My first premise is that professionalism is a self-conscious endeavor by members of an occupation to distinguish themselves from competitors by claiming special competence and initiating a set of binding norms that enables them to close ranks, gain official recognition, and consolidate their power within a market. What distinguishes a profession from a non-professional occupation is that it is self-defining and self-regulating. As a profession, it is inner-directed rather than other-directed or tradition-directed.
Samson, Steven Alan, "Professionalism: A Political Strategy for Occupational Control" (1980). Faculty Publications and Presentations. 32.