There are many reasons why we might think that the human species might be in danger. We talk about global warming which produces major unusual natural disasters; increasingly destructive weapons; serious terrorist attacks with chemical weapons, etc. But we cannot ignore one of the threats hanging over the human species, which is transhumanism or posthumanism. It is from the point of view of this last subject, on which much has already been written, that we will try to focus our analysis, paying particular attention to the question relating to gene editing (CRISPR/Cas 9).