Parmenides of Elea

Parmenides of Elea

Parmenides looked at the world we all live in, the world of birth and growth and motion and a thousand separate things, and concluded, on the strength of a single argument, that almost none of it is real. What truly is, he decided, is one, eternal, indivisible, and changeless. Nothing is ever born; nothing ever ends; nothing moves; there is no genuine plurality at all, only one unbroken being. It is the most violently counterintuitive claim in the history of philosophy, and the point is not whether Parmenides was right. The point is that he was the first person in the West to trust an argument over the plain evidence of his own eyes, and to refuse to flinch when it carried him somewhere no sane person wanted to go. That refusal is where philosophy as a discipline of reason begins. And he delivered it, strangely, in the least logical of forms: a poem in the Homeric meter of epic, spoken in the voice of a nameless goddess who receives a young man at the end of a chariot ride, at the gates where the paths of Day and Night divide.

The two roads. The argument begins from something that sounds too obvious to be worth saying: that what is, is, and what is not, is not. The goddess sets out two roads a mind can travel. The first says of its object that "it is, and cannot not be," and this is the road of truth. The second says "it is not, and must not be," and this road, she warns, goes nowhere, because you cannot so much as think it. Try to think of what is not, of sheer nothing, and you find you are thinking of something after all; the mind is left with nothing to take hold of. To speak of what-is-not is to speak of nothing, which is not to speak at all. So one road closes before you have set out on it, and only the road of what-is remains open. It looks like a tautology dressed up in epic verse. It is about to take the world apart.

What follows, and it is everything. Hold to that one premise and follow it without mercy, which is the thing no one before Parmenides had dared to do. Could what-is ever have come into being? It could only have come out of what-is-not, and there is no what-is-not for it to come from; so no, it is ungenerated. Could it ever perish? Only by passing into what-is-not, which again does not exist; so no, it is undying. Could it be divided into parts? Only if gaps of what-is-not lay between them, and there are no such gaps; so it is one, whole, and continuous. Could it move? Motion needs an empty elsewhere to move into, a stretch of what-is-not, and there is none; so it does not move. Step by careful step, the single innocent premise strips reality of birth, death, division, and motion, until all that remains standing is one changeless being, complete and entire, which Parmenides compares to a perfectly rounded sphere. Every step in the chain is valid. The conclusion contradicts everything you have ever seen. That is the scandal he set down in the middle of Greek thought, and no one could simply walk around it.

Zeno's knife. His student Zeno came to the master's defense with a brilliant flank attack: rather than prove the One over again, he showed that the opposite view, that motion and plurality are real, collapses into absurdity. Before swift Achilles can overtake the tortoise that started ahead of him, Zeno argued, he must first reach the point where it began; but by then the tortoise has moved on a little; Achilles must reach that new point, and again the tortoise has crept ahead, and the gap divides forever, so the fastest runner can never catch the slowest crawler. Before you can cross a room you must cross half of it, and before that half, half of the half, and the halvings never come to an end, so the journey can never even begin. An arrow in flight, at any single instant, fills a space exactly its own length and is therefore at rest; and if it is at rest at every instant of its flight, when does it ever move? These were not riddles for amusement. They were the first deliberate use of argument driven to absurdity, the reductio, and they kept mathematicians busy for twenty-four centuries. The calculus learned to sum the infinite halvings and gave the practical answer, but the deep puzzle, how an endless division can add up to a single ordinary step, has never entirely lost its sting.

The world we have to live in. Parmenides was no fool, and he knew the world plainly seems to move and change. The second half of his poem, the Way of Opinion, lays out a complete cosmology, a universe woven from light and night and the wheeling of the heavens, the best account a mortal could give of the world of appearances, and he marks it for exactly what it is: opinion, not truth. Readers have argued ever since over whether he offered it as an honest second-best or as an elaborate decoy. But the move that mattered was the division itself. Parmenides drew the first sharp line in the West between the way things really are and the way they appear to us, between a reality that reason can reach by argument and a show that the senses merely report. Once that crack opens, it never closes. The whole long enterprise of philosophy, and eventually of science, pours through it, carried by the conviction that the truth of things may lie underneath or behind what we perceive, and that thought, not the eye, is what reaches it.

Follow the argument. The room reads the fragments in John Burnet's old public-domain translation, cited by their Diels-Kranz numbers, so a line like DK B8 points to the deductive core itself. What Parmenides models, and it is the most uncomfortable discipline in all of thinking, is the willingness to follow an argument to exactly where it leads, even when it lands somewhere you cannot bring yourself to believe. Most of us, arriving at an absurd conclusion, quietly decide we must have slipped somewhere and let the matter drop. Parmenides did the reverse, and in doing so he forced every philosopher after him into a stark choice: find the flaw in the argument, or accept its impossible result. That pressure is one of the great engines of philosophy, and the tradition is in large part a series of answers to him. The atomists invented empty space on purpose, to give motion the patch of what-is-not it needed. Plato's Sophist showed that "is not" can mean "is different from" rather than "is nothing," loosening the knot at its tightest point. Aristotle broke the deadlock with potentiality and actuality, a way for a thing to become what it is not yet without conjuring it out of sheer non-being. Each was a door cut through the wall Parmenides had built, and the building of the wall came first.

The racehorse at the gate. There is a real case to be made that the most stirring moment in the entire history of philosophy is a quiet one, tucked into a difficult dialogue of Plato's, and that it belongs to Parmenides in his old age. Plato almost certainly arranged the scene himself, but it is worth telling anyway. The aged Parmenides comes to Athens and falls into conversation with a very young Socrates, who lays out his first, raw version of the theory of Forms. The old man takes it apart, gently and completely, exactly as he would take apart anything not yet thought all the way through. But he does not send the boy away. He tells him that the impulse driving him toward argument is noble and divine, and that what he lacks is only training, the discipline of following a question through every last one of its consequences. The others press Parmenides to show them how that is done. He hesitates, pleading his age; he says he feels like the old racehorse in the poem, who trembles at the starting line because he knows from long experience exactly what the race is about to cost him. And then, trembling, he runs it anyway. He undertakes the most grueling dialectical exercise in the whole Greek corpus, the long examination of the One and all its consequences, and he performs it in front of the young Socrates so that the boy can watch the method actually done. Consider what is happening in that room. The first person ever to trust pure reasoning over the senses, in his old age and dreading the labor of it, spends himself to demonstrate the method for the one young listener he has decided is worth the ordeal. And consider who that listener is. If Socrates really is the source the tradition takes him for, the figure from whom Plato, and so most of Western philosophy, descends, then this quiet scene may be one of the genuine hinges of intellectual history: the moment the discipline of following reason wherever it leads was handed on, deliberately and at real cost, to the one mind that would carry it furthest. The old man dreaded the race and ran it anyway, because he had seen something in the boy. If he was right about Socrates, the whole river may begin here.

The argument never really died; it only changed its clothes. When Hegel opened his Logic with the emptiest thought a mind can hold, pure Being, and watched it pass over into Nothing and settle into Becoming, he was beginning exactly where Parmenides began, and letting Heraclitus answer back. When Einstein's relativity spread time out into a single four-dimensional whole in which nothing genuinely comes to be or passes away, more than one philosopher heard the old Eleatic again, the changeless sphere of being in modern dress, set against the Heraclitean world of flow. Twenty-five centuries after a man in a small Greek colony wrote a poem arguing that motion is impossible, the quarrel he opened, between the reality that reason can prove and the change the senses will not stop insisting on, is still among the deepest questions we have about what is real. Parmenides did not settle it. He was the first to see that it could be argued at all, and that, more than any conclusion, is what he left us.