One aspect of the consensus perspective Emile Durkheim developed is that of functional analysis as a form of sociological explanation. In his Rules, he suggested that in explaining social facts investigators should
In the search for causes, the sociologists should look for antecedent social facts – those social facts which precede and seem to produce the particular social facts under investigation. In the search for functions, he should look to the general needs of the social organism. The phenomena to be studied are social facts that is some emergent phenomena which only arise from man associating with man. These phenomena cannot be reduced to psychological or biological factors. Although Durkheim assumed that men may have the same basic human nature and psychological characteristics, he was not interested in studying these. What interested him was the fact that despite these probable similarities, men developed different social relationships and social arrangements in different societies. To explain any of these social facts, we look for antecedent social facts on the one hand and on the other, for the functions the facts fulfil in the maintenance of the social system in which they are found. In looking at the antecedent social facts, we look at the internal constitution of a social group – to the qualities and conditions of social life which are characteristic of any particular social group. It is the social organization – the nature of social ties and social solidarity of any group that is the fundamental reality beyond which the sociologist need not investigate. Once he gets into psychological or biological factors, he is no longer doing sociology.