Sophie's World: A Novel About the History of Philosophy by Jostein Gaarder Read Free Book Online

all believed in the existence of a single basic substance as the source of all things. But how could one substance suddenly change into something else? We can call this the problem of change.

    From about 500 B.C., there was a group of philosophers in the Greek colony of Elea in Southern Italy. These "Eleatics" were interested in this question.

    The most important of these philosophers was Parmenides (c. 540-480 B.C.). Parmenides thought that everything that exists had always existed. This idea was not alien to the Greeks. They took it more or less for granted that everything that existed in the world was everlasting. Nothing can come out of nothing, thought Parmenides. And nothing that exists can become nothing.

    But Parmenides took the idea further. He thought that there was no such thing as actual change. Nothing could become anything other than it was.

    Parmenides realized, of course, that nature is in a constant state of flux. He perceived with his senses that things changed. But he could not equate this with what his reason told him. When forced to choose between relying either on his senses or his reason, he chose reason.

    You know the expression "I'll believe it when I see it." But Parmenides didn't even believe things when he saw them. He believed that our senses give us an incorrect picture of the world, a picture that does not tally with our reason. As a philosopher, he saw it as his task to expose all forms of perceptual illusion.

    This unshakable faith in human reason is called rationalism. A rationalist is someone who believes that human reason is the primary source of our knowledge of the world.

    All Things Flow A contemporary of Parmenides was Heraditus (c. 540-480 B.C.), who was from Ephesus in Asia Minor. He thought that constant change, or flow, was in fact the mosf basic characteristic of nature. We could perhaps say that Heraclitus had more faith in what he could perceive than Parmenides did.

    "Everything flows," said Heraclitus. Everything is in constant flux and movement, nothing is abiding. Therefore we "cannot step twice into the same river." When I step into the river for the second time, neither I nor the river are the same.

    Heraclitus pointed out that the world is characterized by opposites. If we were never ill, we would not know what it was to be well. If we never knew hunger, we would take no pleasure in being full. If there were never any war, we would not appreciate peace. And if there were no winter, we would never see the spring.

    Both good and bad have their inevitable place in the order of things, Heraclitus believed. Without this constant interplay of opposites the world would cease to exist.

    "God is day and night, winter and summer, war and peace, hunger and satiety," he said. He used the term "God," but he was clearly not referring to the gods of the mythology. To Heraclitus, God--or the Deity--was something that embraced the whole world. Indeed, God can be seen most clearly in the constant transformations and contrasts of nature.

    Instead of the term "God," Heraclitus often used the Greek word logos, meaning reason. Although we humans do not always think alike or have the same degree of reason, Heraclitus believed that there must be a kind of "universal reason" guiding everything that happens in nature.

    This "universal reason" or "universal law" is something common to us all, and something that everybody is guided by. And yet most people live by their individual reason, thought Heraclitus. In general, he despised his fellow beings. "The opinions of most people," he said, "are like the playthings of infants."

    So in the midst of all nature's constant flux and oppo-sites, Heraclitus saw an Entity or one-ness. This "something," which was the source of everything, he called God or logos. Four Basic ElementsIn one way, Parmenides and Heraclitus were the direct opposite of each other. Parmenides' reason made it clear that nothing could change. Heraclitus' sense perceptions