Obsession
Nikola Tesla urges Angier to give up on his transport machine because he recognizes an obsession when he sees it and know from personal experience how badly they can break. Angier’s response is exactly what an obsessed person would think: “If you understand an obsession, then you know you won't change my mind.” That is the whole point of obsessive behavior: it is irrational and immune to appeals of logic. Angier is not alone. Tesla has already admitted his obsessive tendencies, but it is Borden who perhaps proves willing to take his obsession well past the point of at which sane recognition of irrational self-interest has elapsed.
Identity
If the movie itself can said to have an obsession, it would be with the nature of identity. Throughout the narrative, questions about the nature of identity are consistently raised. Sarah Border is never completely sure whether her husband loves her from day to day. Robert Angier is at various points known or referred to as the Great Danton and Lord Caldlow. An assortment of characters appears in disguises or pretend to be someone else. At least one character engages the service of a physical lookalike to perform an illusion on stage. And, of course, the two great final plot twists of the movie are both incredible revelations of how identity and the self can be separated, unified and even copied to suit a purpose as necessary.
Rivalry
The essential element driving the events of the narrative is the rivalry between two competing magicians. The increasing intensity of the rivalry is the engine which drives the obsessive behaviors. The obsessive behaviors push both characters to test the limits of the nature of identity and push the envelope of the meaning of the self. What lifts the exploration of this theme to the next level, however, is the way it is pursued in its totality. The introduction of Nikola Tesla as the genius Angier hires to build his secret transport machine introduces the real-life historical rivalry that existed between Tesla and Thomas Edison. Angier is also briefly drawn into a rivalry with the lookalike he uses before going to Tesla. Borden’s wife Sarah believes that magic is her rival for her husband’s love, allowed to remain cruelly unaware of the real extent of the perverse nature of her rival. Ultimately, when all the secrets are finally divulged, another rivalry is revealed: that existing between mere magical illusion and actual technological magic as it is made clear that one character used cheap stage gimmickry and the other a revolutionary advance in scientific possibilities to accomplish the same trick. Rivalry is forwarded as an agency capable of producing both incredibly positive and incredibly negative consequences, possessing no inherent morality in itself.
