Against the Milesian Inquiry into Nature and its Ontology

Map of the Ancient World Elea was a Greek city in what is now southern Italy.

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

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

Parmenides is one of the first philosophers in the new philosophical tradition that began with Thales. He was active in the early to the middle part of the 5th century BCE.

Plato (429-347 BCE), in his dialogue Parmenides, indicates that the historical Parmenides visited Athens when Socrates was young and Parmenides himself was about sixty-five. The city of Athens executed Socrates 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 have 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.

"For it is the same, to think and also to be" (DK 28 B 3).

"[The path] which mortals who know nothing invent, two-headed! For the helplessness in their breast directs their wandering thought; and they are borne along, deaf and likewise blind, stupefied, tribes without judgment, who suppose that to be and not to be is the same and not the same, and that for all the path is backward-turning" (DK 28 B 6).

"[M]ortals have established, convinced that they are true, that they are born and are destroyed, are and are not, change their place and modify their bright color" (DK 28 B 8).
"What birth could you seek for it? How, from what could it have grown? Not from what is not—I shall not allow you to say nor to think this. ... It is necessary that it either be completely or not at all. ... That is why Justice has not, loosening its fetters, allowed it either to be born or to be destroyed, but holds it fast. The decision on these matters depends upon this: 'is' or 'is not'? Well, it has been decided, as is necessary, to abandon the one as unthinkable, unnameable (for it is not the true road), and thereby that the other, by consequence, exists and is real. ... In this way birth is extinguished, and destruction is unknowable" (Parmenides, DK 28 B 8).

An Analysis of the Reasoning

It is not easy to see just what Parmenides is thinking, but his arguments for the conclusions

• "birth [coming into existence] is extinguished"
• "destruction [going out of existence] is unknowable"

seem to proceed by the method of proof (that became known in Latin as) reductio ad absurdum. If this is correct, and if the conclusions are that nothing comes into or goes out of existence, then the proof against "birth" takes the following form: reductio, "a leading" ad, "to" absurdum, "absurdity"

In Gentzen style natural deduction, reductio ad absurdum has the following form
----------------- ¬Introduction, 1
   ¬ assumption

• Assume that some object o comes into existence.
It follows from this assumption that "is not" is true of o before it comes into existence.
This consequence, however, is absurd: "is not" cannot be true of anything.
Hence, contrary to the assumption, nothing comes into existence.

The proof against "destruction" proceeds in almost the same way:

• Assume that some object o goes out of existence.
It follows from this assumption that "is not" is true of o after it goes out of existence.
This consequence, however, is absurd: "is not" cannot be true of anything.
Hence, contrary to the assumption, nothing goes out of existence.

In each proof, the conclusion follows if the consequence deduced from the assumption is absurd. The problem is that it is not clear that this consequence is absurd. Parmenides explains why "is not" cannot be true of anything, but his explanation is too obscure to be persuasive.

The New Discipline of Philosophy

It is hard to understand his explanation, but it is clear that Parmenides works in the new discipline of philosophy. He argues for this view about "birth" and "destruction" in a way that does not presuppose any shared beliefs other than those necessary to understand "is" and "is not," which he regards as "the only roads of investigation for thought" to take.

"What are the only roads of investigation for thought: the one, that 'is,' and that it is not possible that 'is not,' is the path of persuasion (πειθοῦς), for it accompanies truth. The other, that 'is not,' and that it is necessary that 'is not'— I show you that it is a path that cannot be inquired into at all. For you could not know that which is not (for this is impracticable [in that it is not be accomplished]). Nor could you show it [by pointing it out]" (DK 28 B 2).

Knowledge, Reason, Experience

Further, Parmenides has an explanation for why human beings believe that things come into and go out of existence even thought "reason" shows this to be impossible. He thinks that although human beings should form their beliefs about existence in terms of reason, the much more common way for them to think about things is in terms of "experience." Reason reveals how reality is, but the habit of relying on experience is ingrained in human beings.

"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 rely on "refutation" 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, and cross-examine (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).

An ἔλεγχος is an "argument of disproof" or "refutation."

Parmenides says that his "refutation" is "much disputed." There is no record of this dispute, so presumably he means that the many (who rely on "experience" for their beliefs) have beliefs inconsistent with his "refutation."
"But as for you, keep your thought away from this road of investigation [that things that are not are]. And do not let much-experienced habit (ἔθος πολύπειρον) force you down onto this road to wield an aimless eye and an echoing ear and tongue. No, by reason judge (κρῖναι δὲ λόγῳ) the much-disputed refutation (ἔλεγχον) spoken by me" (DK 28 B 7).

It can be tempting to think 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 tradition of trying to understand the states and processes in the mind. This tradition continues through Plato (most famously in what has come to known as his Tripartite Theory of the Soul) and throughout most of the ancient philosophical tradition.

The Mistake the Milesians Make

It is in terms of the distinction between the thinking that constitutes "reason" and "experience" that Parmenides seems to criticize Thales and the Milesian inquirers into nature.

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."

To explain what "experience" reveals (when it results in the belief that it is raining, that water droplets are forming in the sky and falling to the ground), 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, he 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.

This explanation cannot be right, according to Parmenides, because it would follow that drops of water come into and go out of existence and "reason" shows that this is impossible.

Perseus Digital Library:

Henry George Liddell, Robert Scott, A Greek-English Lexicon:
αἰσθάνομαι, aisthanomai, verb, "to perceive, apprehend by the senses"
αἴσθημα, aisthēma, noun, "that which is perceived"
αἴσθησις, aisthēsis, noun, "sense-perception"
αἰσθητός, aisthētos, adjective, "sensible, perceptible" (opposed to νοητός, "thinkable")

-μα is added (Smyth, 861) to verbal stems to form neuter nouns denoting the result of an action.
αἰσθάνομαι "perceive" → αἴσθημα "that which is perceived"     νοέω "think" → νόημα "that which is thought"

-τός is added (Smyth, 472) to verbal stems to form verbal adjectives (adjectives derived from verbs) that express possibility (or have the meaning of a perfect passive participle).
αἰσθάνομαι "perceive" → αἰσθητός "perceivable"     νοέω think → νοητός "thinkable"

ἔλεγχος, élenchos, noun, "argument of disproof" or "refutation"
ἐλέγχω, elenchō, verb, "treat a speech with contempt, cross-examine, question"

"I shall... cross-examine (ἐλέγξω) him..." (Plato, Apology 29d).

εμπειρία, empeiria, noun, "experience"
ἐπιστήμη, epistēmē, noun, "knowledge"
δόξα, doxa, noun, "belief"
κρίνω, krinō, verb, "separate, distinguish, discriminate"
κρίσις, krisis, noun, "separating, distinguishing"
κριτικός, kritikos, adjective, "ability to discern"

Aristotle thinks that all animals have the capacity to "discriminate," that in non-human animals and children this capacity takes the form of perception and to some extent experience, and that in adults it also occurs in the form of reason.

"[All animals] have an innate faculty of discrimination (δύναμιν σύμφυτον κριτικήν), which we call perception" (Aristotle, Posterior Analytics II.99b).

λόγος, logos, noun, "reason"
Πειθώ, Peithō, name, the goddess "Persuasion"
πειθώ, peithō, noun, appellative of Πειθώ, "the faculty of persuasion, winning eloquence, persuasiveness"
πείθω, peithō, verb, "persuade"
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,

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