<<And you don't have professional coal miners because you don't have amateur coal miners to distinguish them from. [etc.]>>
While I agree with your definition of 'professional' (and find your retort funny) I do not agree that that definition is exclusive. Below is a partial bibliography, available at
http://palinurus.english.ucsb.edu/BIBLIO-BUSINESS-new-class.html#general, which suggests there may be a broader scope of definition:
* Burton J. Bledstein, The Culture of Professionalism: The Middle Class and the Development of Higher Education in America (New York: Norton, 1976)
* Barbara and John Ehrenreich, "The Professional-Managerial Class," Radical America, Part 1, 11 (March-April 1977): 7-31; Part 2, 11 (May-June 1977): 7-22
* Amital Etzioni, ed., The Semi-Professions and Their Organization: Teachers, Nurses, Social Workers (New York: Free Press, 1969)
* Magali S. Larson, The Rise of Professionalism: A Sociological Analysis (Berkeley, CA: Univ. of California Press, 1977)
* M. Oppenheimer, "The Proletarianization of the Professional," Sociological Review Monography no. 20 (1973): 213-27
* W.J. Reader, Professional Men: The Rise of the Professional Classes in Nineteenth-Century England (New York: Basic, 1966)
