Privatization, as a concept and as a political movement, is profoundly altering the shape of the public sector in the United States. Distinctions between the public and private sectors are being blurred as the organizations for accomplishing public purposes are more and more frequently a deliberate blend of public and private characteristics. Throughout this transformation in the public sector, the discipline and profession most directly affected by privatization, public administration, has been remarkably passive, both unwilling and unable to raise critical questions respecting the limits, if any, to privatization. This essay suggests that the origins of this passivity lie in the reality that public administration has largely forsaken its intellectual roots-roots which are embedded in public law, not in economics or the social sciences. Only by returning to public law, which emphasizes the distinctive character of the public and private sectors, will public administrators become influential players in the continuing debate over the future of the public sector.