This paper proposes a way to capture marginality outside « categorization ». After discussing the links between marginality and social norms, the author puts forward, in a second step, the heuristic concept of "lesser life." This concept is rooted in the results of a multisited ethnography that took place in a homeless shelter and in a palliative care shelter for HIV/Aids patients. It aims to trace the sociological outline of marginality as a regime of constraints that minimize the potential to act by oneself.