Anaximenes of Miletus
Encyclopedia
Miletus
Miletus was an ancient Greek city on the western coast of Anatolia , near the mouth of the Maeander River in ancient Caria...
(b. 585 BCE, d. 528 BCE) was an Archaic Greek Pre-Socratic philosopher active in the latter half of the 6th century BC. One of the three Milesian
Milesian school
The Milesian school was a school of thought founded in the 6th century BC. The ideas associated with it are exemplified by three philosophers from the Ionian town of Miletus, on the Aegean coast of Anatolia: Thales, Anaximander, and Anaximenes...
philosophers, he is identified as a younger friend or student of Anaximander
Anaximander
Anaximander was a pre-Socratic Greek philosopher who lived in Miletus, a city of Ionia; Milet in modern Turkey. He belonged to the Milesian school and learned the teachings of his master Thales...
. Anaximenes, like others in his school of thought, practiced material monism
Material monism
Material monism is a Presocratic belief which provides an explanation of the physical world by saying that all of the world's objects are composed of a single element...
. This tendency to identify one specific underlying reality made up of a material thing constitutes the bulk of the contributions for which Anaximenes is most famed.
Anaximenes and the Arche
While his predecessors ThalesThales
Thales of Miletus was a pre-Socratic Greek philosopher from Miletus in Asia Minor, and one of the Seven Sages of Greece. Many, most notably Aristotle, regard him as the first philosopher in the Greek tradition...
and Anaximander proposed that the arche
Arche
Arche is a Greek word with primary senses 'beginning', 'origin' or 'first cause' and 'power', 'sovereignty', 'domination' as extended meanings. This list is extended to 'ultimate underlying substance' and 'ultimate undemonstrable principle'...
, the underlying material of the world, were water and the ambiguous substance apeiron
Apeiron (cosmology)
Apeiron is a Greek word meaning unlimited, infinite or indefinite from ἀ- a-, "without" and πεῖραρ peirar, "end, limit", the Ionic Greek form of πέρας peras, "end, limit, boundary".-Apeiron as an origin:...
, respectively, Anaximenes asserted that air was this primary substance of which all other things are made. While the choice of air may seem arbitrary, he based his conclusion on naturally observable phenomena in the process of rarefaction
Rarefaction
Rarefaction is the reduction of a medium's density, or the opposite of compression.A natural example of this is as a phase in a sound wave or phonon. Half of a sound wave is made up of the compression of the medium, and the other half is the decompression or rarefaction of the medium.Another...
and condensation
Condensation
Condensation is the change of the physical state of matter from gaseous phase into liquid phase, and is the reverse of vaporization. When the transition happens from the gaseous phase into the solid phase directly, the change is called deposition....
. When air condenses it becomes visible, as mist and then rain and other forms of precipitation, and as the condensed air cools Anixemenes supposed that it went on to form earth and ultimately stones. In contrast, water evaporates into air which ignites and produces flame when further rarefied. While other philosophers also recognized such transitions in states of matter, Anaximenes was the first to associate the quality pairs hot/dry and cold/wet with the density of a single material and add a quantitative dimension to the Milesian monistic system.
The Origin of the Cosmos
Having concluded that everything in the world is composed of air, Anaximenes then used his theory to devise a scheme explaining the origins and nature of the earth as well as of the surrounding celestial bodies. Air felted to create the flat disk of the earth, which he said was table-like and behaved like a leaf floating on air. In keeping with the prevailing view of celestial bodies as balls of fire in the sky, Anaximenes proposed that the earth let out an exhalation of air that rarefied, ignited and became the stars. While the sun is similarly described as being aflame, it is not composed of rarefied air like the stars but rather of earth like the moon; its burning comes not from its composition but rather from its rapid motion. The moon and sun are likewise considered to be flat and floating on streams of air, and when the sun sets it does not pass under the earth but is merely obscured by higher parts of the earth as it circles around and becomes more distant; the motion of the sun and the other celestial bodies around the earth is likened by Anaximenes to the way that a cap may be turned around the head.Other Phenomena
Anaximenes used his observations and reasoning to provide causes for other natural phenomena on the earth as well. Earthquakes he asserted were the result either of lack of moisture, which causes the earth to break apart because of how parched it is, or of overabundance thereof, which also causes cracks in the earth because of the excess of water. In either case the earth becomes weakened by its cracks and hills collapse, causing earthquakes. LightningLightning
Lightning is an atmospheric electrostatic discharge accompanied by thunder, which typically occurs during thunderstorms, and sometimes during volcanic eruptions or dust storms...
is also caused by a violent separation, this time of clouds by winds to create a bright, fire-like flash. Rainbows are formed when densely compressed air is touched by the rays of the sun. These examples further show how Anaximenes like the other Milesians looked for the broader picture in nature, seeking unifying causes for diversely occurring events rather than treating each one on a case-by-case basis or attributing them to gods or a personified nature.
See also
- The crater AnaximenesAnaximenes (crater)Anaximenes is a low-rimmed lunar crater that is located near the north-northwest limb of the Moon. It lies to the west of the crater Philolaus, and northeast of Carpenter. To the northwest is Poncelet, close to the visible edge of the Moon....
on the MoonMoonThe Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
is named in his honour. - PhilosophyPhilosophyPhilosophy is the study of general and fundamental problems, such as those connected with existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational...
- Milesian schoolMilesian schoolThe Milesian school was a school of thought founded in the 6th century BC. The ideas associated with it are exemplified by three philosophers from the Ionian town of Miletus, on the Aegean coast of Anatolia: Thales, Anaximander, and Anaximenes...
- Material monismMaterial monismMaterial monism is a Presocratic belief which provides an explanation of the physical world by saying that all of the world's objects are composed of a single element...
- ArcheArcheArche is a Greek word with primary senses 'beginning', 'origin' or 'first cause' and 'power', 'sovereignty', 'domination' as extended meanings. This list is extended to 'ultimate underlying substance' and 'ultimate undemonstrable principle'...