Anaximenes

The third and last of the Milesian philosophers was Anaximenes, was the young associate of Anaximander. Anaximenes returned to the flat earth theory of Thales, but no longer thought of this body as floating on the surface of anything. It floated in the surrounding medium supported by that medium’s density. Like all Ionians, he believed that the medium in which it floated was also the stuff of which it is made. Like Anaximander, he conceived this stuff as a three-dimensional volume extending infinitely in every direction round the world, but in spite of Anaximander’s example, he did not see the logical necessity of conceiving it as indeterminate in quality. He went back to Thales and identified it with one specific natural substance, differing from Thales only in calling it, not water, but air or vapor. As the boundless, air is everywhere, but unlike the boundless, it is a specific and tangible material substance that can be identified. Also, the air’s motion is a far more specific process than Anaximander’s "separating off," for Anaximenes came upon the concepts of "rarefaction" and "condensation" as the specific forms of motion which lead to describable changes in the air. Although air is invisible, we live only so long as we can breathe, and "just as our soul, being air, holds us together, so do breathe and air encompass the whole world." But to explain how air is the origin of all things, Anaximenes introduced the important new idea that differences in "quality" are caused by differences in "quantity." The expansion and contraction of air represent quantitative changes, and these changes occurring in a single substance account for the multitude of different things. As Anaximenes says, "air that is condensed forms winds … if this process goes further, it gives water, still further earth, and the greatest condensation of all is found in stones."

Thus, from the point of view of the Ionian School, to which Anaximenes is conventionally assigned, Anaximenes is an example of decadence. From another point of view, he is an example of progress; and from this point of view he does not belong to the Ionian School, he is the link between it and the Pythagorean School. That he was not an Ionian is clear from two facts according to Collingwood: first, that he went back on the quite conclusive demonstration which Anaximander had shown that a really primitive universal substance must be indeterminate in quality and could therefore no more be identified with air than it could with water; secondly, that his main interest seems to have swung away from the oneness of the primitive substance to the manyness of the various natural substances, each with its own proper mode of behavior. Anaximenes had lost interest in the question: "What is the one thing out of which all things are made?" This, according to Aristotle, was the central question of Thales and his school. In so far as Anaximenes had lost interest in it he had ceased to be a member of that school.

That Anaximenes was a Pythagorean is clear from his insistence on the concept of condensation and refraction. His question was: "Why do different kinds of things behave differently?" That is not the question of Ionian physics; it is the question of Pythagorean physics. His answer was: "Because the thing, out of which they are made, no matter what that thing is, undergoes different arrangements in space." That is the Pythagorean answer. As put forward by Anaximenes it was only a bare rudiment of Pythagoreanism. The only difference of arrangement of which Anaximenes spoke was the difference between a denser and a looser packing of matter in space. Pythagoreanism was to go much further than this. That is why Anaximenes ought to be called not so much a member of the Ionian School as a link between that and the School of Pythagoras.

Although these Milesian philosophers appear to have proceeded with scientific concerns and temperaments, they did not form their hypotheses the way modern scientists would, nor did they devise experiments to test their theories. Their ideas have a dogmatic quality, a mood of positive assertion, rather than the tentativeness of true hypotheses. But it must be remembered that the critical questions concerning the nature and limits of human knowledge had not yet been raised. Nor did  the Milesians refer in any way to the problem of the relation between spirit and body. Their reduction of all reality to a material origin certainly raises this question, but it was recognized as a problem only later in the history of thought. Whatever may be the usefulness of their specific ideas about water, the boundless, and air as the primary substance of things, the real significance of the Milesians is that they, for the first time, raised the question about the ultimate nature of things and made the first direct inquiry into what nature really consists of.

 

Fragment

As our souls, being air, hold us together, so breath and air embrace the entire universe.