Anaximenes of Miletus
Anaximenes of Miletus as imaginatively depicted, wearing a tainia, in a 16th century engraving from Girolamo Olgiati.
Bornc. 586/585 BC
Diedc. 526/525 BC (aged c. 60)
EraPre-Socratic philosophy
RegionWestern philosophy
SchoolIonian/Milesian school
Main interests
Natural philosophy
Notable ideas
Air is the arche
Matter changes through rarefaction and condensation

Anaximenes of Miletus (/ˌænækˈsɪməˌnz/; Greek: Ἀναξιμένης ὁ Μιλήσιος; c. 586/585 – c. 526/525 BC) was an Ancient Greek, Pre-Socratic philosopher from Miletus in Anatolia (modern-day Turkey) active in the 6th century BC. He was the last of the three philosophers of the Milesian School, regarded by historians as the first philosophers of the Western world. Anaximenes is best known and identified as a younger friend or student of Anaximander, who was himself taught by the first philosopher in the Greek tradition, Thales, one of the Seven Sages of Greece.

The life and views of Anaximenes remain obscure as none of his work has been preserved, and he is only known through comments about him made by later writers. Historians and philosophers consider his cosmological views to be similar to his two Milesian predecessors. Thales proposed that all matter was made of water; Anaximander proposed all matter was made of apeiron—something indefinite rather than something specific; and Anaximenes proposed that all matter was made of air. According to Anaximenes, more condensed air made for colder, denser objects and more rarefied air made for hotter, lighter objects. Anaximenes also believed that the Earth and other celestial bodies were flat and tilted, in the shape of a table (or trapezoid), and that they floated on air.


Anaximenes, the son of Eurystratos, was from Miletus, an Ionian Greek town on the western coast of Anatolia near the mouth of the Maeander River.[1][2] He is considered to be the third philosopher in the Western tradition, after Anaximander, who came after Thales, who was one of the Seven Sages of Greece.[3]

Map of Asia minor. Millawanda is Miletus
Greek settlements in Ionia

The exact dates of Anaximenes' life are lost to history. Anaximenes is considered by Aristotle's follower Theophrastus (as relayed by Simplicius) to have been the younger pupil of Anaximander,[4] and he is also considered old enough to have influenced Pythagoras.[1][5][6]

According to Diogenes Laertius in Lives and Opinions of Eminent Philosophers, a principal source for the history of ancient Greek philosophy, the chronologist Apollodorus of Athens estimated Anaximenes' lifespan by surmising that he flourished at the same time that the Persian king Cyrus the Great defeated the Lydian king Croesus at the Battle of Thymbra and subsequent Siege of Sardis in 546 BC.[7][8][9][a] Apollodorus identified one's acme (Ancient Greek: ἀκμή) or peak of achievement as taking place when one was 40 years old, which he used for when one was flourishing, placing the birth of Anaximenes at 586 BC.[11]

Other inferences suggest a similar time period: the Eclipse of Thales on May 28, 585 BC, interrupting a battle in a war between the Medes and the Lydians, is used to date when Thales flourished. Historians believe that Anaximenes was born around when Thales flourished and that he flourished when Thales died.[7][12][13]

According to classicist John Burnet, Anaximenes was considered to be a more important figure than his teacher Anaximander during his life.[5][14] Some of Anaximenes' writings are referenced during the Hellenistic period, but no record of those documents currently exist.[b] Further details of his life and philosophical views are obscure, as none of his work has been preserved, and he is only known through fragments and interpretations of him made by later writers and polemicists, such as Aristotle.[16] Anaximenes is identified by the number 13 in the standard, fifth edition of the Diels–Kranz numbering system.[17]

Air as the arche

See also: Classical element § Hellenistic philosophy

According to Aristotle, and his follower Theophrastus, each philosopher of the Milesian School was a material monist who sought to discover the arche (Ancient Greek: ἀήρή, lit.'beginning, origin'): the one, underlying basis of all things.[4][18][c] Aristotle called the first philosophers physiologoi (Ancient Greek: φυσιολόγοι), natural philosophers.[20] Anaximenes thought that air—or, literally, aer, which may also include mist or vapor[8]—was the primary substance that held the universe together.[16]

