A popular theme in science fiction and cyberpunk is the replacement of the human body for the machine. The human identity has evolved beyond the physical self, as people switch limbs and organs all the time. The idea of life, then, becomes sentience, and separates from the body; the body is merely the physical manifestation of a person into the world, customizable as an accessory and almost a nuisance.
The idea of life separate from physicality is powerfully depicted in the movies Ghost in the Shell, Bladerunner, and the TV show Max Headroom. Major Kusanagi in Ghost in the Shell does not own any original parts; she is an artificial creation, a constructed person of great physical capability. Yet she is still considered human; she has a "ghost," a soul, a personality. Her existence is not bound to her artificial body, and as such neither is her identity; her ghost is easily transferable from one shell to another, as is done in the conclusion of the movie, when Bateau transfers her brain from her old, destroyed body to that of a small child. The idea is further expanded by Project 2501, or the Puppet Master, who claims to be a living being on account of its sentience, and, as such, deserves the rights of a human. A living thing no longer requires a specific body, only sentience and a place in society. Max Headroom, of the TV show of the same name, exists in television sets, but is not confined to one image or device. Wintermute and Neuromancer, the mastermind AIs of Gibson's Neuromancer, exist in cyberspace and only manifest themselves through the computers of the Sprawl, and the hypothetical technobrains theorized in Mitchell's Me++: The Cyborg Self need only any blank server space. The actual personis totally separate from the body. As the physical body is easily capable of being owned by somebody else, as a piece of property, it is no longer significant which body one inhabits, so long as it is as functional as desired.
An interesting development in artificial intelligence is the advancement into artificial sentience. A sign of sentience is emotion and personality; a life is valued if it can express an opinion as a function of its emotions. No matter how advanced we get, our minds and emotions are eternally linked to the ancient urges of our past. The artificial beings of Bladerunner certainly reflect the old human desire of longevity. The replicant Roy exhibits thirsts for vengeance, love, and pity, the AI Max Headroom expresses joy, amusement, and playfulness, the Puppet Master experiences the primal urge to pass on his data into a new being. Plenty of beings, complete with personalities (Wintermute, Count Zero, Colin, for example), exist in the cyberspace of Gibson's trilogy, and, despite their lack of functioning bodies, are treated like normal people with desires and demands. If humanlike sentience defines humanity, then many AI and artificial people similarly count as humans, especially when counting the separation of humanity and shell. A human is not a human body, but the collection of emotions, personality, and thoughts within the vessel. The human is the ghost, living within some shell.