Once the generality of the phenomenon has been established, one can, by showing its utility, confirm the results of the first method. We may, therefore, formulate the three following rules

A social fact is normal, in relation to a given social type at a given phase of its development, when it is present in the average society of that species at the corresponding phase of its evolution. | One can verify the results of the preceding method by showing that the generality of the phenomenon is bound up with the general conditions of collective life of the social type considered. | This verification is necessary when the fact in question occurs in a social species which has not yet reached the full course of its evolution.