The Logical Inconsistency of Transhumanism

Transhumanists such as Nick Bostrom and Ray Kurzweil argue that radical human enhancements will allow persons alive today to achieve a kind of technological immortality. The transhumanist movement has gained numerous followers who hope to live indefinitely as bio-enhanced 'posthumans' in a state of perpetual bliss. Transhumanism also has its opponents, however. Objections have been raised both to the possibility and to the desirability of the 'posthuman' future that transhumanists envision. This article argues that existing objections to transhumanism are vulnerable to one of two characteristic weaknesses. They depend either on debatable evaluative judgements or on doubtful speculation about the long-term future. Following this, I outline a new objection which, I claim, is not vulnerable to either weakness. According to this new objection, transhumanism presupposes two incompatible views of human nature.