The meanings of words shift over time. In the 13th century the word 'nice' meant foolish, or stupid. Today, the word 'professional' has been shifting to refer to pretty much anything done for money. But this erosion of meaning muddies the critical distinction embodied in the term.
Professional specifically describes a highly qualified individual conscientiously delivering knowledgeable and skilled service to others who are in a position of vulnerability related to that service. It represents an agency relationship, where one party (the client) trusts someone they have empowered (the professional) to provide a standard of care with uncompromised integrity.
The phrase 'worlds oldest profession' points not to the prostitute, but to the shaman. Just because something is done with skill or on a purely mercenary basis does not elevate it to professional service. In the true context of the word, then, labels like 'professional wrestling' or 'professional football' are oxy moronic. Dare I say, in reality there is no such thing as a professional athlete. Mercenary, maybe. Tiger's fortune on the links is and always has been pretty much about Tiger. Celebrity; yes. Entertainer; yes. Extraordinary skill and talent; absolutely. Professional; not really.
Probably the most explicit description I have heard distinguishing the word 'professional' came to me from a doctor who shared the gruesome history of forceps, invented by a midwife in 16th century England and kept as a closely held family trade secret for over 100 years. The device consists of two interlocking levers separately inserted into the birth canal. Tragically, when the family trade secret was finally stolen, the technology was only partially revealed; one lever was taken, but its mirrored companion was unknowingly left behind, so suddenly midwives all across London were attempting to use crude replicates of half of the device... with horrific results. Apart from the initial innovation, everything about this story is revolting. The underlying issue was care givers putting their personal interests first. They provided a service for which they gained considerable fame and fortune, but there was nothing professional about it. The doctor I was speaking with was making the point that true professionals invariably share their knowledge with one another to continually elevate their profession, valuing that ideal over seeking to gain any sort of competitive advantage.
Professionals are licensed by states in the U.S., because our constitution empowers individual states with police powers exclusively to protect public health, safety, and welfare. Although I hold a national certificate that expedites my acquisition of professional registration in states where I am not presently licensed, when I cross the border from, say, Montana into North Dakota, I simply cease to be an architect, and to claim or even imply otherwise would be to break the law. This is the case in every state in the nation, and the law is severe and unforgiving. All for good reason. So, buyer beware; if you are talking to someone who refers to themselves as a Designer, or Architectural Designer, or Associate AIA, or any of the rest, you are dealing with someone who lacks the rigorous training and credentials of a professional licensed architect.
Years ago, interviewing potential candidates for openings in our firm, I met a Russian immigrant who claimed to be an architect. The problem for both of us was that in the U.S.S.R., there was no architectural profession, as such. Nor was there any professional licensure path. If you were an 'architect' you were really just an unlicensed engineer that designed factories, canneries, and apartment blocks with about the same levels of engagement of the human spirit across the board. You were assigned your career by the state, who was also your only client. In reality, for a variety of reasons, there was no architecture to speak of. Construction, sure. Lots of construction, but no architecture, and no architectural profession. When the wall came down in Germany, the cumulative contrast was visually glaring; vitality, energy, and creativity on one side, and on the other, blight, depression, and oppression.
This experience deepened my appreciation for the strength of my chosen profession here at home. I believe the architectural profession in the U.S. is in many ways stronger and more relevant than ever, that it has a vital role to play in our future, and that many of the best architects in architectural history walk among us. I believe that as design professionals, we absolutely must have the best interests of our communities and of our clients taken to heart, and I see inspiring evidence of this happening all around me. I humbly feel great pride in, and hope for, my ever-demanding and ever-giving profession.