This touches on the professions' concerns with education and training. Part of all this is a concern to establish and maintain a distinctiveness, a separateness, from other professions. This is the defining and occupying of professional 'niches'. The intention and effect of this is the establishment and maintenance not only of levels of competence but also of a special responsibility - often for activity that once was undertaken more widely in society. Such 'creeping professionalisation' is sometimes regarded as a continuation of the division of labour in complex cultures.
Professionals enable clients to do things which they are unable to do by themselves.
Nowadays, it is frequently unclear who exactly the 'client' is. The existence of distinctively trained professionals raises some interesting questions about several important matters. Dear Jim, I accidentally ran into an old friend of my father's the other day. He told me he had bought land in Kent with the idea of building himself a house, and was looking for an architect. If you will confirm that you sent the parcel, I will return it to you.