Mythological Explanations
There are various Greek myths to explain the origins of the universe and of man. Three generations of immortal creatures vied for power. The first were personifications of such things as Earth and Sky, whose mating produced land, mountains, and seas. One Greek mythological concept of man tells of an earlier, happier time -- a Greek Garden of Eden.
Pre-Socratic Explanations of the Universe
One idea the Pre-Socratic philosophers had was that there was a single underlying substance that held within itself principles of change. This underlying substance and its inherent principles could become anything. One candidate for the substance was water. Within water there might be such principles as evaporation and condensation, so it could become gaseous or solid. However, there were problems with considering water the underlying principle. Air was another contender. Heraclitus thought it was fire.Atomist and Pluralist Philosophies
From such revolutionary, if problematic ideas, they came up with the idea that the underlying substance must be very small, like an atom. Another idea was that there wasn't a single underlying substance, but several elements, specifically, earth, air, fire, and water, which were associated by the medical followers of Hippocrates with the four humors of the body. In varying proportions, these four elements were thought to have created everything in the world.While we may laugh at these ideas, they are not really that different from modern science which posits atoms and quarks, etc. as the underlying building blocks of matter, and the periodic table of the elements.
Expanding Focus of Philosophy
In addition to looking at the building blocks of matter, the early philosophers, some of whom were actually poets forcing their observations into the strict dictates of poetic meter (try explaining the world around you in Haiku), looked at the stars, music, and number systems. Numbers were used for counting and measuring. Measuring was made of distances on earth, around the earth, or to heavenly bodies. The study of the measure of earth is geo- (earth) + metry (measure). Thales of Miletus (fl. 1st quarter of the 6th century) is credited with bringing geometry to Greece from Egypt, where it was implicit in the construction of the pyramids.Pythagoreans
Probably the most famous of the early Greek philosophers from Ionia (known collectively as the Pre-Socratics) is the 6th century B.C. philosopher Pythagoras, who may have actually lived and may have invented the theorem named for him -- or not. The Pythagorean Theorem says that the square of/on the hypotenuse equals the sum of the squares of/on the two sides, but what Pythagoras would have demonstrated is not something complicated involving a square roots table. Instead, he would have shown that if you position 3 squares of specific dimensions so that they form a right triangle in their center, there is a sum of squares relationship between the hypotenuse and the other two sides.Not all squares put together will produce this remarkable arrangement. It depends on the relationship between the length of a side of each of the three squares. There are other numbers that behave oddly. The Pythagoreans deduced that certain numbers have special properties.
Incidentally, a 3rd century B.C. Greek mathematician, Eratosthenes, living in Alexandria, Egypt (the site of the famous library) used geometry to estimate (reasonably well) the circumference of the earth. His measurement presumes a spherical globe, contrary to any medieval idea of a flat world.
- Pythagorean Numbers
- Pythagorean Theorem
- Philolaus - Pythagorean Philosopher
- Libraries of the Ancient World
- Stoic Philosophy
- How Can I Be Happy? A Stoic and Epicurean Perspective - Guest Feature
- How To Live Like an Epicurean
- Epicurus and His Philosophy of Pleasure
- Ataraxia
- Boethius and the Consolation of Philosophy
Our knowledge of the Pre-Socratic philosophers comes from fragments of their works included in the writing of others. The Presocratic Philosophers: A Critical History with a Selection of Texts, by G.S. Kirk and J.E. Raven provides these fragments in English.
Diogenes Laertius provides biographies of the Pre-Socratic philosophers: Lives of Eminent Philosophers, Loeb Classical Library.


