Despite its present-day success story in the field of management, corporate social responsibility (CSR) is not a new concept, but one that emerged in the 1950s. One may therefore wonder about such a resurgence for a concept whose interpretations are numerous and sometimes quite opposed to one another. Our hypothesis is that CSR, understood on a very topical functional level, results from a deficiency of substantive law. This gap could also explain the evolution of the historical and conceptual approach of CSR, perceived on a second level: the need to seek a foundation in ethics first, and then in political philosophy. However, such a search for foundations does not necessarily succeed. Nevertheless, far from limiting ourselves to a critical standpoint, we try to propose here a clarification of CSR and all the levels involved, in particular the ethical standpoint, which could be more deeply analyzed.