What Aristotle attributes to Socrates — and what it means

The passage (Metaphysics 1078b17–31)

Aristotle, in his history of the theory of Forms (εἴδη / ἰδέαι), writes:

Σωκράτους δὲ περὶ τὰς ἠθικὰς ἀρετὰς πραγματευομένου καὶ περὶ τούτων ὁρίζεσθαι καθόλου ζητοῦντος πρώτου… δύο γάρ ἐστιν ἅ τις ἂν ἀποδοίη Σωκράτει δικαίως, τούς τ' ἐπακτικοὺς λόγους καὶ τὸ ὁρίζεσθαι καθόλου· ταῦτα γάρ ἐστιν ἄμφω περὶ ἀρχὴν ἐπιστήμης.

"Socrates occupied himself with the ethical virtues and was the first to seek to define them universally… For there are two things one could justly attribute to Socrates: inductive arguments (τούς τ' ἐπακτικοὺς λόγους) and universal definition (τὸ ὁρίζεσθαι καθόλου). For both of these concern the starting-point of knowledge."

(Aristotle, Metaphysics, Eulogikon: hgw-bj, ref. Metaph.1078b)

The framing is explicit: both have to do with the starting-point of knowledge (περὶ ἀρχὴν ἐπιστήμης). The question is — what exactly are these two things, and why do they matter together?

1. What are "inductive arguments" (ἐπακτικοὶ λόγοι)?

The term ἐπακτικοὶ λόγοι means "arguments that proceed by bringing-toward" — reasoning that gathers several particular cases and draws a general conclusion from them. Socrates is famous for doing precisely this in Plato's early dialogues: asking "What is courage?" by collecting examples (courage in battle, courage in facing illness, courage in facing poverty) and testing whether a proposed definition holds for them all.

Aristotle defines the procedure in his own Topics (108b):

Ἡ δὲ τοῦ ὁμοίου θεωρία χρήσιμος πρός τε τοὺς ἐπακτικοὺς λόγους… διότι τῇ καθ' ἕκαστα ἐπὶ τῶν ὁμοίων ἐπαγωγῇ τὸ καθόλου ἀξιοῦμεν ἐπάγειν· οὐ γὰρ ῥᾴδιόν ἐστιν ἐπάγειν μὴ εἰδότας τὰ ὅμοια.

"The study of likeness is useful for inductive arguments… because by induction of the particular cases among similars we claim to bring in (ἐπάγειν) the universal; for it is not easy to induce without knowing the similars."

(Eulogikon: hgw-cd, ref. Top.108b)

The word ἐπαγωγή ("induction") literally means leading or bringing toward. It is a movement: you take the scattered particular cases and lead them together toward a single shared shape (εἶδος). The conversational form Socrates gave it — question and answer, testing examples against proposed definitions — is the practical enactment of this logical procedure.

In the Nicomachean Ethics (1139b), Aristotle states this as a general principle of his own system:

ἡ μὲν δὴ ἐπαγωγὴ ἀρχή ἐστι καὶ τοῦ καθόλου… ἐπαγωγὴ ἄρα.

"Induction is the starting-point of the universal as well… therefore induction [supplies the starting-points of knowledge]."

(Eulogikon: hgw-aw, ref. EN 1139b)

The full argument at 1139b runs: induction is the starting-point of the universal; demonstration proceeds from universals; therefore induction supplies the starting-points that demonstration requires. This places induction prior to demonstration — not a parallel path to knowledge but the act that makes demonstration possible at all. So when Aristotle credits Socrates with ἐπακτικοὶ λόγοι, he is attributing to him the very procedure by which, in his own epistemology, all knowledge begins.

2. What is "universal definition" (τὸ ὁρίζεσθαι καθόλου)?

τὸ ὁρίζεσθαι καθόλου means "defining universally" — giving an account (λόγος) that marks out what something is in every case, not just in this or that instance. The key word is ὁρίζεσθαι: to bound, to mark a boundary, to delimit. A definition (ὁρισμός) sets the limit of a thing — it says where it begins and ends, what it includes and excludes.

Aristotle says Socrates was the first (πρώτου) to seek this systematically, and he did so specifically in the domain of ethics (περὶ τὰς ἠθικὰς ἀρετάς). The commentator Alexander of Aphrodisias adds that earlier thinkers — the Pythagoreans — had given definitions too (e.g., defining justice as a square number), but they did so μαλακῶς ("softly," loosely) and without method, whereas Socrates sought the systematic τί ἐστι, the "what-it-is" of each thing.