Anaximenes' views have been interpreted as reconciling those of his two predecessors, Thales and Anaximander. Air as the arche has the feature of being one thing which seems unlimited (like Anaximander, who thought the arche was apeiron (Ancient Greek: ἄπειρον, lit. 'unlimited, 'boundless'), but is a determinate substance, like Thales with water and unlike Anaximander.[19] He also viewed air as the substance most capable of change because he saw air as always being in motion.[21]

If air is breathed out through the mouth during cold and humid conditions, water vapor will condense into a visible cloud or mist

Anaximenes also believed that air was divine.[2][4][21][d] He identified air with the "breath of life", and thus the soul as well as the air in the atmosphere.[8][24][25][e] Only a single, sentence-long quote by Anaximenes survives: "Just as our soul ... being air holds us together, so pneuma and air encompass [and guard] the whole world."[27][28][29] This is the first extant source to use the word pneuma (Ancient Greek: πνεῦμα, lit.'breath').[30]

Condensation and rarefaction

Philosophers have concluded that Anaximenes seems to have based his conclusions on naturally observable phenomena in the water cycle: the processes of rarefaction and condensation.[31] Anaximenes attributed cold or wet air to condensation and hot or dry air to rarefaction,[2][15][32] as illustrated by blowing on one's hand with pursed lips and feeling cold air, or with an open mouth and feeling warm air.[33]

Anaximenes reasoned that differences in the degree of condensation and density of air produced all matter.[24] According to Anaximenes, the "loose",[26] spread-out, infinite air was condensed to wind, then formed into clouds, which condensed further to produce rain, snow, and other forms of precipitation.[24][26] The process continued until the air was condensed or felted enough to be tangible and form solids like dirt, and ultimately stones. By contrast, just as water evaporates into air, air could further rarefy into fire or light.[8]

Anaximenes of Miletus as depicted in the Nuremberg Chronicle (1493)

While Thales and Anaximander also recognized transitions in states of matter, Anaximenes was the first philosopher to associate the qualitative change in hot/dry and cold/wet pairings with the quantitative density of a single material.[34][35] However, "for him density was a quantitative notion only in the weakest sense".[36]


Astrology by the 16th-century Dutch engraver Cornelis Cort has a book labeled "Anaximenes.

Anaximenes used air to explain the nature of the Earth and the surrounding celestial bodies. In the beginning of the world, air condensed to create the flat surface of the Earth, which he said was shaped like a table (or trapezoid),[f] and was tilted.[38][39][40] According to Aristotle in On the Heavens, Anaximenes thought that the world stayed still by floating like a lid covering the air beneath it.[41][42][g]

Anaximenes said that the Sun floated on air like a broad leaf,[45] and that the Moon also floated on air.[2] He thought of stars as similar to nails that are stuck in a transparent shell.[46][8] In keeping with the prevailing view of stars 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.[47] While the Sun is similarly described as being a flame, Anaximenes thought it was not composed of rarefied air like the stars, but rather of Earth like the Moon. According to Pseudo-Plutarch, Anaximenes thought that its burning comes not from its composition, but rather from its rapid motion.[42][30][48]

According to the Christian polemicist Hippolytus in the Refutation of All Heresies, Anaximenes believed that when the Sun set, it did not pass under the Earth, but was merely obscured by higher parts of the Earth as it circled around and became more distant.[2][40] Aristotle relates that "many of the ancient cosmologists" held a similar belief.[49] Hippolytus likens the motion of the Sun and the other celestial bodies on this view to a hat, going around the Earth "just as a cap is turned round our head."[50][51]

