I distinguish the ethics of transhumanism from a related metaphysical position which I refer to as “speculative posthumanism.” Speculative posthumanism holds that posthumans might be radically non-human and thus unintelligible in human terms. I claim that this transcendence can be viewed as analogous to that of the thing-in-itself in Kantian and post-Kantian European philosophy. This schema implies an impasse for transhumanism because, while the radically non-human or posthuman would elude evaluation according to transhumanist principles such as personal autonomy or liberal freedom, it is morally unacceptable for transhumanists to discount the possible outcomes of their favoured policies. I then consider whether the insights of critical posthumanists, who employ a cyborg perspective on human-technology couplings, can dissolve this impasse by “deconstructing” the opposition between the human and its prospective posthuman successors. By exhibiting its logical basis in the postructuralist philosophies of Derrida and Deleuze, I show that the cyborg perspective is consistent with both cyborg humanism and a modified speculative posthumanism. This modified account treats the alterity of the posthuman as a historically emergent feature of human and posthuman multiplicities that must be understood through their technical or imaginative synthesis, not in relation to a transcendental conception of the human
