What will appear here are first drafts we have written, which will be in a continual process of revision, most of the early chapters of which are Thomas' work. This one is on the Presocratics:
The Milesians and Pythagoras
Very few of the writings of those philosophers that came before Socrates still exist today. Most of what we know about the Presocratics comes from summaries from other writers in later times, or from small fragments that have survived. Nevertheless, the Presocratic philosophers (so called because they lived before Socrates) can be known fairly well through indirect sources. If nothing else, they influenced the more famous and better understood philosophers that we will spend the next few chapters with.
According to tradition, Western philosophy was born with Thales, an Ionian thinker. Thales won renown for both his great knowledge and his self-imposed poverty. By his poverty he showed that he prized wisdom over wealth. He was also perhaps the first to give philosophy a reputation for being blind to everyday things. Plato tells us that once Thales was walking while doing astronomy and fell into a well to the amusement of those around him, not seeing what was directly in front of him. Whatever Thales' personal quirks may have been, he seems to have been the first person to inquire into the nature of the world in a philosophic, scientific way.
At the time of Thales, and indeed until much later, philosophy was not something distinct from science. In fact, science can also be called "natural philosophy". Thales tried to explain the things around him by observing the things of nature and proposing a theory that made sense of things. He theorized that everything was in fact made up of one sort of substance that could take on any shape or attribute. By proposing a single kind of "stuff" that everything was made out of, Thales was trying to uncover the basic nature of the universe. Thales believed that the truth about the world would show up when one investigates it through reason and observation.
What sort of stuff could take on any shape or quality? Thales believed water was the likeliest possibility. After all, we know that water can be hard when made into ice, fluid when a liquid at room temperature, and almost like the air when it turns into steam. Water can be hot or cold; it can be hard or soft. Perhaps water can take on any attribute or appearance; perhaps people and trees, rocks and stars are made up of water.
Thales' students agreed that everything could be explained by discovering what sort of basic material things were made out of, but they disagreed about what that material might have been. Anaximander believed water to be too specific a thing to be able to be made into anything. Instead, he proposed that all things were made out of the "indeterminate". The "indeterminate" is simply a material that has no qualities in itself, but can take on any quality when is shaped into a particular thing. It cannot be pictured in the mind, because every picture already has a definite appearance (color, shape, etc.), and so we cannot really even imagine what it might be like.
Anaximander's student, Anaximines, thought that Anaxamender correctly criticized Thales, but went too far in the other direction. He proposed that everything is made of of air, which he thought of as something like mist. The air can become more dense and solid, or it can become less dense and more rarefied.
While the Milesians (the name for Thales, Anaximander, Anaximines, and their followers) attempted to explain the world in terms of the material "stuff" that it was made out of, Pythagoras and his followers believed the world was best explained mathematically. Pythagoras realized that music could be broken down into mathematical ratios, and theorized that the cosmos itself could be understood mathematically. The surprising regularity of mathematical patterns in nature suggested that perhaps all of nature could be understood in terms of numbers. Pythagoras developed mathematics in order to expose the hidden structure of the world. For Pythagoras and his followers, mathematics was not a purely academic exercise, but a religious one as well. The relation of numbers to reality was at once surprising and mysterious. If space permits, I might explain the even and the odd; or else the religious/academic split -Thomas
Heraclitus and Parmenides
Heraclitus is perhaps the most interesting of the Presocratic philosophers. Unlike the Milesians and the Pythagoreans, he had little interest in establishing a "school", nor did he seem to believe much in precision in argument. His view of human beings as a whole was a dark one. Once he commented that the common people, rather than pursuing wisdom, "stuff themselves like cattle" (4). Even his views of fellow thinkers was rarely kind. For example, he insulted Pythagoras for having much learning, but no insight (14).
His most interesting views do not concern his distaste for other people, but his descriptions of change. While the Milesians looked for the one same substance that all things are made out of, and while the Pythagoreans set out the immortal laws of mathematics that the universe obeys, Heraclitus focused on how the world was never the same. He famously observed that a person never steps in the same river twice. This observation isn't obvious at first, and so we should think in detail about it.
Imagine Heraclitus standing on a bridge over a river, drawing water out of the river with a bucket. He dyes the water red, and pours it back into the river. After a moment, he draws up his bucket again. The water he draws up now, from the same spot, would not be colored by the dye, and so this bucket of water is different than the last bucket. The water in a river never stays in one place. Even the shape of a river constantly changes. Rivers overflow their banks, they dry out, they are altered by dams, they surge wildly then move along peacefully. Thus, as Heraclitus says, "Upon those who step into the same rivers, different and again different waters flow" (61).
Heraclitus believes that the whole universe constantly changes, not just rivers. Everything moves and flows and changes without rest. Some things change slowly, such as the erosion of rocks, some quickly, such as rivers or fires. Heraclitus likened the universe to a flame burning, always moving, dancing, and jumping in every part. However, at the same time, the flame is still in some sense the same. After all, we might look at the flame of a match until it burns out, and it seems as though the flame, though it moves, is still the same flame. Similarly, the Nile river, though it always moves, still is always the Nile. Things change and yet they remain the same.
Heraclitus pictures the universe in this contradictory way, as always the same and never the same, as constantly in motion and constantly still. In Heraclitus' words: "We step into and we do not step into the same river. We are and we are not" (63). The tension between opposites belongs to the nature of the universe itself. Heraclitus did not feel the need to find a way around these conflicts.
Parmenides, like Heraclitus, tried to understand the way in which the universe changes or remains the same. Unlike Heraclitus, he was not as comfortable with thinking of the universe as inherently contradictory. Parmenides declares that the cosmos is one and unchanging, and that the continuous change and the individual things Heraclitus spoke of is an illusion.
Why would he say this? If we look around it certainly seems as though different kinds of things exist, and it seems that these things move. Further, Parmenides' teaching runs contrary to philosophic tradition, for what the natural philosophers were trying to explain was why different things exist and what they are made out of. Parmenides seems to explain away what other philosophers tried to explain. In order to understand why, we must look at his argument.
Nothing comes from nothing, Parmenides argued. As soon as we speak of a cause of something, we speak of that cause as though it exists. A non-existent cause is simply not a cause. When something comes into being or when it changes, something that did not exist now exists. What is a person before they are conceived? Therefore, when change or coming into being happens, something comes from nothing. However, we know this to be false. Therefore, change does not happen. Things do not come into being. All that exists has always existed without any kind of change.
Parmenides' argument contradicts what we think we see. Should we regard things that change as an illusion? Some philosophers, such as Aristotle, commented that it is not worth talking to those who reject what is most obvious. Yet even Aristotle found it necessary to refute Parmenides' argument in detail in his Metaphysics.