Greek philosophy didn’t begin in Greece (as we know it); It began on the western coast of what is now Turkey, an area known then as Ionia. In Ionia’s richest city, Miletus, was a man of Phoenician descent called Thales (624-546). He studied in Egypt and other parts of the near east, and learned geometry and astronomy.

His answer to the great question of what the universe is made of was water. Inasmuch as water is a simple molecule, found in gaseous, liquid, and solid forms, and found just about everywhere, especially life, this is hardly a bad answer! It makes Thales not only the nominal first philosopher, but the first materialist as well. Since ultimate nature was known in Greek as physis, he could also be considered the first physicist (or, as the Greeks would say, physiologist).

We should note, however, that he also believed that the whole universe of material things is alive, and that animals, plants, and even metals have souls -- an idea called panpsychism.

His most famous student was Anaximander (611-549), also of Miletus. He is probably best known as having drawn the first known map of the inhabited world, which probably looked something like this:

Anaximander added an evolutionary aspect to Thales’ materialism: The universe begins as an unformed, infinite mass, which develops over time into the many-faceted world we see around us. But, he warns, the world will eventually return to the unformed mass!

Further, the earth began as fluid, some of which dries to become earth and some of which evaporates to become atmosphere. Life also began in the sea, only gradually becoming animals of the land and birds of the air.

Like Thales, Heraclitus (540-475) was an Ionian, from Ephesus, a little north of Miletus. And, like Thales, he was searching for the ultimate substance that unifies all reality. He decided on fire, or energy -- again, not a bad guess at all.

The multiplicity of reality comes out of fire by condensation, becoming humid air, then water, and finally earth. But this is balanced by rarefaction, and the earth liquifies, then evaporates, and finally returns to pure energy.

Taking fire as his ultimate substance led to a more dynamic view of reality. Change, for Heraclitus, is the only constant. “Panta rhei, ouden menei” -- all things flow, nothing abides -- is his most famous saying. He is also known for the saying that we cannot step into the same river twice, because new water is constantly flowing onto us.

Fire is also associated in his theory with mind or spirit. And, just like any other fire, he points out that our individuality eventually dies. There is no personal immortality. Only God -- the divine fire -- is eternal.

In many ways, Heraclitus reminds me of a Greek Taoist. He believed that, although ultimate reality is One, the world we know is made of up dualities, with each pole requiring the existence of its opposite: Up requires down, white requires black, good requires bad, and so on.

And he sees these oppositions as being the source of harmony, pointing out that, unless you stretch your harp strings in two opposing directions, you cannot play music.

And, again like the Taoists, he believed that the best way to live one’s life is in harmony with nature. But he died alone, at the age of 70, due to his intense dislike for human company!