Socratic Intellectualism (Virtue Is Knowledge)

The thesis, sharpest in the Protagoras, that virtue is knowledge — and its two corollaries: the unity of the virtues (courage, justice, temperance, piety, wisdom are one knowledge, not separable dispositions) and the denial of akrasia ("no one does wrong willingly," oudeis hekōn hamartanei — all vice is ignorance, so "weakness of will" is impossible). If to know the good is to do it, then courage is just knowledge of what is and is not to be feared (Protagoras 360c), and what looks like being "overcome by pleasure" is really a miscalculation curable by an art of measurement. The thesis has a powerful corollary for the Meno's question: if virtue is knowledge, it must be teachable. But it sits in standing tension with the partitioned, appetite-bearing soul of the Gorgias and Republic IV, which re-admit the irrational desire intellectualism denies.

Key Points

Virtue is knowledge: each virtue, pressed, collapses into wisdom/knowledge (Protagoras 330c–333b, 349a–360e); to know the good is sufficient for doing it.
The unity of the virtues: the virtues are not parts-of-a-face (heterogeneous, separable) but a single knowledge under many names — Protagoras resists exactly here, defending courage as separable, and Socrates presses unity.
"No one errs willingly" (oudeis hekōn hamartanei): wrongdoing is involuntary because it rests on ignorance of the good; "no one goes willingly toward the bad" (Protagoras 358d). First smuggled in via the Simonides reading (345d–e), then argued directly.
The denial of akrasia: "being overcome by pleasure" is incoherent if good = pleasant — it would mean being "overcome by the good" (355d); what really happens is misjudgment of magnitude, corrigible by measurement (the Protagoras' metrētikē technē).
The teachability corollary: if virtue is wholly knowledge, "it would be very surprising indeed if virtue could not be taught" (Protagoras 361b) — which is why the intellectualist conclusion overturns Socrates' own opening doubt.

What the Concept Does

Reduces ethics to cognition — makes the moral life a matter of getting the good right, so that vice is error and virtue is expertise; this is what licenses the measuring-art as "salvation in life."
Unifies the virtues under one knowledge — so that one cannot be (e.g.) genuinely brave while unjust, because both would be the same knowledge of good and bad; the parts-of-virtue dispute is settled by collapse into wisdom.
Makes virtue teachable in principle — by making it knowledge, it brings virtue under the model of an expertise that can be transmitted, reframing the Meno's aporia.

What It Rejects

The reality of akrasia / weakness of will — that one can knowingly act against one's better judgment, "overcome" by passion or pleasure (the view of "the many").
The separability of the virtues — that one can have courage without wisdom, or justice without the rest (Protagoras' parts-of-a-face picture).
A motivationally divided soul — irrational desires that oppose knowledge of the good; this is the very thing the Gorgias and Republic IV later restore.

Stakes

Intellectualism is the first term in a developmental arc that the wiki tracks across three dialogues. The Protagoras denies akrasia (no irrational desire); the Gorgias already presupposes an ordered, appetite-bearing soul (the leaky-jar, the kosmos/taxis argument) that re-admits irrational desire; the Republic IV then partitions the soul into rational, spirited, and appetitive parts, making akrasia (the thirsty soul that refuses to drink) the very evidence for tripartition. The Gorgias is the middle term. See claims#plato-moral-psychology-intellectualism-to-partition (live claim). Intellectualism also stakes one of Plato's two non-converging answers to whether virtue can be taught — see claims#plato-virtue-teachability-staged-twice.

Wave 4 widens both the evidence base and the arc's far end. The Euthydemus sharpens the thesis to its strongest form — wisdom is the sole intrinsic good, every other "good" beneficial only by knowledge's right use (the conditional-goods argument, 281d–e); the Apology deploys "no one errs willingly" in an existential-forensic register (death-fear as a false claim-to-knowledge, 29a–b); the Laches and Charmides run "courage / temperance = knowledge" aporetically or as a refutation, not an affirmation (see claims#plato-laches-protagoras-courage-mirror (live claim) and claims#plato-charmides-anticipates-intellectualism (live claim)); and the Laws IX gives the arc's late endpoint — it retains "all wicked men are unwillingly wicked" (860d) yet supplements it with anger (thumos) and pleasure (hēdonē) as independent, non-cognitive sources of wrongdoing alongside ignorance (863a–b). So the corpus neither abandons nor purely holds intellectualism: it supplements it (see punishment-as-cure).

Wave 7 adds the dubia as a distorting mirror. The Hipparchus runs "everyone loves the good" to the eristic parody "everyone is greedy" — even "to blame greed is to be greedy" (232c) — the intellectualist axiom abused by substituting "the good" for a determinate object. The Second Alcibiades both deploys the thesis (no one of sound mind, knowing the best, commits the great crimes, 143d) and complicates it: it concedes that ignorance of particulars can prevent a crime (144c) and that knowledge of means without knowledge of the end is harmful (144d–146d) — a means/ends split pure intellectualism lacks. Both are dubia, so they attest how the Academy handled the thesis rather than evidencing Plato's own view. See claims#plato-dubia-systematize-the-aporetic (live claim).

Problem-Space

The concept addresses the problem of moral failure: if knowing the good were sufficient for doing it, why do people knowingly act badly? Intellectualism's bold answer — they don't; they only ever act on a mistaken view of the good — saves the sufficiency of knowledge at the cost of denying a familiar experience (weakness of will). The Republic's tripartition is the corpus's eventual concession that the experience is real, relocating the problem from ignorance to the soul's internal conflict. (Whether "teachability of virtue" is itself a recurring problem-space awaits a third source under a different vocabulary; for now it is homed here and on the Meno.)

