Aidōs (’shamefastness’) is a sort of voltage of decorum discharged between two people approaching one another for the crisis of human contact, an instinctive and mutual sensitivity to the boundary between them. It is the shame suitably felt by a suppliant at the hearth (e..g, Od. 17.578), a guest before his host (e.g., Od. 8.544), youth making way for old age (e.g., Soph. OC 247), as well as the shared shyness that radiates between lover and beloved (e.g., Pind. Pyth. 9.9–13). The proverbial residence of aidōs upon sensitive eyelids is a way of saying that aidōs exploits the power of the glance by withholding it, and also that one must watch one’s feet to avoid the misstep called hybris. In erotic contexts aidōs can demarcate like a third presence, as in a fragment of Sappho that records the overture of a man to a woman:
θέλω τί τ᾽ εἲπην, ἁλλά με κωλύει αἲδως….
I want to say something to you, but aidos prevents me….
Anne Carson, Eros the Bittersweet