Anaximenes (585 BC - 525 BC)

Lifespan: 585 BC - 525 BC
Primary Base of Operations: Greek city of Miletos, on the coast of Asia Minor (modern day Turkey)
Schools of Thought: Milesian School, Ionians, Naturalism
Other Occupations: Cosmologist
Teacher: Anaximander

- held that the air, with its variety of contents, its universal presence, its vague associations in popular fancy with the phenomena of life and growth, is the source of all that exists. Everything is air at different degrees of density, and under the influence of heat, which expands, and of cold, which contracts its volume, it gives rise to the several phases of existence. (It was actually "aer" which he believed to be the common charecteristic between all things. "Aer" is the Greek word for a mist rather than just pure air.)
- uses his principles to account for various natural phenomena. Lightning and thunder result from wind breaking out of clouds; rainbows are the result of the rays of the sun falling on clouds; earthquakes are caused by the cracking of the earth when it dries out after being moistened by rains. He gives an essentially correct account of hail as frozen rainwater.

Anaximander (610 BC - 546 BC)

Lifespan: 610 BC - 546 BC

Primary Base of Operations: Greek city of Miletos, on the coast of Asia Minor (modern day Turkey)
Schools of Thought: Milesian School, Ionians, Naturalism
Other Occupations: Mathematician, Astronomer, Cartographer
Teacher: Thales

- understood the beginning or first principle to be an endless, unlimited primordial mass (apeiron), subject to neither old age nor decay, that perpetually yielded fresh materials from which everything we perceive is derived.

- postulated the apeiron as a substance that, although not directly perceptible to us, could explain the opposites he saw around him.
- according to him, the Universe originates in the separation of opposites in the primordial matter. It embraces the opposites of hot and cold, wet and dry, and directs the movement of things; an entire host of shapes and differences then grow that are found in "all the worlds" (for he believed there were many).
- taking into account the existence of fossils, he claimed that animals sprang out of the sea long ago. The first animals were born trapped in a spiny bark, but as they got older, the bark would dry up and break. As the early humidity evaporated, dry land emerged and, in time, humankind had to adapt.

Thales (624 BC - 546 BC)

Lifespan: 624 BC - 546 BC
Primary Base of Operations: Greek city of Miletos, on the coast of Asia Minor (modern day Turkey)
Schools of Thought: Milesian School, Ionians, Naturalism
Other Occupations: Business Owner (Olive Presses), Mathematician, Astronomer

- considered by any to be the first philosopher of the Western tradition and the "father of science", also one of the Seven Sages of Greece.
- recognizes a transcendental God, who has neither beginning nor end.
- believed men are better than women and Greeks are better than barbarians.
- attempted to explain events in the world through nature rather than the gods.
- believed the world originated in water.
- attributed by many to be the first to articulate the idea of "being" (the arche) and "becoming" (the world we see). The arche to Thales was water that made all things.

Some Useful Terms to Know #1

Arche - First articulated in Western Philosophy by Thales, it is the beginning or founding principle of the world (Thales thought it to be water).

Eidos - Used extensively by Plato, this term means form or shape or image.

Teleology - The philosophical study of design, purpose, directive principle, or finality of nature or human creations (of utmost importance to Aristotle).