The main aim of this article is to offer a sociological concept of crisis that, defined as the expected yet non-lineal outcome of the internal dynamics of modern societies, builds on the synergies between critical theory and systems theory. It contends that, notwithstanding important differences, both traditions concur in addressing crises as a form of self-reproduction of social systems as much as a form of engagement with the complexities and effects of such processes of reproduction. In order to make our (...) comparison exhaustive, this article explores critical and systems theories’ notions of crisis at three levels: (1) their conceptual delimitation of crises; (2) their methodological proposals to empirically observe crises; and (3) their normative attempts to contribute to their resolution. As crises remain a distinctive structural feature of the social world and a rich source of knowledge about it, reflexivity must be seen as a crucial form of engagement with the negative expressions of social life itself. (shrink)