Anaximenes believed that the sky was a dome and that that dome was the outer frontier of the Earth.[52] He also believed that day and night are caused by celestial bodies being carried North until they are no longer seen. There is evidence to suggest that Anaximenes may have been the first person to distinguish between planets and fixed stars.[8] The Anaximenes crater on the Moon is named in his honor.[53]

Weather and other natural phenomena

Anaximenes also described the causes of other natural phenomena. Earthquakes, he asserted, were the result either of lack of moisture, causing the earth to break apart, or of a superabundance of water, causing cracks in the earth.[54] In either case, the earth becomes weakened by its cracks, so that hills collapse and cause earthquakes. Lightning was similarly caused by the violent separation of clouds by the wind, creating a bright, fire-like flash. Rainbows, on the other hand, were formed when densely compressed air is touched by the rays of the sun.[51][55]


The ruins of Miletus

Pre-Socratic philosophy

The theories of Anaximenes were likely influential upon later Presocratic philosophers.

In response to the Ionian Revolt, Miletus was captured by the Persian army of Darius the Great in 494 BC, killing the men and enslaving the women and children.[26][30][56] Similarly to Anaximenes, the Pythagoreans, according to Aristotle, believed that the world breathed; that there was "boundless breath" which was "outside the heavens, and ... was inhaled by the world".[57][58] Xenophanes claimed that rainbows were clouds, which, on one interpretation, is a response to Anaximenes' idea that rainbows are caused by light being reflected off of clouds.[59] Xenophanes' theory that the arche is earth and water has also been interpreted as a response to Anaximenes.[60]

The cosmology of Anaxagoras shared many similarities with that of Anaximenes, and was likely influenced by it,[21][61][62] while the atomists Democritus and Leucippus adopted Anaximenes' view that the world was flat.[5][41][63] Diogenes of Apollonia attempted to amalgamate the theories of Anaximenes with those of Anaxagoras.[64] He took up the view of Anaximenes' that air was the arche, and that all substances were the result of the condensation and rarefaction of air.[5][65]


In the Timaeus, Plato favorably mentions Anaximenes' theory of matter and its seven states from stone to fire. Plato treats Anaximenes as a kind of philosopher of process rather than a material monist, as Aristotle portrays him. From this perspective, Anaximenes is viewed as a forerunner of Heraclitus and ultimately Plato, rather than Diogenes of Apollonia.[66][67][68] Scholars have noted that Plato may have been referencing Anaximenes in the Phaedo when he states: "And so one man makes the earth stay below the heavens by putting a vortex about it, and another regards the earth as a flat trough supported on a foundation of air."[30][69]


Aristotle is the oldest extant writer to reference Anaximenes by name.[68] Aristotle also alluded to Anaximenes' thought without specifically referencing him. For example: "Diogenes, ... as also some others, identified soul with air. Air, they thought, is made up of the finest particles and is the first principle."[70][71] Aristotle in Generation of Animals calls pneuma the "vital heat".[72][73][74]


The Stoics believed pneuma to be a mix of the elements fire and air. In a view reminiscent of Anaximenes, Chrysippus believed pneuma is what moved the body, and what held everything together.[75][76] It existed in men as nous, in animals as psyche, in plants as physis, and in inanimate objects as hexis (Ancient Greek: 'ἕξις, lit.'possession, habit'), or qualities and dispositions. "Whiteness" for example, was ultimately air.[77]


  1. ^ Cyrus the Great would a few years later defeat Babylon, ending the Babylonian captivity.[10]
  2. ^ According to Diogenes Laertius he wrote straightforwardly, in the "pure unmixed Ionian dialect."[1][15]
  3. ^ Scholars have argued that they were arguably being anachronistic by imposing the Aristotelian notion of substance on earlier philosophy.[19]
  4. ^ Thales said everything was "full of gods".[22][23]
  5. ^ While Anaximenes was a pagan philosopher, Vamvacas has noted that the Old Testament features a similar image of the breath of life in the founding of the world and creation of man in Genesis 2:7.[26]
  6. ^ The word trapezoid (Ancient Greek: τραπεζοειδῆ) comes from the Greek trapeza, meaning "table", and -oeides, meaning "shaped." In light of this ambiguity, scholars have contended that Anaximenes believed that the world was shaped like a trapezoid, rather than a flat circle.[37]
  7. ^ This view of the Earth has been analogized to that of a frisbee or disc.[43][44]



