Plotinus's Enneads
On Beauty
“Withdraw into yourself and look. And if you do not find yourself beautiful yet, act as does the creator of a statue that is to be made beautiful: he cuts away here, he smooths there, he makes this line lighter, this other purer, until a lovely face has grown upon his work. So do you also: cut away all that is excessive, straighten all that is crooked, bring light to all that is overcast, labour to make all one glow of beauty and never cease chiselling your statue, until there shine out on you from it godlike splendour of virtue, until you shall see the perfect goodness surely established in the stainless shrine…” - Plotinus, Enneads, 1.6.9
Ennead I.6 ("On Beauty"), where Plotinus explores how true beauty resides in the soul's alignment with the intelligible realm through virtue, rather than in mere physical symmetry. The "splendour as of Light" resting upon the virtues signifies a divine illumination akin to the Form of the Good in Plato.
(Ennead I, Tractate 6, sections 5–7 in the standard division), in the classic English translation by Stephen MacKenna (with minor revisions in some editions).
The passage discusses the beauty of the soul through virtue and contrasts it with the ugliness arising from vice and attachment to the material.
Soul to loveliness: what is this grace, this splendour as of Light, resting upon all the virtues? Let us take the contrary, the ugliness of the Soul, and set that against its beauty: to understand, at once, what this ugliness is and how it comes to appear in the Soul will certainly open our way before us. Let us then suppose an ugly Soul, dissolute, unrighteous: teeming with all the lusts; torn by internal discord; beset by the fears of its cowardice and the envies of its pettiness; thinking, in the little thought it has, only of the perishable and the base; perverse in all its impulses; the friend of unclean pleasures; living the life of abandonment to bodily sensation and delighting in its deformity. What must we think but that all this shame is something that has gathered about the Soul, some foreign bane outraging it, soiling it, so that, encumbered with all manner of turpitude, it has no longer a clean activity or a clean sensation, but commands only a life smouldering dully under the crust of evil; that, sunk in manifold death, it no longer sees what a Soul should see, may no longer rest in its own being, dragged ever as it is towards the outer, the lower, the dark? ….
An unclean thing, I dare to say; flickering hither and thither at the call of objects of sense, deeply infected with the taint of body, occupied always in Matter, and absorbing Matter into itself; in its commerce with the Ignoble it has trafficked away for an alien nature its own essential Idea. If a man has been immersed in filth or daubed with mud, his native comeliness disappears and all that is seen is the foul stuff besmearing him: his ugly condition is due to alien matter that has encrusted him, and if he is to win back his grace it must be his business to scour and purify himself and make himself what he was. So, we may justly say, a Soul becomes ugly – by something foisted upon it, by sinking itself into the alien, by a fall, a descent into body, into Matter. The dishonour of the Soul is in its ceasing to be clean and apart. Gold is degraded when it is mixed with earthy particles; if these be worked out, the gold is left and is beautiful, isolated from all that is foreign, gold with gold alone. And so the Soul; let it be but cleared of the desires that come by its too intimate converse with the body, emancipated from all the passions, purged of all that embodiment has thrust upon it, withdrawn, a solitary, to itself again – in that moment the ugliness that came only from the alien is stripped away.
Plato's Symposium 210b–c, where Diotima describes the ascent from physical beauty to the contemplation of absolute Beauty