Anaxímenes

Anaximenes (6th century bc)

The Greek philosopher Anaximenes of Miletus followed Anaximander in his philosophical and scientific interests. Only a few words survive from his book, but there is enough other information to give us a picture of his most important theories. Like the other early Presocratic philosophers he was interested in the origin, structure and composition of the universe, as well as the principles on which it operates. Anaximenes held that the primary substance – both the source of everything else and the material out of which it is made – is air. When rarefied and condensed it becomes other materials, such as fire, water and earth. The primordial air is infinite in extent and without beginning or end. It is in motion and divine. Air generated the universe through its motion, and continues to govern it. The human soul is composed of air and it is likely that Anaximenes believed the entire kosmos (world) to be alive, with air functioning as its soul. Like other Presocratics, he proposed theories of the nature of the heavenly bodies and their motions, and of meteorological and other natural phenomena.

 

 

1 Air, the cosmic principle

Practically nothing is known of Anaximenes’ life. He is called the associate and the pupil of Anaximander, on which inadequate basis the ancient testimony makes him a generation younger than his teacher. He wrote a book in ’plain and simple Ionian dialect’, but like the works of the other Presocratics it has not survived, although it must be the source of the few words the sources assign to Anaximenes.

From Aristotle onwards, Thales, Anaximander and Anaximenes have been accepted as working within a single tradition: they tackled a single set of problems and used the same methods to solve them (see Thales; Anaximander ). These three Milesian philosophers initiated the Greek philosophical tradition by investigating the origin, structure and workings of the kosmos by rational means, abandoning traditional religious and mythological accounts in favour of observation and reason. It is commonly accepted that Anaximander designed important elements of his system to avoid objections he found to Thales’ views, and that Anaximenes returned to a theory closer to Thales’ but one that both avoided Anaximander’s objections and did not suffer from faults that can be found in Anaximander’s theory. On this standard view, Milesian philosophy made progress from philosopher to philosopher, and the progress was due to the use of rational criticism. While this line of interpretation is plausible for certain central elements in the thought of these three thinkers, most obviously for their views on the nature of the basic substance, it does not give an adequate picture of other facets of their wide-ranging theories. Also, it is an interpretative construct, not one based on original texts. The sources tell to some extent what the three men’s theories were, but not why they adopted them.

Where Anaximander postulated a substance of indeterminate nature, unlike anything found in the world around us, as the ultimate source of the diversity of materials found in the kosmos, Anaximenes returned to Thales’ idea of basing the kosmos on a single familiar substance. However, where Thales selected water, Anaximenes chose air. According to the standard interpretation, Anaximander rejected water because there are materials in the world, such as fire, that lack the properties of water (indeed, they have opposite properties), and so could not have arisen from or be made of water. Thus, the basic material must lack all perceptible properties. Anaximenes objected to Anaximander’s idea of founding the world on something imperceptible, indefinite and unfamiliar, and returned to a form of material monism, but one not open to Anaximander’s objection. Anaximenes held that air in its most ’even’ state (as on a clear, dry, windless day when the air seems neither hot nor cold) is imperceptible, but when it becomes more rare or more dense it turns into other kinds of materials. ’When thinned out it becomes fire, and when thickened it becomes wind, then cloud, and when thickened still more, water, then earth, then stones, and the rest come from these’ (Theophrastus, quoted by Simplicius, On Aristotle’s Physics 24.29–31, A5). The mechanisms of rarefaction and condensation engender a more sophisticated monism, according to which fire, for example, is not really different from air, but is air in a certain condition, just as ice is not really different from water, but is water in a certain state. ’And the rest come from these’ suggests (although this issue is disputed) that air occurs in certain basic forms (the ones listed above), and that other substances, such as wood or wheat, arise through some combination of them. If Anaximenes held this ’proto-chemical’ view of the composition of entities, the absence of further discussion in the sources makes it unlikely that he developed the idea through analysis of particular kinds of materials or illustrative examples of other sorts.

Anaximenes was the first reductionist. From the familiar phenomenon that when we exhale through pursed lips our breath feels cold, but when we exhale with the mouth wide open it feels warm, he concluded generally that compression is the cause of cooling and rarefaction the cause of heating, so that hot and cold depend on rare and dense (Plutarch, The Principle of Cold 947F, fr.1). The observation on which this conclusion is based is hardly a scientific experiment (although it has sometimes been called the first one), but there are many elements of scientific reasoning in the way Anaximenes begins from a repeatable result and generalizes it to an explanatory principle related to a larger theory, and also in the way he accounts for one range of phenomena in terms of another which he considers more basic. The fact that his conclusion is exactly wrong is less important than these other considerations.

