According to Durkheim, The source of social life is the similarity of consciousnesses and the division of labor. The former is best evident among ancient societies where a mechanical solidarity, evidenced by authoritarian law, prevails; the latter in advanced societies where populations evidence greater dynamic density, and juridical rules define the nature and relations of functions.In fighting individualism and basing the existence of societies on a consensus of parts, Durkheim refutes his positivistic stress which denies the importance of ends to a scientific study of society. In his conversation of social ends is a suppressed anti-mechanistic trend. The theory of uni linear development is established on deficient ethnographic data. It assumes the absence of division of labor among ancient societies and of any mechanical solidarity among modern societies. Repressive and restitutive law Durkheim seeks to use as indexes of mechanical and organic solidarity, but he does not establish with any accuracy the perfect relations which he assumes obtain between his types of solidarity and of law.