  1. ^ a b c Laërtius 1925, p. 57-58 (DK13A1)
  2. ^ a b c d e Hippolytus, Refutation of All Heresies 1.7.1 - 1.7.6 (DK13A7)
  3. ^ Hussey 2005, p. 33
  4. ^ a b c Simplicius, On Aristotle, Physics p. 151, 24 (DK 13A5)
  5. ^ a b c d Burnet 1930, p. 78-79.
  6. ^ Kerferd, G. B. “The Date of Anaximenes.” Museum Helveticum, vol. 11, no. 2, 1954, pp. 117–21. JSTOR, Accessed 28 Apr. 2023.
  7. ^ a b A.A. Mosshammer, 'Geometrical proportion and the chronological method of Apollodorus', Transactions of the American Philological Association 106 (1976) 291-306
  8. ^ a b c d e f Dye, James (2014), "Anaximenes of Miletus", Biographical Encyclopedia of Astronomers, Springer New York, pp. 74–75, doi:10.1007/978-1-4419-9917-7_49, ISBN 9781441999160
  9. ^ Lindberg 2007, p. 28.
  10. ^ Augustine, City of God, Book 18
  11. ^ Encyclopedia of Classical Philosophy, p. 44
  12. ^ Kirk, Raven & Schofield 1957, p. 143
  13. ^ Burnet 1930, p. 72.
  14. ^ see also Barnes 1982, p. 39
  15. ^ a b Guthrie 1962, p. 115
  16. ^ a b Great lives from history. The ancient world, prehistory-476 C.E. Salowey, Christina A., Magill, Frank N. (Frank Northen), 1907–1997. Pasadena, Calif.: Salem Press. 2004. ISBN 978-1587651526. OCLC 54082138.((cite book)): CS1 maint: others (link)
  17. ^ Diels, Hermann and Walther Kranz. Die Fragmente der Vorsokratiker. Zurich: Weidmann, 1985.
  18. ^ Lindberg 2007, p. 29.
  19. ^ a b Algra 1999, p. 57
  20. ^ Aristotle, Metaphysics, 986b
  21. ^ a b c Cicero, De Natura Deorum i. 26 (DK 13A10)
  22. ^ Aristotle, On the Heavens 1.5 411a7-8
  23. ^ Herbert Ernest Cushman. A beginner's history of philosophy. p. 26.
  24. ^ a b c "Anaximenes Of Miletus | Greek philosopher". Encyclopedia Britannica. Retrieved 2018-11-30.
  25. ^ Guthrie 1962, pp. 127–128
  26. ^ a b c d Vamvacas 2009.
  27. ^ Aetius, i. 3, 4 (DK13B2)
  28. ^ Burnet 1930, p. 73.
  29. ^ Vamvacas 2009, p. 47
  30. ^ a b c d Kirk, Raven & Schofield 1957, pp. 152–153
  31. ^ Guthrie 1962, p. 116
  32. ^ Vamvacas 2009; Lindberg 2007, p. 29.
  33. ^ Plutarch, The Principle of Cold, 7 947 F (DK13B1)
  34. ^ Guthrie 1962, pp. 124–126
  35. ^ Kirk, Raven & Schofield 1957, p. 146
  36. ^ Barnes 1982, p. 46
  37. ^ Peter H. Gommers (2001). What's In A Name. p. 30. ISBN 9789058671493.
  38. ^ Burnet 1930, p. 77.
  39. ^ Pseudo-Plutarch, Placita philosophorum 895d
  40. ^ a b Couprie, Dirk L. (2018), "Peculiarities of Presocratic Flat Earth Cosmology", When the Earth was Flat: Studies in Ancient Greek and Chinese Cosmology, Historical & Cultural Astronomy, Springer, pp. 19–46,, doi:10.1007/978-3-319-97052-3, ISBN 9783319970516
