Against the Milesian Inquiry into Nature and its Ontology

Elea was a Greek city in what is now southern Italy.

Xenophanes was born in Colophon, a Greek city of Ionia, in about 570 BCE and to "a very great age" (Diogenes Laertius, Lives the Eminent Philosophers IX.2).

"[Parmenides] was instructed by Xenophanes" (Diogenes Laertius, Lives the Eminent Philosophers IX.3).

Parmenides was active in the early to the middle part of the 5th century BCE.

Plato (late 5th century to 347 BCE), in his dialogue Parmenides, indicates that Parmenides visited Athens when Socrates was was a young man and that Parmenides himself was about sixty-five at the time. Socrates was executed in 399 BCE when he was seventy. If Socrates was twenty when Parmenides visited Athens, then Parmenides was born in about 515 BCE.

The connection between Parmenides and the Milesians is uncertain, but it may have run through Xenophanes. Xenophanes came from Colophon, near Miletus, and he seems to haved moved to southern Italy. Parmenides himself does not mention any of his predecessors by name.

Nothing comes into Existence

What survives from Parmenides are fragments of a poem written in the traditional epic medium of hexameter verse. Parmenides does not identify those he argues against in his poem, but given his argument, it is natural to understand him as arguing against Thales and the inquirers into nature.

Parmenides seems to think that the inquirers into nature are confused about what exists. As he seems to understand them, they think that the objects salient in experience exist in terms of changes in the nature of things. Parmenides argues that this conception is incoherent. He argues that "reason" shows that coming into and going out of existence are impossible.

"Come now, and I will tell, and you, hearing, preserve the story the only routes of inquiry there are for thinking (νοῆσαι); the one, that it is and that it is not possible that it not be (ἔστιν τε καὶ ὡς οὐκ ἔστι μὴ εἶναι), is the way of persuasion (πειθοῦς) (for it attends upon truth), the other, that it is not, and that it is right not to be (οὐκ ἔστιν τε καὶ ὡς χρεών ἐστι μὴ εἶναι), this I point out to you is a way altogether indiscernible: for you could not know (γνοίης) what is not (for it is not to be accomplished) nor could you point it out..." (DK 28 B 2).

"For the same thing is for thinking and for being (τὸ γὰρ αὐτὸ νοεῖν ἐστίν τε καὶ εἶναι)" (DK 28 B 3).

"[The path] on which mortals, knowing nothing, wander, two headed; for helplessness in their breast directs their wandering thought; they are carried along deaf and blind alike, amazed, uncritical hordes for whom to be and not to be are supposed to be the same and not the same, and the path of all is backward-turning" (DK 28 B 6).

"It has been named all the names which mortals have laid down, believing them to be true, coming-into-being and perishing, being and not being, changing place and altering bright color" (DK 28 B 8).
"What birth will you seek for it? How and whence did it grow? I shall not allow you to say nor to think from not being. For it is not to be said nor thought that it is not (οὐ γὰρ φατὸν οὐδὲ νοητόν ἔστιν ὅπως οὐκ ἔστι). And what need would have driven it later rather than earlier, beginning from nothing, to grow? Thus it must either be completely or not all. Nor will the force of conviction (πίστιος) allow anything besides it to come to be ever from not being. Justice has never loosed her fetters to allow it to come to be or to perish, but holds it fast. And the judgment (κρίσις) about these things lies in this: it is or it is not (ἔστιν ἢ οὐκ ἔστιν). But it has been decided, as is necessary, to leave the one way unthought and nameless (for it is no true way), and that the other is and is genuine. And how could what is be in the future? How could it come to be? For if it came into being, it is not: nor is it if it is ever going to be in the future. Coming to be is extinguished and perishing unheard of" (Parmenides, DK 28 B 8).

An Outline of the Reasoning

It is not easy to see just what Parmenides is thinking, but his reasoning seems to take the form of a proof by (what became known in Latin as) reductio ad absurdum:

reductio, "a leading"
ad, "to"
absurdum, "absurdity"

Assume that something, an object o, has come into (gone out of) existence.
It follows that "it is not" is true of o before (after) it came into (went out of) existence.
This is absurd: "it is not" cannot be true of anything.
Hence, contrary to the assumption, nothing comes into (goes out) of existence.

