Abstract
We know today that classical eugenics, of an essentially negative nature, was not only an aggressive and brutal practice but, like its positive counterpart, inefficient as well. In fact, numerous biological, sociological, and psychological events beyond our control arise to prevent the realisation of any eugenic plan. Thus, like all human beings, individuals whose procreation is encouraged by positive eugenics suffer unexpected mutations that are transmitted to their offspring by their gametes. Gene distribution among the gametes at meiosis is the result of an uncontrollable, natural lottery. As an effect of this lottery, positive eugenics could allow the birth of defective babies whereas negative eugenics precludes the birth of normal babies.