  41. ^ a b Aristotle, On the Heavens 294b (DK13A20)
  42. ^ a b Pseudo-Plutarch, Stromata, 3 (DK13A6)
  43. ^ Routledge Companion to Ancient Philosophy. Routledge. 4 December 2013. p. 22. ISBN 9781317975502.
  44. ^ Andrew Gregory (2003). Eureka. p. 24. ISBN 9781840463743.
  45. ^ Aetius 2.22
  46. ^ Aetius 2.14
  47. ^ Eduard Zeller. Outlines of the History of Greek Philosophy. p. 41-43.
  48. ^ Kočandrle, Radim (2019). "The Cosmology of Anaximenes". History of Philosophy Quarterly. 36 (2): 101–120. doi:10.2307/48563639. JSTOR 48563639. S2CID 246623749.
  49. ^ Aristotle Meterologica II, 1,354a28
  50. ^ Graham, Daniel W. "Anaximenes". The Internet Encyclopedia of Philosophy.
  51. ^ a b Fairbanks 1898, p. 20-21
  52. ^ Pseudo-Plutarch, placita philosophorum 888b
  53. ^ Cocks, Elijah E.; Cocks, Josiah C. (1995). Who's Who on the Moon: A Biographical Dictionary of Lunar Nomenclature. Tudor Publishers. p. 13. ISBN 978-0-936389-27-1.
  54. ^ Aristotle Meterologica 2.7 365b6-12 (DK 13A21)
  55. ^ Guthrie 1962, p. 139
  56. ^ Siege of Miletus
  57. ^ Aristotle, Physics Δ, 6. 213 b 22
  58. ^ Burnet 1930, p. 79, 108.
  59. ^ Xenophanes (January 2001). James H. Lesher (ed.). Fragments. p. 140. ISBN 9780802085085.
  60. ^ McKirahan, Richard D. (1994). "Xenophanes of Colophon". Philosophy Before Socrates: An Introduction with Texts and Commentary. Hackett Publishing Company. pp. 65–66. ISBN 978-0-87220-175-0. Retrieved 13 April 2022.
  61. ^ Burnet 1930, p. 270
  62. ^ Strabo, Geography, Book 14
  63. ^ Barnes 1982, p. 26
  64. ^ Burnet 1930, p. 145.
  65. ^ Burnet 1930, p. 353–358.
  66. ^ Graham, Daniel W. (2015-12-30). "Plato and Anaximenes". Études Platoniciennes (12). doi:10.4000/etudesplatoniciennes.706. ISSN 2275-1785.
  67. ^ Graham, D. (2003). "A testimony of Anaximenes in Plato". The Classical Quarterly. 53 (2): 327–337. doi:10.1093/cq/53.2.327.
  68. ^ a b Graham, Daniel. The Texts of Early Greek Philosophy. p. 91.
  69. ^ Phaedo, 99b
  70. ^ Aristotle, On the Soul, 405a21
  71. ^ P. J. Bicknell (1966). "TO ΑΠΕΙΡΟΝ, ΑΠΕΙΡΟΣ ΑΗΡ AND TO ΠΕΡΙΕΧΟΝ" (PDF). Acta Classica: 27–48.
  72. ^ Generation of Animals, 762a18-20
  73. ^ see Aristotle’s Theory of Material Substance: Heat and Pneuma, Form and Soul by Gad Freudenthal
  74. ^ Panpsychism in the West by David Skrbina, p. 57
  75. ^ The Philosophy of Chrysippus by Josiah Gould, p. 126
  76. ^ The Image of the Jews in Greek Literature by Bezalel BarKochva, p. 528
  77. ^ Theology of the Early Stoa


Further reading