Density and rarity are quantitative concepts – more or less of something in a given volume – while hot and cold are qualities. Anaximenes is thus credited with being the first to subscribe to the scientific objective (also pursued shortly afterwards by the Pythagoreans) of reducing qualities to quantities (see Pythagoreanism §2 ).This is probably a misinterpretation however. For although we define density in quantitative terms, Anaximenes need not have seen it this way. There is no reason to suppose he thought there were fixed proportions governing the changes of air, so that, for example, so much fire contains the same amount of air as so much water. He held that ice is denser than water (Aëtius, III 4.1, fr. 3), but is there more water in a cup full of ice than in a cup full of water? (Indeed, water at 4° Celsius is denser than ice, but Anaximenes was unaware of this fact.) The evidence suggests that he did not take a quantitative view of these matters, but considered air, clouds, rain, etc. as more or less dense, as if rarity and density were qualities apparent to the senses and not dependent on measurement.

Like Anaximander’s originative substance, Anaximenes’ air is described as eternally in motion and also as apeiron (’boundless’ or ’unlimited’;the word later meant ’infinite’, but in Anaximenes’ time did not yet have any precise mathematical sense), meaning that it has no limits in space or time. Not that all air is in motion all the time, since air in motion is wind, and wind is denser than air in its most ’even’ state. Thus, air is mobile, and at any given time, much of it is in motion. Moving through its own nature, it is alive, and being everlasting, it is divine. (These were also Anaximander’s reasons for regarding his basic substance as divine.)

2 The kosmos

Like other Presocratic philosophers, Anaximenes proposed a cosmogony and a cosmology that fitted his basic principles. Little information on these topics survives and some of it seems to be inconsistent. Our kosmos originated out of the self-moving air which became so dense in one region that it was ’felted’ (the word may be Anaximenes’ own), or compressed, to form earth. The earth is a flat ’table-like’ disc and so rides on the air beneath it like a leaf. There are different accounts of the heavenly bodies. According to the most plausible one, as the earth grew more dense there arose from it moisture that became rarefied and turned into fire; the fire went aloft and became the heavenly bodies. The stars do not give heat because of their great distance from the earth. Like the earth, these fiery bodies stay aloft because of their flatness. There are also earthen bodies in the heavens, which may be posited to account for eclipses. The heavenly bodies do not move underneath the earth, but around it, as when a felt cap (shaped like a yarmulke) is turned about its centre while on someone’s head. The geometry of this model is difficult to work out, but the simple and homespun analogy is characteristic of Anaximenes.

Also typical of the Presocratics is Anaximenes’ interest in meteorological phenomena. Wind, clouds, rain, etc. are condensed air. When rain freezes as it falls it becomes hail, and it becomes snow when ’something of the nature of breath’ is combined with the moisture. Anaximenes explains the rainbow, traditionally the goddess Iris, as the effect of the sun’s rays striking condensed air, and offers an account of why it has different colours. Lightning and earthquakes (the work of Zeus and Poseidon) likewise receive naturalistic explanations.

To our knowledge, Anaximenes did not discuss the origin and conditions of animal life, although this may be due to the meagre evidence we possess about his ideas. Certainly these issues were prominent with Anaximander. Anaximenes did declare that the gods are made of air, thus decisively subordinating the Olympian religion to physics. A purported quotation bears on the nature of the soul, a topic which as far as we know Anaximander did not discuss: ’As our soul, being air, holds us together and controls us, also breath and air surrounds the whole kosmos’ (fr. 2 ). This fascinating statement (some of whose language is almost certainly a rewording of the original) starts from the traditional, non-philosophical idea that the soul, or principle of life, is the breath. The soul maintains us in existence (’holds us together’) as living beings and governs our activities (’controls’), although how it governs and what activities it controls are unclear. (So, for example, we cannot tell whether the soul has cognitive or moral aspects, or whether creatures other than humans possess souls.) The point of the analogy must be that ’breath and air’ has (note the singular verb, as in the Greek of the fragment; ’breath and air’ is a single idea, perhaps equivalent to ’breath in the form of air’) similar functions in the kosmos. As it stands, the fragment is not an argument. It is an analogy, which despite its lack of probative force may reveal one of the insights that led Anaximenes to choose air as his basic substance or one that confirmed his choice. The fragment contains the first explicit use of the microcosm-macrocosm analogy in Greek thought. It suggests (although it is not certain that Anaximenes held this view) that air is the soul of the kosmos, and therefore that the entire universe is alive. This idea resembles the view attributed to Thales that all things possess soul through their connection with the divine originative substance water. Anaximenes, then, may have found air a more plausible basic substance than water because of the animating functions it possesses according to the traditional conception of the ’breath-soul’.

The last of the great Milesian thinkers, Anaximenes shared with his predecessors an interest in the natural world and the goal of explaining its principal features acceptably to human reason. His cosmology influenced many of the later Presocratics. More conservative than Anaximander in some ways, he devised a theory of the kosmos that was intellectually justifiable by the standards of his time and also closer to common experience.