In the Post-modern ages, the human being is doubly put into question : naturalisation of humanity (strong naturalism) is challenged by the hypothesis that man transcends the natural order; a self-based liberty is challenged by the ethics of responsibility, according which man is requested to be responsible for the Nature he is able to destroy. How can we deal with such a undetermined human nature and on the other hand, with a specific responsibility of mankind over Nature? This paper examines several theories of the environment reconsidered as a place of humanization that is to be shared. This allows an intercultural ethics of the world as vital for all, beyond any ethnocentric normativity. How can we justify that the world is not available to appropriation? Nevertheless, how can we have a use of the world combining humanization, socialization and personal development? How can we ‘co-operate’ the world through our vital links so that we become more human the ones by the others?