Orality is a major component of the organization of the libido during the first, pregenital phase of its development; it is thus an essential aspect of psychosexuality.

Freud gave his first overall description of the phases of the libido in his Three Essays on the Theory of Sexuality (1905d). Sucking, initially autoerotic, is the earliest expression of the instincts. It is anaclitically supported by a function necessary to the preservation of life, the absorption of nourishment. Pleasure is therefore linked to an erotogenic zone, the mouth, and more specifically to the mucous membranes of the lips and mouth. This pleasure will later be found again in kissing, in the pleasure of eating, drinking, or smoking, and so forth, and it can become the basis for perverse practices. This excitability may persist throughout life, linked—to some degree—to genitality. Due to the very fact of this link, oral pleasure may be...