Anaximenes

Anaximenes of Miletus (Greek: Ἀναξιμένης; Miletus, ca.. 590 BC – between 528 and 525 BC) was a Greek philosopher, disciple of Thales and Anaximander.

He agreed with Anaximander that the beginning of all things (and also the substratum that remains invariable before all changes and the end, or telos to which everything returns) is infinite; although, unlike the ápeiron of his mentor, he speaks of a specific element: air. This substance, he claimed, is transformed into other things through rarefaction and condensation. The rarefaction generates fire, while condensation, wind, clouds, water, earth and stones; from these substances, the rest of the things are created.

The change of state of the air could be explained by the flow between two poles, the cold and the hot; but Plutarch says that Anaximenes thought otherwise, and believed that hot and cold were consequences and not causes of rarefaction and condensation respectively.

Biographical information

Anaximenes was born in Miletus, around 590 B.C. C. his father was Eurystratus.

Theophrastus describes Anaximenes as a disciple and companion of Anaximander, apparently being some 22 years younger than him.

As mentioned by Pliny the Elder in his Natural History (book II, chapter LXXVI), Anaximenes was the first to analyze the geometric computation of shadows to measure the parts and divisions of the day, and designed for this a sundial, which he calls sciothericon. Literally: «Umbrarum hanc rationem et quam vocant gnomonicen invenit Anaximenes Milesius, Anaximandri, de quo diximius, discipulus, primusque horologium, quod appellant, Lacedaemone ostendit».

Diogenes Laertius states that, according to Apollodorus, Anaximenes dies in the 63rd Olympiad (528-525 BC).

Works

He is credited with the composition of a book, Periphyseos (On Nature), a work that today has been lost but of which there is evidence thanks to Diogenes Laertius, who said of Anaximenes that he "wrote in the Ionian dialect, in a simple and concise style".

Thought

Physics

He opposes Anaximander and Thales of Miletus regarding the determination of the first principle or arché, which Anaximenes considers to be air. He probably made this choice based on experience, and the observation of living beings and the importance of the phenomenon of respiration would influence. However, air is not understood in its most literal sense, since the soul would also be of this element. Air dominates and holds the cosmos together, in the same way that the soul does with the body. It also offers a mechanism for explaining the generation of things from another element other than them: condensation and rarefaction. By condensation of the air, says Anaximenes, clouds are formed; if the clouds condense, water is formed; the condensation of water gives rise to the constitution of the earth, and the condensation of the earth gives rise to the constitution of stones and minerals. The reverse process is represented by rarefaction: stone, earth, water, clouds, air and, finally, the rarefaction of air would produce fire.

Cosmology

Anaximenes believed that the Earth was flat "like a sheet", and that it was formed by the condensation of air; the celestial bodies, also flat, were born from the Earth, due to a rarefaction of its pneuma or exhalation. These stars are made of fire ("rarified air") and they ride on the air, revolving around the Earth "as a felt hat revolves on our head." In addition, there are other bodies, solid and invisible, that would serve to explain meteorites and eclipses.

Anaximenes reconceives air as a specific element: air (pneuma). Air can be said, as has been said lines above water in the case of Tales, which is an essential element for life. The diversity of beings is due to two air processes: rarefaction and condensation. The air itself is the most expanded, a stone is very condensed air.

He observed that the sky seemed to revolve around the pole star.

Meteorology

In meteorological matters, he considered that earthquakes occur in periods of drought or when there is a lot of rain, since when the earth is dry it cracks and, with excess humidity, it melts. Lightning, thunder and lightning are formed by the wind that cuts through the clouds; the rain, when the clouds condense; hail, when the rain solidifies, and snow, when a portion of wind is added to it.

A much-discussed passage from Anaximenes says that "just as our soul, which is air, holds us together, in the same way the pneuma or air envelops the cosmos." It could indicate a certain correlation between the human being and the world, since both have an exhalation (pneuma) and are covered by the protective air. This idea would be the basis of the later popular homology between man and the world, widely used by early medicine.

Eponymy

• The moon crater Anaximenes bears this name in his memory.
• The asteroid (6051) Anaximenes also commemorates its name.