We present in this paper some characteristics of the interactions between the private and public sectors in health systems in four countries, with a particular emphasis on the case of France. The objective is simply to contribute to overcoming the most important impediment to a betterment of the health system in Québec and Canada, namely the irrational opposition of numerous political and special interest groups to a significant presence of private health care insurers and providers in our health system. We will document the significant presence of the private for profit sector in the French health care and hospital care system.