Stephen Dedalus struggles at Clongowes with linguistic enigmas and sexual enigmas, which are intimately connected in potent key-words such as “suck” and “smugging.” Through a close study of the unfolding of this sexual plot in the two structurally matching Clongowes sections, this essay shows that Joyce was a clear-sighted phenomenologist of sexuality, who shed light on the psychology of the “latency period.” The interplay of linguistic and sexual enigmas would remain fundamental to his art. While the material of A Portrait, chapter one, is ordinary schoolboy experience, its self-conscious literary handling, centred on a few charged signifiers, encases this experience in highly reflexive aesthetic recreation, in which luminous form goes hand in hand with psychological penetration.