In The Rules of Sociological Method (1895) Durkheim distinguishes between normal and pathological behaviour. The decisive characteristic of the normal form is that it is "generally distributed" (Durkheim 1895: 55). That is, it is to be found in the majority of individuals; where variations of behaviour are evident they occur within "narrow limits". Thus, in principle, a simple head count of a population will establish normal characteristics. To the "exceptional variations' in human behaviour, which he (1895: 55) avowed, "most often do not persist throughout the life of the individual," he proposed to affix the term "pathological" behaviour. He inferred that normal characteristics must perform necessary functions for society. For, he (1895: 58) reasoned, "it would be incomprehensible if the most widespread forms of organization would not at the same time be, at least in their aggregate, the most advantageous".