"The Immortal" (original Spanish title: "El inmortal") is a short story by Argentine writer Jorge Luis Borges, first published in February 1947, Borges' conception of immortality assumes various manifestations throughout his writing and even in this clearly titled piece of work, it is not clear exactly who is meant to be the immortal. On one hand, Rufus is clearly searching for the city of the immortals and therefore the being that he finds there must in fact be the immortal. However, it could also be said that Rufus becomes the immortal once he embarks upon his journey. In this sense, Borges' immortality has to do with a Nietzsche-inspired humanist immortality which revolves around the super-abundant development of the person as an individual. This theme is also developed in "The Circular Ruins", "The Garden of Forking Paths", "The Sect of the Phoenix" and, in a sense, throughout all of Borges' writing.
Another theme present is the infinite, which can also be found in much of Borges' writing. The constant symbol of the infinite is the labyrinth, which represents a dynamic of personal choice within the infinite permutations of existence. The troglodyte who makes patterns in the sand and the hero (Rufus) who finds himself questing after and achieving immortality should be seen as synonymous, all-encompassing representations of the choosing individual within the infinite flux of the universe's permutations. As such, the infinite represents complete contradiction of the individual and also its validation.
"The Immortal" has been described as a fictional exploration of Nietzsche's theory of eternal recurrence, in which infinite time has wiped out the identity of individuals. The story can be compared to Homer's Odyssey, in the sense that it is a tribute to the universal, mythical proportion of Homer's work. The Immortal displays Borges' literary irony, fusing Swiftian satire, George Bernard Shaw's creative evolution in Back to Methusela, and the dream visions of Thomas De Quincey in a single work. Borges also comments on literary idealism in which the identities of component authors Homer, Shakespeare and Borges himself appear to merge into one another.