In this article, we tried to decrypt the nature, the structure and the ways of actions of an active minority within developped countries. Individuals who belong to the transhumanist movement reflect to some extent the conflictual situation which is the own case of our Mankind in this beginning of 3rd millenary which has to cope with the growing importance of Sciences, Techniques and Technology in our daily lives. Discussing about the future of Mankind, Transhumanists interrogate burning core questions which put forward a new ideal posthuman identity where technique, helping human beings, restores their social and cosmological legitimacy.