Plutarch De curiositate 12

[12] In the second place, then, let us accustom ourselves not to look inside when we pass another’s door, nor with our curious gaze to clutch, as it were by main force, at what is happening within, but let us ever keep ready for use the saying of Xenocrates, that it makes no difference whether it is the feet or the eyes that we set within another’s house; for what the eyes behold is neither just nor honourable, and not even pleasant. since the greater part of what we see inside is of this sort-kitchen utensils lying about and servant-girls sitting in idleness, and nothing important or pleasurable. And this practice of throwing sidelong and furtive glances, distorting the soul as it does, is shameful, and the habit it implants is depraved. For instance, when Diogenes ² saw the Olympic victor Dioxippus making his triumphal entry in his chariot and unable to tear his eyes away from a beautiful woman who was among the spectators of the procession, but continually turning around and throwing side-glances in her direction, Do you see, said the Cynic, how a slip of a girl gets a strangle-hold on our athlete? And you may observe how every kind of spectacle alike gets a strangle-hold on busybodies and twists their necks round when they once acquire a habit and practice of scattering their glances in all directions. But, as I think, the faculty of vision should not be spinning about outside of us, ³ like an ill-trained servant girl, but when it is sent on an errand by the soul it should quickly reach its destination and deliver its message, then return again in good order within the governance of the reason and heed its command. But as it is, the words of Sophocles ⁴ come true: that is, the senses which have not received what we called above right instruction and training run away, dragging the intellect with them, and often plunge it into deep disaster. Consequently, though that story about Democritus ⁵ is false, that he deliberately destroyed his sight by fixing his eyes on a red-hot mirror and allowing its heat to be reflected on his sight, in order that his eyes might not repeatedly summon his intellect outside and disturb it, but might allow his mind to remain inside at home and occupy itself with pure thinking, blocking up as it were windows which open on the street; yet nothing is more true than this, that those who make most use of the intellect make fewest calls upon the senses. ⁶ We observe, for instance, that men have built their sanctuaries of the Muses ⁷ far from cities and that they have called night kindly ⁸ from a belief that its quiet and absence of distraction is greatly conducive to the investigation and solution of the problems in hand.