[Scientific ethics of the origin of humans].

The analysis of the early human life from the view point of a scientific ethics is presented. Life is a historical materioenergetic process of specific organization. This phylo-ontogenetic process is a continuous process without interruption. Biology has demonstrated that human eggs or embryos are full human individuals, even though not all human conception is a human being. The contradictions involved in taking ethical decisions after knowing the percentage of conceptions obtained by in vitro or in fallopian tube fertilization that reach the birth are shown. The advantages of scientific ethics in the analysis of the origin of the different positions are indicated. These advantages come from the dissection of the different cognitive, affective-emotional and value attribution frames involved in the alternative decisions.