Metafiction breaks with conventional narrative form by upending traditional reader expectations. "The Shape of the Sword" is a metafictional in its use of doubling: the person who tells the story to the narrator turns out to identify as a main character in his story, a revolutionary he betrayed, and himself, the traitor John Vincent Moon. At first, he takes on the viewpoint of the man he betrayed, seeing himself, Moon, as he imagines he is seen by this other man. He then reveals that he is the traitor. The crescent-shaped moon scar that dramatically cuts his face into two parts, he reveals, was made by himself, symbolizing his betrayal of his other "self":

I seized a scimitar, and with that steel crescent left a flourish on his face forever—a half-moon of blood.

Or perhaps, the "I" that did this was the revolutionary he betrayed, whom he perceives as another facet of himself.

The story profoundly calls personal identity into question, and here, intertextuality comes into play. The story looks to other texts to raise questions of identity. The storyteller states,

Whatsoever one man does, it is as though all men did it. That is why it is not unfair that a single act of disobedience in a garden should contaminate all humanity; that is why it is not unfair that a single Jew's crucifixion should be enough to save it. Schopenhauer may have been right—I am other men, any man is all men, Shakespeare is somehow the wretched John Vincent Moon.

This is a radically different way at looking at human identity. Instead of the sharp individuality that Western society often insists on, in this telling, all humans are intertwined as one, and what one does, everyone does. By referencing such authoritative figures as Jesus, Schopenhauer, and Shakespeare, Moon lends credence to the idea that he can be both victim and traitor.

By evoking Schopenhauer—and also by the fact that the owner of the house the storyteller is living in is a man living in Bengal, India—the storyteller unites Eastern and Western thought, since Schopenhauer's ideas of individuality were influenced by Hinduism.

It is worth noting, too, that the narrator calls himself Borges. Normally, the narrator of a story is kept distinct from the author, but in this case, Borges conflates himself with this figure, adding another layer of confusion to our ideas of identity. By making it unclear who is telling the story or who is who according to our conventionalized notions of character, Borges keeps us disoriented about how to position ourselves vis-à-vis the text. This makes it harder to judge right and wrong. We are, instead, in a state of uncertainty that perhaps more accurately reflects reality than the traditional assured narrative voice.