Self-Knowledge and Care of the Self

The Delphic command "know thyself" (gnōthi seauton) and its practical correlate "care for / cultivate oneself" (epimeleia heautou) form a single Socratic-Platonic imperative whose burden is to ask what the self is before it can be known or tended. The Alcibiades I gives the fullest development: caring for oneself is not caring for one's body, talents, or possessions (what merely belongs to one) but for the soul, because the self is the soul — the user/ruler of the body (130c). Knowing oneself is therefore knowing one's soul (130e), and the soul comes to know itself only reflectively, by looking at the wisdom-bearing region of another soul, as an eye sees itself in the pupil of another eye (the mirror analogy, 132c–133c). The genuine Charmides had already pressed (aporetically) the identification of sōphrosynē with self-knowledge, and the Phaedrus makes the Delphic question Socrates' first business (229e–230a). Caveat: the Alcibiades I's authorship is disputed (Cooper marks it †), so its clean doctrine is weak evidence about Plato's own development — it was prized in late antiquity precisely as the introductory text on self-knowledge (Olympiodorus, Proclus). Downstream, this is the locus classicus for Foucault's souci de soi.

Key Points

"Know thyself" redirected to the soul: the inscription is read epistemically and decoded — "the command that we should know ourselves means that we should know our souls" (130e). It is the dialogue's thesis-engine, not background piety.
Care of the self ≠ care of belongings: different skills tend a thing and what belongs to it (athletics the foot, shoemaking the shoe); self-cultivation is "a skill that won't make anything that belongs to us better, but will make us better" (128e) — so it requires first knowing what "we" are (129a).
The self is the soul (the user/used argument): "the user of a thing is always distinct from what is used" (129d); a man uses his whole body, so is distinct from it; "if he is something, he's nothing other than his soul" (130c). The soul is the body's ruler.
The mirror analogy (132c–133c): self-knowledge is dialogical — the soul knows itself by looking at "that region in which… wisdom occurs" in another soul, which "resembles the divine" (133c). The argument stops at 133c7; see the interpolation caveat below.
Sōphrosynē = self-knowledge: the Alcibiades flatly equates being self-controlled with knowing oneself (131b, 133c) — a tighter identification than the aporetic Charmides, where Critias proposes "knowledge of itself" but the inquiry stalls.
The dubia push the identity flat and route it through others (a dubium): the Rival Lovers derives self-knowledge from knowing good and bad others (the animal-analogy, 137e–138a), not from introspection, and asserts a three-way identity — self-knowledge = sōphrosynē = justice (138a–b) — that the genuine Charmides leaves aporetic; the Second Alcibiades keeps the Alcibiades I's fog/eye imagery but displaces the governing theme from self-knowledge to knowledge of the good as the precondition of right prayer (150e). See claims#plato-dubia-systematize-the-aporetic (live claim).
The cured failure is double ignorance: self-knowledge is what the man who "doesn't know but thinks he does" (118a) lacks — so the imperative targets the most harmful ignorance specifically.
The skipped question: Socrates concedes the proof is "not rigorous" and explicitly brackets "what 'itself' is, in itself" (auto to auto, 130c–d) — the metaphysical self is named and set aside. The result is a functional self (the ruling user), not a Form.

What the Concept Does

Makes self-knowledge the foundation of all worthwhile knowledge — one cannot know which of one's goods are good, manage a household or a city, without first knowing oneself (133c–135b); ambition without it is the unskilled helmsman steering to ruin.
Turns an oracle into a method — "know thyself" acquires a how (the mirror) and an object (the soul), converting Delphic piety into a procedure of soul-care.
Makes self-knowledge relational — one knows oneself not by introspection but by beholding the best part of another; self-knowledge passes through the other.

What It Rejects

Caring for one's "belongings" as caring for oneself — body, looks, wealth, allies are ta tinos, not the self (131a–c).
The body, or the body-soul composite, as the self — the ruled cannot be the ruler (130a–c).
Power and ambition without self-knowledge — "it's not walls or war-ships… that cities need… but virtue" (134b); until self-known and virtuous, one ought to be ruled, not rule (135b).

