“Posthumanity” has established itself as a label for a form of human existence radically transformed by the most advanced medical techniques and by the use of neuro, bio and nano and other technologies for human enhancement. In itself, “posthumanity” is a value-neutral term that neither implies nor excludes any specific attitude one might assume towards the prospect of a “posthuman” future. Nonetheless, the concept is bound up with a fairly fundamental controversy about values. It has done much to lay open the split in attitudes in our culture between those who welcome “posthumanity” as a positive vision appropriate to guide our strategies in scientific research, technology and medicine, and those who think that the dangers inherent in this vision so much outweigh its promise that we should resist the temptation to “improve” the human race by means of science and technology. “Transhumanists” like Nick Bostrom (cf. 2003, 2005) define themselves by taking a decidedly positive view of the prospect of a “posthuman” future, whereas “bioconservatives” like Leon Kass (cf. 1997) are more sceptical of this prospect and tend to warn us not to invest too much, mentally and economically, in what is seen as a threat rather than as a paradise. Semantically, the terms “transhumanism” and “posthumanity” are closely connected. “Transhumanism” can be defined as a movement that wants us to get on the way to “posthumanity” by going beyond humanity in its present form. Transhumanists want us to enter upon a process that will ultimately lead to “posthumanity” by attempting, now and in the near future, to transcend certain limits inherent in the human condition as we know it.