The double hermeneutic is the theory, expounded by sociologist Anthony Giddens, that everyday "lay" concepts and those from the social sciences have a two-way relationship.[1] A common example is the idea of social class, a social-scientific category that has entered into wide use in society. Since the 1970s, held to be a distinguishing feature of the social sciences,[2] the double hermeneutic has become a criterion for demarcating the human/social from the natural sciences.[3][4]