Anaximenes of Miletus

Anaximenes (b. 585 BC - d. 528 BC, ~57 years old, lived during the Archaic period (c. 750 – c. 500 BC)) was a pre-Socratic Greek philosopher who lived in Miletus, Ionia in Asia Minor (modern west coast turkey). As one of the three Milesian philosophers, he is identified as a younger friend or student of Anaximander. 

• Material Monism - all of the world's objects (or universe) are composed of a single element (the source of everything), which for Anaximenes was air, the first principle, the primary substance.
• 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
• First recorded thinker who provided a theory of change (by the processes of rarefaction and condensation), and supported it with logic and observation
• By providing cosmological accounts with a theory of change, he separated them from the realm of mere speculation and made them, at least in conception, scientific theories capable of testing

Anaximander of Miletus

Influenced: All pre-socratic philosophy, in particular, Anaximenes, Pythagoras, Democritus and Greek astronomy

Influenced by Thales of Miletus

Anaximander (c. 610 – c. 546 BC, ~64 years old, lived during the Archaic period (c. 750 – c. 500 BC)) was a pre-Socratic Greek philosopher who lived in Miletus, Ionia in Asia Minor (modern west coast turkey). He belonged to the Milesian school and learned the teachings of his master Thales.

• Father of Cosmology
• Made three important astronomical speculations: 
  • (1) that the celestial bodies make full circles and pass also beneath the earth
  • (2) that the earth floats free and unsupported in space
  • (3) that the celestial bodies lie behind one another and thought them as hollow concentic wheels
• First to write down his philosophy, earliest written in prose at least in the Western world
• Some consider him evolution's most ancient proponent
• First to create the map of the world, his innovation was to represent the entire inhabited land known to the ancient Greeks
• Introduced the gnomon to Greece from the Babylonians.
• First to employ, in a philosophical context, the term archế, the first principle, from which everything we perceive is derived. So he asked the question what is the cause of all things?
• For Anaximander this was the Apeiron (“that which has no boundaries”), an endless, unlimited primordial mass, eternal and infinite, subject to neither old age nor decay, from which all things are born and to which all things will return
• First to conceive a mechanical model of the world and the cosmos
• First to realize the obliquity (or the Earth's axial tilt)
• First known example of using an argument that is based on the principle of sufficient reason

Thales of Miletus

Influenced by Babylonian astronomy & Ancient Egyptian mathematics and religion

Influenced: Pythagoras, Anaximander (student of Thales), Anaximenes

Thales of Miletus (c. 624 BC – c. 546 BC, ~78 years old, lived during the Archaic period (c. 750 – c. 500 BC)) was a pre-Socratic Greek philosopher from Miletus, Ionia in Asia Minor (modern west coast turkey)

• Known as the Father of Western (and Greek) Philosophy as he gave a naturalistic explanation of the cosmos and supported it with reasons.
• One of the Seven Sages of Greece
• Attempted to explain natural phenomena rationally without reference to mythology, he was an original thinker
• None of his writings have survived
• He was the first to ask the question: What is the basic nature of reality?
• Material Monism - all of the world's objects (or universe) are composed of a single element (the source of everything), which for Thales was water, the first principle, the primary substance
• Made important contributions to:
  • Mathematics, particularly Geometry (as he introduced it to Greece from Egypt): Thales' theorem, Intercept theorem
  • Astronomy: prediction of a solar eclipse, determined the dates of the solstices, the diameters of the sun and moon, described the seasons, and discovered Ursa Minor.
  • Earth: the cause of earthquakes, and the Earth floats on water, possibly worked out the Earth is spherical. 
• He is credited with the first use of deductive reasoning applied to geometry, by deriving four corollaries to Thales' Theorem