Anaximenes of Miletus



Life and Work

Anaximenes (fl. c.545 BC) was a discipline of Anaximander. He is the third and the last of the Milesian philosophers. Only a few sources survive for his life and activities. He wrote a book in prose probably within the same framework of natural philosophy as that of Anaximander. Anaximenes speculated on cosmology, cosmogony and meteorology.

The Air

For Anaximenes, in contrast to Anaximander, the source of all things is not an indefinite and unlimited apeiron but the air (aer): a definite material substance. The air by the process of ‘rarefaction’ becomes fire and by the process of ‘condensation’ becomes water and earth. Hot and cold do not have an ontological or material status but they are due to rarefaction and condensation. For Anaximenes the earth is flat and rides on a cushion of air. A heavenly firmament revolves like a felt cap around it. The heavenly bodies were made by rarefaction into fire, they are also flat and rest on air.

The Soul

For Anaximenes, the air is divine and causes life. It is also the source of life which encloses the cosmos as well as the first principle that is responsible for the maintenance of all living organisms. The air is the divine psychic principle between microcosm and macrocosm. As the soul (air) of an individual organism maintains the single individual organism, so the soul of the cosmos (universal breath) surrounds and maintains the whole universe. Hence Anaximenes’ cosmos is conceived as a huge animate being with divine origins.

Fragments and Testimonies

1 (A5 from Theophrastus) Anaximenes, Anaximander's colleague, said, as he did, that there was one underlying nature, but not, as he did, that it was limitless but limited, naming it as air; and by thinning and thickening it makes individual objects different.

2(2) As our soul, which is air, maintains us, so breath and air surround the whole world.

3(2a) The sun is broad and flat, like a leaf.

Translation M. R. Wright -  note: numbers in parentheses refer to the standard Diels/Kranz order



Copyright 1997-2006

Giannis Stamatellos





  Writings and Sources

  Mythological Origins

  Pherecydes of Syros


  Thales of Miletus
  Anaximander of Miletus
  Anaximenes of Miletus

  Heraclitus of Ephesus
  Xenophanes of Colophon

  Pythagoras of Samos
  Philolaus of Croton
  Archytas of Tarantum
  Alcmaeon of Croton


  Parmenides of Elea
  Zeno of Elea
  Melissus of Samos

Empedocles of Acragas
  Anaxagoras of Klazomenes
  Democritus of Abdera