Contemplating the likelihood that he will be evicted from the tower, or shun it in response to Mulligan's claim of ownership, Stephen thinks, "Now I eat his salt bread." He is recalling a powerful literary evocation of exile and homelessness in The Divine Comedy, when Dante learns from his ancestor Cacciaguida that he will be exiled from Florence.
The souls in Dante's afterlife can see the future. In Paradiso Cacciaguida tells Dante that he will be banished from the great city-state of his birth and forced into an itinerant existence, wandering about the Italian peninsula in search of shelter, protection, and patronage. Florentines put little salt in their breads, so even his daily bread will discomfit him:
You will leave behind every delightful thing
You most love; and this is the arrow
That the bow of exile first shoots.
You will discover how full of salt
Is the bread of another, and how hard the way
Going down and up another’s stairs.(17.55-60, my trans.)
Stephen, who has been going up and (just now) down the stairs of Mulligan’s tower, contemplates handing over the key and becoming utterly dishoused: “Give him the key too. All.”
At about this time in Joyce's own life (1900-1904), he was beginning to think of himself as a writer-in-exile. Ellmann notes that Henrik Ibsen's warm acknowledgement of the essay "Ibsen's New Drama" that Joyce published in the Fortnightly Review in 1900 encouraged the young man to think of himself as standing "aloof" from his peers (74). "Before Ibsen's letter Joyce was an Irishman," Ellmann observes; "after it he was a European" (75). He read all the late nineteenth century European literature he could get his hands on, and much else besides; "He continued his study of Dante, so that it was easy for Oliver Gogarty to dub him a little later the Dante of Dublin" (75).
In December 1902 Joyce departed from Kingstown pier for his first exile on the Continent. In October 1904 he left again, with Nora, this time for good. Of the first departure Ellmann remarks, "He was not yet using the word 'exile,' but there are hints of it in his letter to Lady Gregory. Joyce needed exile as a reproach to others and a justification of himself. His feeling of ostracism from Dublin lacked, as he was well aware, the moral decisiveness of his hero Dante's exile from Florence, in that he kept the keys to the gate. He was neither bidden to leave nor forbidden to return, and after this first departure he was in fact to go back five times. But, like other revolutionaries, he fattened on opposition and grew thin and pale when treated with indulgence" (109). In A Portrait of the Artist Stephen declares that the tenets of his artistic caling will be "silence, exile, and cunning."