(Eulogikon: reo-ae, ref. in Metaph 740–741)

Socrates' innovation was asking: not "What is this particular beautiful thing?" (τόδε τὸ καλόν), but "What is the beautiful itself, across all its instances?" (τί τὸ καλόν ἐστι καθόλου). This search for the universal as such, pursued methodically through question and answer — that is what Aristotle credits him with.

3. Why these two together?

ταῦτα γάρ ἐστιν ἄμφω περὶ ἀρχὴν ἐπιστήμης

"For both of these concern the starting-point of knowledge."

(Aristotle, Metaphysics, Eulogikon: hgw-bj, ref. Metaph.1078b)

Here is why they go together:

• Ἐπαγωγή (induction / leading-toward) is the movement by which we arrive at a universal from the many particular cases. It supplies the content — the shared shape that the instances have in common.
• Ὁρισμός (definition / bounding-off) is the act that fixes that universal — it marks out what the thing is, giving it boundaries so it can be held steady for further reasoning.

Induction is the motion toward; definition is the fixing of what has been reached. Together they form the two moments of how knowledge gets started: first you gather the many into a single seeing, then you bound that seeing so that reasoning can proceed from it.

Alexander of Aphrodisias explains why definitions were so crucial for Socrates specifically:

διὰ δὴ τὸ μὴ εἶναι ἰσχὺν διαλεκτικῆς ἐζήτει πάντων ὁρισμοὺς λαμβάνειν.

"Because the strength/power (ἰσχύς) of dialectic did not yet exist, he sought to obtain definitions of everything."

(Eulogikon: reo-ae, ref. in Metaph 741)

In other words, Socrates lacked the advanced technique of arguing from opposed positions without fixed definitions — the method Plato would later develop in his dialogues. Without a definition to hold onto, you could argue that pleasure is good and also that pleasure is bad, and get nowhere. Definitions gave Socrates a stable place to stand — an ἀρχή (starting-point) from which argument could proceed.

4. The crucial caveat: Socrates did not posit separate Forms

ἀλλ' ὁ μὲν Σωκράτης τὰ καθόλου οὐ χωριστὰ ἐποίει οὐδὲ τοὺς ὁρισμούς· οἱ δ' ἐχώρισαν, καὶ τὰ τοιαῦτα τῶν ὄντων ἰδέας προσηγόρευσαν.

"But Socrates did not make the universals separate (χωριστά), nor the definitions; whereas they separated them, and called such things Forms (ἰδέας)."

(Aristotle, Metaphysics, Eulogikon: hgw-bj, ref. Metaph.1078b)

This is the decisive distinction, and the single word χωριστά — separate — carries it all. Socrates' universal was immanent — it lived in the particulars, as the common nature shared by all courageous acts. It was a tool for inquiry, not a separate entity.

Plato and the Platonists took the same universals and separated them (ἐχώρισαν) from the sensible world, turning them into independently existing Forms (ἰδέαι). This separation — not the search for definitions itself — is what Aristotle criticises.

And Aristotle's critique is sharp:

ὥστε συνέβαινεν αὐτοῖς σχεδὸν τῷ αὐτῷ λόγῳ πάντων ἰδέας εἶναι τῶν καθόλου λεγομένων, καὶ παραπλήσιον ὥσπερ ἂν εἴ τις ἀριθμῆσαι βουλόμενος ἐλαττόνων μὲν ὄντων οἴοιτο μὴ δυνήσεσθαι, πλείω δὲ ποιήσας ἀριθμοίη· πλείω γάρ ἐστι τῶν καθ' ἕκαστα αἰσθητῶν ὡς εἰπεῖν τὰ εἴδη.

"So it turned out for them that there are Forms of practically everything that is said universally — much like someone who, wanting to count, thinks he cannot when the items are few, but makes them more numerous and then counts; for the Forms are more numerous, so to speak, than the particular sensible things."

(Aristotle, Metaphysics, Eulogikon: hgw-bj, ref. Metaph.1078b)

The critique: the Theory of Forms multiplies entities rather than reducing them. You start with particulars needing explanation, and instead you end up with particulars plus their separate Forms — more things to account for, not fewer.

Summary