple and economical Ionian style" -- perhaps as a contrast to Anaximander's more poetical style.

(A) AER

(1) "Anaximenes... like Anaximander, declares that the underlying nature is one and boundless, but not indeterminate as Anaximander held, but definite, saying that it is air. It differs in rarity and density according to the substances <it becomes>. Becoming finer it comes to be fire; being condensed it comes to be wind, the cloud, and when still further condensed it becomes water, then earth, then stones, and the rest come out of those. He too makes motion eternal and says that change also comes to be through it." (R, 12)

-- Theophrastus, quoted by Simplicius, Commentary on Aristotle's Physics (24.26-25.1)

(2) "Just as our soul, being air, holds us together and controls us, so do breath and air surround the whole cosmos." (R, 12)

-- Aetius (1.3.4)

(3) "Anaximenes, son of Eurystratus, was also a Milesian. He said that the first principle is infinite air, from which what is coming into being and what has come into being and what will exist and gods and divinities come into being, while everything else comes into being from its offspring. The form of the air is this: when it is most uniform it is invisible, but it is made apparent by the hot and the cold and the moist and the moving. It is always in motion; for the things that change would not change if it were not in motion. For as it is condensed and rarefied it appears different; when it dissolves into a more rarefied condition it becomes fire; and winds, again, are condensed air, and cloud is produced from air by compression. Again, when it is more condensed it is water, when still further condensed it is earth, and when it is as dense as possible it is stones. Thus the most important factors in coming into being are opposites -- hot and cold." (R, 13)

-- EGP, p. 77

(4) "Anaximenes determined that air is a god and that it comes to be and is without measure, infinite and always in motion." (R, 13)

-- Cicero, On the Nature of the Gods (1.10.26)

(5) "Or as Anaximenes of old believed, let us leave neither the cold nor the hot in the category of substance, but <hold them to be> common attributes of matter which come as the results of its changes. For he declares that matter which is contracted and condensed is cold, whereas what is fine and "loose" (calling it this way with this very word) is hot. As a result he claimed that it is not said unreasonably that a person releases both hot and cold from his mouth. For the breath becomes cold when compressed and condensed by the lips, and when the mouth is relaxed, the escaping breath becomes warm through the rareness." (R, 13)

-- Plutarch, The Principle of Cold (7 947F)

(B) COSMOLOGY

(1) "Anaximenes... [says] that its [earth's] flatness is the cause of its staying at rest. For it does not cut the air below, but covers it like a lid, as bodies with flatness apparently do, since these are difficult for winds to move because of their resistance. They say that the earth does this same thing with respect to the air beneath. And the air, lacking sufficient room to move aside, stays at rest in a mass because of the air beneath."

-- Aristotle, On the Heavens (2.13 294b13)

(2) "Likewise the sun and moon and all other heavenly bodies, which are fiery, are carried upon the air on account of their flatness."

-- Hippolytus, Refutation (1.7.4)

(3) "He says that the stars do not move under the earth, as others have supposed, but round it, just as if a felt cap is being turned round our head; and that the sun is hidden not by passing under the earth, but through being covered by the higher parts of the earth and through its increased distance from us."

-- Hippolytus, Refutation (1.7.6)

(4) "Anaximenes says that the sun is flat like a leaf."

-- Aetius (2.22.1)

Summary

Anaximenes appears to reject Anaximander's indefinite stuff, possibly as being too vague, and as leaving wholly unclear how it creates the opposites hot and cold, and how these are created. Instead he posits aer (dense mist), which is sufficiently amorphous to produce everything else. There are two processes, condensation and rarefaction, out of which everything else is produced. Aer is condensed to form wind, then cloud, then water, then earth, then stone. Aer is also rarefied to form fire. This is supposed to replace a (more mysterious, less parsimonious) qualitative change, i.e. from one kind of thing to another, different kind of thing, with a (less mysterious, more parsimonious) quantitative change, i.e. from more or less of a thing to more or less of the same thing.