Stakes

If self-knowledge is care of the soul, then ethics is prior to politics and to every technē: one must become a certain kind of self before one's actions can be good. This is why the Alcibiades I held "pride of place in later antiquity as the ideal work with which to begin… Platonic philosophy" (Cooper), and why it is the cardinal ancient source for Foucault's souci de soi (the care of the self as an ethical practice) — though the wiki has no Foucault source ingested, so that genealogy is a pointer, not yet a sourced claim (confidence: speculative). Within the corpus, the Alcibiades' "self = soul as ruling user" is a third, minimal soul-model beside the Republic's partitioned soul and the Laws X cosmic self-mover — see claims#plato-self-is-soul-minimal-model (candidate).

Problem-Space

What is the self that must be known and cared for? The Alcibiades answers functionally — the self is the soul insofar as it rules — and deliberately skips the metaphysical question of what the soul is in itself (130c–d). The problem recurs wherever the corpus asks how the knower stands to what it knows: the Charmides' "knowledge of itself," the Republic's self-ruling soul, the Phaedrus' self-examination. The unresolved tension — a self defined by its function (ruling) yet whose nature is bracketed — is the seam between Socratic ethics and Platonic metaphysics of soul.

Connections

requires socratic-ignorance — self-knowledge is what double-ignorance (not knowing that one doesn't know, 118a) lacks; recognizing one's ignorance is its precondition.
is a reformulation of temperance-sophrosyne — the Alcibiades equates sōphrosynē with self-knowledge (131b, 133c), resolving by fiat what the Charmides left aporetic.
is asserted flatly by the Rival Lovers — a three-way identity (self-knowledge = sōphrosynē = justice, 138a–b) derived from knowing good/bad others, not introspection; a dubium that hardens what the Charmides holds open.
contrasts with tripartite-soul and priority-of-soul — the unitary user/ruler soul vs. the partitioned (Republic) and cosmic-self-mover (Laws X) models; the shared word psuchē hides three concepts. See claims#plato-self-is-soul-minimal-model (candidate).
contrasts with theory-of-forms — the rigorous "auto to auto" is the skipped question (130c–d), and the strongest divine-mirror lines are interpolated; reading the mirror passage as a Form-vision is doubly unsafe.
enacts eros — the true lover loves the soul (the self), not the body's bloom (131c–132a); Socrates is "the only lover" because he loves what Alcibiades is. Cross-ref the Symposium's drunken-Alcibiades encomium of the irreplaceable Socrates.

Open Questions

False friend / deferred claim: the editor flags an Aristotelian parallel — self-knowledge through a philosophical friend as a mirror (Magna Moralia 1213a20–24) — as a possible Plato[?]→Aristotle seed. But both texts' authenticity is disputed (the Alcibiades is †; the Magna Moralia is doubtfully Aristotle's), so the cross-tradition link is a false-friend caution, not a claim, until a securely-genuine attestation surfaces.
Interpolation hazard (citation-traceability): Hutchinson flags 133c8–17 (God-as-clearest-mirror) and 134d1–e7 ("pleases God / dark and godless") as later neo-Platonist additions, printed only in footnotes; the authentic mirror argument stops at 133c7 ("resembles the divine"). No page should cite the divine-mirror lines as Platonic.
Should this page eventually home Foucault's souci de soi and the late-antique commentary tradition (Olympiodorus, Proclus), or do those await a dedicated source ingest?

Sources

plato-alcibiades-1 — the full development: care-of-self vs. belongings (127e–129b); the user/used argument and self=soul (129b–130c); "know thyself" = "know your soul" (130e); the mirror analogy (132c–133c7); sōphrosynē as self-knowledge (131b, 133c); virtue-not-power (134b–135b). (Authorship disputed — † — so weak developmental evidence.)
plato-charmides — sōphrosynē proposed as "knowledge of itself"/self-knowledge and pressed to aporia (164d–169c); the genuine-dialogue anchor for the identification the Alcibiades makes flatly.
plato-phaedrus — the Delphic "know thyself" as Socrates' first business: "I look… into myself: am I a beast more complicated than Typhon, or… a gentler… creature?" (229e–230a).
plato-rival-lovers — self-knowledge derived from knowing good/bad others (137e–138a); the flat self-knowledge = sōphrosynē = justice identity (138a–b). A dubium.
plato-second-alcibiades — the Alcibiades I fog/eye imagery reused but the theme displaced to knowledge-of-the-good (150e). A dubium.