Motif Weight & Corpus Recurrence

Draws on the motif §"craft / technē analogy / craft-knowledge (Plato)" (weight class: STRUCTURAL; the Socratic model of knowledge as a technē with a determinate subject, attested across the Protagoras, Gorgias, Ion, Statesman, Sophist, and — as a limit case — the Hippias Minor). See motifs. Intellectualism applies the craft-analogy to virtue: if virtue is knowledge, it is an expertise with the good as its subject. The Hippias Minor exposes the analogy's breaking point: because a genuine technē is a two-way power (the expert who can produce F can produce not-F at will — the good runner runs slowly on purpose, 373d), modeling virtue on craft entails that "the voluntary wrongdoer is the good man" (376b) — a conclusion Socrates pointedly disavows with a conditional, "if there is such a person" (376b). The exit is the intellectualist thesis: since no one errs willingly, there is no voluntary wrongdoer, so virtue cannot be a neutral two-way capacity. The dialogue thus marks the precise point at which virtue-as-knowledge must break the very craft-analogy it otherwise rides. See claims#plato-hippias-minor-craft-analogy-reductio (live claim).

Connections

is developed by plato-protagoras — virtue = knowledge, the unity of the virtues, the denial of akrasia (the fullest statement).
is strained by plato-gorgias — the ordered-soul psychology that begins to re-admit irrational desire; the middle term toward tripartition. See claims#plato-moral-psychology-intellectualism-to-partition (live claim).
is superseded by tripartite-soul — the Republic IV partition makes akrasia real and intra-psychic, the evidence for a divided soul.
reframes the Meno's question — if virtue is knowledge it is teachable; one of two non-converging Platonic answers. See claims#plato-virtue-teachability-staged-twice.
contrasts with anamnesis — the Meno makes virtue-as-knowledge recollected (and ends with virtue as god-given without understanding); the Protagoras makes it a teachable measuring-expertise — two routes, neither completed.
applies the craft/technē analogy — virtue modeled as an expertise with the good as its subject (see motifs).
is run as a reductio by courage-andreia — the Laches refutes "courage = knowledge of the fearful and the hopeful," the very formula the Protagoras welcomes (see claims#plato-laches-protagoras-courage-mirror).
is run to a reductio by plato-hippias-minor — the Lesser Hippias pushes the craft-analogy of virtue until it yields "the voluntary wrongdoer is the good man" (376b); the paradox dissolves only on the intellectualist premise that there is no voluntary wrongdoer. See claims#plato-hippias-minor-craft-analogy-reductio (live claim).
is anticipated aporetically by temperance-sophrosyne — the Charmides reaches "knowledge of good and evil" (174b) only by elimination, then stops.
is supplemented by punishment-as-cure — the Laws IX adds anger and pleasure to ignorance as independent sources of wrongdoing.
is parodied by the Hipparchus — "all love the good" pushed to "everyone is greedy" (232c); the axiom run to eristic reductio by equivocating on "the good" (a dubium).
is complicated by the Second Alcibiades — a means/ends split: knowledge of means without knowledge of the best is harmful, and ignorance of particulars can prevent a crime (144c–146d) (a dubium).
contrasts with plato-statesman — the unity-of-virtue thesis is contested by the Statesman's claim that the parts of virtue (courage and moderation) are "in a sense extremely hostile" to one another (306b), so the statesman's weaving-art must reconcile them; see statesmanship.

Open Questions

Does Plato ever abandon intellectualism, or only supplement it? The Republic's tripartition restores irrational desire, but the philosopher-ruler's virtue is still knowledge of the Good — perhaps intellectualism survives at the top of the soul. The Laws IX answers supplement directly: it keeps the "no one errs willingly" slogan (860d) while adding anger and pleasure as independent sources of wrongdoing (863a–b).
Is the denial of akrasia Socrates' considered view or a dialectical result of the (possibly "the many's") hedonist premise in the Protagoras? The text leaves the endorsement undecidable.
Is the "unity of the virtues" identity (all are one knowledge) or biconditional dependence (one cannot have any without all)? The Protagoras arguments support different strengths.

Sources

plato-protagoras — virtue = knowledge; the unity of the virtues; "no one errs willingly"; the denial of akrasia (330c–333b, 349a–360e).
plato-gorgias — the ordered-soul psychology straining intellectualism (491d–494a, 503d–508a).
plato-meno — the teachability question and virtue-as-knowledge (87b–89a), ending in virtue as god-given without understanding.
plato-laches — courage-as-knowledge as a refuted definition (the Protagoras-mirror, 194d–199e).
plato-charmides — "knowledge of good and evil" as the aporetic terminus of the failed definition (174b).
plato-euthydemus — wisdom as the sole intrinsic good; the conditional-goods argument (281d–e).
plato-apology — "no one errs willingly" in the existential-forensic register (25c–26a, 29a–b).
plato-laws — intellectualism retained but supplemented by anger and pleasure (Book IX; 860d, 863a–b).
plato-hippias-minor — the craft-analogy of virtue run to a reductio: the two-way-power induction (373c–375c) and "the good man does injustice voluntarily" (376b), disavowed at 376b–c.
plato-hipparchus — the axiom "all love the good" run to the parody "everyone is greedy" (227a–c, 232c). A dubium.
plato-second-alcibiades — the thesis deployed (143d) yet complicated by a means/ends split (144c–146d). A dubium.