An Analysis of the Reasoning

In this reasoning, the assumption for reductio is that something has come into (or will go out of) existence. The intention is to prove that this assumption leads to an impossibility. From the assumption that some object o has come into existence, it is supposed to follow that o did not exist before it came into existence. This does seem to follow, and this is supposed to be the problem.

It is not very clear, though, just what the problem is. Parmenides seems to think that somehow this is a way of saying of o that "it is not" and that this somehow cannot be true. Parmenides makes suggestive remarks about why this is, but nothing he says is clear enough to be very persuasive given how natural it is to think that things come into and go out of existence.

Knowledge, Reason, Experience

Parmenides has an explanation for why human beings believe that things come into and go out of existence. He thinks that although human beings can form beliefs in terms of "reason," "experience" is the much more common way for them to think about things. Reason reveals how reality is, but the habit of relying on experience for beliefs is hard to break.

"In these verses Parmenides means ... that [the road] they travel is that of investigation according to philosophical reason (τὸν φιλόσοφον λόγον) ... [and that this] reason, like a Divine conductor, points the way to the knowledge of all things" (Sextus Empiricus, Against the Logicians I.112).

Socrates will later rely on "testing" in his love of wisdom. "While I have breath I shall never give up the love of wisdom (φιλοσοφία) or stop exhorting you, charging any of you I happen to meet in my accustomed manner: 'You are the best of men, being an Athenian, citizen of a city honored for wisdom and power beyond all others. Are you not ashamed to care for money, and reputation, and public honor, while having no thought or concern for wisdom and truth and the best state of your soul?' If some one of you disputes this, and says he does care, I shall not immediately dismiss him and go away but shall question, examine, test (ἐλέγξω) him, and if he does not seem to me to possess virtue, and yet says he does, I shall rebuke him for counting of more importance things which by comparison are worthless" (Plato, Apology 29d-30a).
"In no way may this prevail, that things that are not, are. Bar your thought (νόημα) from this way of inquiry, and do not let habit (ἔθος) born from much experience (πολύπειρον) compel you along this way to direct your sightless eye and sounding ear and tongue, but judge by reason (κρῖναι δὲ λόγῳ) the heavily contested testing (ἔλεγχον) spoken by me" (DK 28 B 7).

It can be tempting to think that we know what Parmenides means by "reason" and "experience," at least in part because the words are so familiar to us, but we should not assume that the ancient philosophers conceive of these forms of cognition in the same way we do. Parmenides was an early participant in an ongoing project to understand the states and processes in the mind.

The Mistake the Milesians Make

Thales and the Milesians rely on "reason" in their inquiries into nature. It is through the use of reason that they try to get beyond the traditional stories involving the gods, but, as Parmenides understands them, they also mistakenly rely on "habit born of much experience."

Experience seems to show that sometimes it rains, that sometimes water droplets form in the sky and fall to the ground. To explain what experience shows, Anaximenes uses the new style of explanation that the Milesian inquirers into nature introduced. For Anaximenes, air is the underlying nature. Air is. It is everlasting. It never comes into or goes out of existence. At the same time, Anaximenes conceives of droplets of water as portions of air in a condensed state and thinks that these droplets come into and go out existence with changes in the state of air.

Perseus Digital Library:

Henry George Liddell, Robert Scott, A Greek-English Lexicon:
αἴσθησις, aisthēsis, noun, "sensation,"
ἀλλοφρονέω, allophroneō, verb, "think of other things,"
εμπειρία, empeiria, noun, "experience,"
ἐπιστήμη, epistēmē, noun, "knowledge,"
δόξα, doxa, noun, "belief,"
κρίσις, krisis, noun, "judgment,"
λόγος, logos, noun, "reason,"
πολύπειρος, polypeiros, adjective, "much-experienced,"
φρόνησις, phronēsis, noun, "sensibleness [= the ability to behave sensibly]"

Arizona State University Library. Loeb Classical Library:
Early Greek Philosophy, Volume V: Western Greek Thinkers, Part 2,

move on go back