More than any other human reality, Ulysses is about love—sexual love. June 16, 1904 was the date on which Joyce first went out walking, on Sandymount Strand, with Nora Barnacle. (She pulled him off inside his pants, and he was smitten.) Fictionally, it is the day on which the sexual dysfunction in the Blooms’ marriage reaches a climax, as Molly begins an affair with Blazes Boylan. In Telemachus Joyce implicitly connects the crisis in the Blooms' marriage with his young persona's progress toward maturity: "Pain, that was not yet the pain of love, fretted his heart."
In Proteus Stephen, walking alone on Sandymount Strand, imagines an encounter like the one Joyce found with Nora: “Touch me. Soft eyes. Soft soft soft hand. I am lonely here. O, touch me soon, now." He goes on to think, "What is that word known to all men? I am quiet here alone. Sad too. Touch, touch me.” Gabler’s 1984 edition explicitly answers the question about the “word known to all men,” by adding to Scylla and Charybdis several sentences of internal monologue left out of previous editions: “Do you know what you are talking about? Love, yes. Word known to all men. Amor vero aliquid alicui bonum vult unde et ea quae concupiscimus ...” Whether or not this “correct answer” to the question belongs in the novel, its mere existence in Joyce’s handwriting encourages a reader to suppose that Stephen wishes to understand the emotion of love better than he presently does.
Gifford traces Stephen's Latin sentence to a passage of Aquinas’ Summa Contra Gentiles, several unconnected phrases of which he recalls and patches together in memory. The sense of the rather contorted Latin is that true love (amor vero) makes one will another person’s good (aliquid alicui bonum vult), whereas those things which we merely desire or covet (ea quae concupiscimus) we desire for our own good, not the good of the other. Aquinas is making an essentially Augustinian distinction between real love (caritas) and mere desire (cupiditas).
In a preface to the paperback release of Gabler’s edition, Richard Ellmann commented on the inclusion of these sentences as exemplifying the novel’s central message of love. Ellmann's preface observes that the message is announced again in Cyclops, when Bloom argues that force and hatred are not the essence of life: “everybody knows that it’s the very opposite of that that is really life . . . Love.” The Citizen, his antagonist in the pub, immediately mocks the Jew for promoting a Christian message of “Universal love,” and the narrative itself chimes in by mockingly chanting, “Love loves to love love . . . You love a certain person. And this person loves that other person because everybody loves somebody but God loves everybody.”
This may be sheer “twaddle,” Ellmann observes, but it aligns Bloom’s world-view more or less with that of Aquinas, for whom love is a universal cosmic principle deriving from God. The annihilating mockery “protects seriousness by immediately going away from intensity.” But while diverted from “didacticism or sentimentality, we perceive that the word known to the whole book is love in its various forms, sexual, parental, filial, brotherly, and by extension social. It is so glossed by Stephen, Bloom, and Molly.” Ellmann’s un-Christian conclusion: “Affection between human beings, however transitory, however qualified, is the closest we can come to paradise.” The human love that Stephen is struggling to discover, and that Bloom and Molly are simply struggling with, represents a kind of universal principle in the novel, comparable to (but radically different from) the divine love expounded by Christian writers.
In A Portrait, Stephen’s one significant literary accomplishment was a love poem addressed to the young woman identified only as E. C. It is radiantly beautiful, but filled with Catholic notions of sin. On the last page of the novel Stephen encounters E. C. after a long absence, and she "Asked me, was I writing poems? About whom? I asked her. This confused her more and I felt sorry and mean. Turned off that valve at once and opened the spiritual-heroic refrigerating apparatus, invented and patented in all countries by Dante Alighieri. Talked rapidly of myself and my plans."