Thales

THALES  [Miletus, 624-546 BC]

Western philosophy begins in the antiquity roughly at the same time when Western historiographers began to record history more or less systematically. This is of course no surprise. We may believe that earlier philosophers have existed, but their works would have been invariably lost. Historiography was supposedly invented by the Babylonians, before the Greeks, but we shall leave this question to the historians and continue with philosophy.

Try to picture the early Greek civilization around 600 BC. Imagine yourself in a flourishing commercial town at the sunny coast of Ionia. The Greeks traded intensively with each other and with surrounding nations, thus many Greek city states accumulated considerable wealth and with it came art, science, and philosophy. However, there was trouble.

The political climate was afflicting as a consequence of slavery and mercantilism. Greek cities were often ruled by ruthless tyrants - landowning aristocrats and superrich merchants who gave little importance to ethical considerations. Around 585 BC there lived a man in Miletus whose name was Thales, one of the Seven Wise men of Greece.

Thales had traveled to Egypt to study the science of geometry. Somehow he must have refined the Egyptian methods, because when he came back to Miletus he surprised his contemporaries with his unusual mathematical abilities. Thales calculated the distance of a ship at sea from observations taken on two points on land and he knew how to determine the height of a pyramid from the length of its shadow. He became famous for predicting an eclipse in 585 BC.

In spite of his wisdom, Thales was a poor man. The inhabitants of Miletus ridiculed Thales for his philosophy and asked him what his wisdom is good for if it can't pay the rent.

"He was reproached for his poverty, which was supposed to show that philosophy is of no use. According to the story, he knew by his skills in the stars while it was yet winter that there would be a great harvest of olives in the coming year; so, having a little money, he gave deposits for the use of all olive-presses in Chios and Miletus, which he hired at a low price because no one bid against him.

When the harvest time came, and many were wanted all at once and of a sudden, he let them out at any rate which he pleased, and made a quantity of money. Thus he showed the world that philosophers can be rich if they like, but that their ambition is of another sort." [from "Politics", Aristotle]

Thales was a mathematician rather than a philosopher, but in antiquity there was no differentiation between the natural sciences and philosophy; instead, mathematics, philosophy and science were closely related in the works of the early Greek philosophers.

Most people remember Thales for his famous theorem about right angles that says: A triangle inscribed in a semicircle has a right angle (see figure on the left). Although this might seem a simple observation, Thales was the first one who stated it and thus started what is now generally known as "deductive science", the process of deriving suppositions and mathematical statements from observation by means of logic. Circles and angles were not the only objects Thales was concerned with. Purportedly he also studied magnetism and electrostatic effects, however, since none of his own works has survived, we don't know what he may have found out about them.

Thales was surely an exceptional man, but he was not the only thinker in ancient Greece whose thoughts were ahead of his time. For instance, the idea that all forms of substances can be reduced to a few elements and that every form of matter are made of these elements, is essentially Greek, and was conceived around the time of Thales.

Thales stated that the origin of all matter is water. Although this sounds a bit odd, there may be some truth in it. As we know today, the largest constituent of the universe is hydrogen, which makes two of the three atoms in water (H2O). The missing oxygen atom was added later when our planet formed. Scientists believe that liquid water is prerequisite to life, and we know with certainty that the first life forms flourished in the oceans, so water is indeed a primordial substance.

The Greeks also anticipated a crude version of the concept of modern thermodynamics. Anaximander (546 BC), a Milesian citizen who lived after Thales, expressed the following thought: The elements (air, water earth and fire) are in opposition to each other, each perpetually seeking to increase itself in quantity. Due to the resulting struggle for dominance, all forms of matter are subject to continual change. Thus, the elements are constantly transformed into one another, however, without one element ever gaining preponderance over the others because of a natural balance.

Anaximenses (494 BC), the third philosopher of Miletus, refined the theory of the elements later with his original theory of the aggregates: The fundamental substance, he said, is air. The soul is air, fire is rarefied air, when condensed, air becomes first water, then if further condensed, earth, and finally stone. Consequently all differences between different substances are quantitative, depending entirely upon the degree of condensation.

You may find these ideas strange, but it has to be considered that the early Greek philosophers lived in an environment where indigenous beliefs and superstitions prevailed in the spiritual world and the rule of thumb was accepted authority. Thales was the first who made a difference by introducing deductive, scientific thought.

I would like to end this Thales portrait with a peculiar quote, which shows the spiritual Thales. He said: "All things are full of Gods," and left it unexplained.