When and how did philosophy undergo professionalization? "Professionalization tends to result in establishing acceptable qualifications, one or more profession

When and how did philosophy undergo professionalization? "Professionalization tends to result in establishing acceptable qualifications, one or more professional associations to recommend best practice and to oversee the conduct of members of the profession, and some degree of demarcation of the qualified from unqualified amateurs (that is, professional certification). It is also likely to create "occupational closure", closing the profession to entry from outsiders, amateurs and the unqualified."