It comes from Hayles' How We Became Posthuman. The liberal subject is predicated on the notion that a) the subject must be self-contained and b) rational cognition is the point of consciousness. (This is why Descrates says that we can only know the world indirectly.) But in fact, neither is true; consciousness is a side-effect of embodiment, not its telos, and no subject is actually self-contained, especially not in the age of the cyborg.