Adolphe Quetelet’s work was almost exclusively studied by the historians of statistics. The study presents here the innovations of Quetelet regarding empirical analysis of society, then those of Durkheim, in Le Suicide, in the light of the previous ones; and specifies what can be easily intepreted as loans. To this end, the study distinguishes two steps of Quetelet’s work: the first one is the construction of the ‘penchant’ of the average man, the second is his probability theory. The former, the least known, is the one by which the work of Durkheim ans his collective psychology are most inspired, in the point to reproduce some initial analogies and ambiguities.