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History of Science Ancient Egypt

History of Science Online

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LibraryThing: Science in Ancient Mesopotamia Week 3: Ancient Egyptian and Aegean science

Anaximenes of Miletos (fl. 550 B.C.)

| Presocratics Index | Intro | Thales | Anaximandros | Anaximenes | Herakleitos | Parmenides | Zenon | Melissos |
| Atomists: Leukippos and Demokritos | Anaxagoras | Empedokles | Significance of the Presocratics |

Like those who preceded him in Miletos, Thales and Anaximandros, Anaximenes affirmed a monistic conception of the divinity -- that the first principle is one. But Anaximenes rejected water and apeiron as the ultimate principle.

Instead, Anaximenes argued that air is what everything is made of. While it may appear that the proposal of air represented a backward step after the highly abstract apeiron, air could be supported by empirical analogies from sense experience involving condensation and rarefaction. What features of air might have led him to conclude that it is the primary substance on which all else depends?

After all, our lives depend upon our next breath of air; breathing air is essential to all living things. Our dependence upon air has an unprecedented immediacy and urgency.

In addition, air can take on opposite qualities; in a way, it lies midway between all characteristics. Blow quickly on your hand with pursed lips, and air will feel cool. Exhale gently on your hand with an open mouth, and air will feel warm. Upon heating, water can turn into air. Air is powerful: when it thickens, it can blow down buildings and uproot trees. Air may thicken or condense into wind, clouds, water, earth and stones. Or it may rarify and expand into fire.

Plutarch. Prim. Frig. vii. 3, p. 947.
"According to Anaximenes, the early philosopher, we should not neglect either cold or heat in being but should regard them as common experiences of matter which are incident to its changes. He says that the compressed and the condensed state of matter is cold, while the rarefied and relaxed (a word he himself uses) state of it is heat. Whence he says it is not strange that men breathe hot and cold out of the mouth; for the breath is cooled as it is compressed and condensed by the lips, but when the mouth is relaxed, it comes out warm by reason of its rarefaction." (Hanover Historical Texts Project)

Thus, as a foundation for his theory, Anaximenes could point to observable processes occurring around us in the present day, not just analogies (like the growth of a seed).

Diogenes of Apollonia, a disciple of Anaximenes, wrote: "Neither could a plant grow out of the earth, nor any animal nor any thing else come into being unless things were composed in such a way as to be the same. But all these things arise from the same thing; they are differentiated and take different forms at different times, and return again to the same thing." (Burnet, Early Greek Philosophy, pp. 353.)

All three Milesian monists (Thales, Anaximandros, and Anaximenes), identified a single immortal divinity as the first principle that persists through change, and they conceived of it as a single universal substance.

Shortly after Anaximenes, Miletos fell in 494 B.C.

First principle
Thales of Miletos
Anaximandros of Miletos
Anaximenes of Miletos


"Once you can accept the Universe as matter expanding into nothing that is something, wearing stripes with plaid comes easy." - Albert Einstein

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HSCI 3013. History of Science to 17th centuryCreative Commons license
Kerry Magruder, Instructor, 2004
Brent Purkaple, TA

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Many thanks to the pedagogical model developed in Mythology and Folklore and other online courses by Laura Gibbs, which have been an inspiration for this course.

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This course is currently undergoing major reconstruction to bring it into alignment with the new version of the course at Janux