Sociologists have debated extensively about the attributes and natural history of professions, roughly dividing along two lines. The taxonomic and functionalist views assume that professions rest on broad knowledge based on extensive, specialized training, usually, in the modern era, in a university setting. Because such knowledge is arcane and scarce and outsiders lack the expertise to judge it, society allows the profession to regulate itself and to monopolize services. In turn, the profession follows a service ethic rather than the profit motive. It pledges to help all in a disinterested fashion and to maintain high ethical standards among its members. Since the 1960s, the critical or power school has treated professionalism as ideology and manipulation, arguing that the extent of training and the specialized character of professional knowledge are deliberately exaggerated and mystified and that the service ethic merely disguises unjustified monopoly rewards (Saks, 1983; Wilensky, 1964; Greenwood, 1957; Friedson, 1984; Roth, 1974; Ritzer and Walczak, 1986: 59–94).