Human beings desire to become better. Education and development of tools have helped them to reach this goal for many a time. But what is the ultimate goal? A classical answer is: to be happy. Till now, the result has not been very convincing, but transhumanism has recently taken responsibility for this project, giving us hope to be happy and to live longer. However, will we become more human or posthuman? Transhumanists hesitate between both, but think after all that no limit should be laid down in advance. Consequently, nothing is sacred in human nature and changing it raises no moral concern. Saying this, transhumanism puts itself inside an old tradition, claiming that the value of a human being does not consist in his humanity but in the fact that he is a person, that is a being endowed with reason - reason being the source of all progresses. Consequently, there is a continuity between humanism and transhumanism, and we have good reasons to hope for a bright future. However, the life in our contemporary societies, where everything goes faster and stronger, does not seem to go in this direction. Will transhumanism be able to correct our mistakes? To succeed, it should also aim at human moral enhancement, a hope for some, but a nightmare for others.