A sense of the contingency of human, finite existence, reflections on its temporal embeddedness and on the possibility to act, to bring about other states of affairs in the world, i.e. what has sometimes been labeled the reflexivity of modernity, are not phenomena that appear only in the epoch of modernity. However, they become articulated in a distinctly new way, at the turn of the 18th century,
... [Show full abstract] one in which categories of the social and new notions of temporality and of agency become key components. Sociology came to depend on the existence of certain epistemic, institutional and existential conditions that allowed the new discourses of society to uphold epistemic claims to valid knowledge but also to reflexively engage in societal practices and their transformations. This article focuses on the ways in which this dilemma was articulated at three crucial historical junctures, namely the turn of the 18th century; the period of classical sociology in the late 19th and early 20th centuries, and finally; the present situation in the early 21st century with a global diffusion of professional sociological practices. This comparison in historical time is, for the last two periods of transformation, complemented also by a comparative analysis in space, by juxtaposing a Continental European experience with a North American one.