The legal profession as we know it today was born between the 12th and 13th centuries in Europe, and most especially at the University of Bologna.  The new lawyers practiced in church courts — indeed, as James Brundage notes in his magnificent study, The Medieval Origins of the Legal Profession: Canonists, Civilians, and Courts (Chicago Press 2008):

[P]rofessional lawyers first emerged in the courts of the medieval church.  Practitioners in civil courts that employed the procedural system of the ius commune [the common, learned law] quickly followed suit and adopted procedures that resembled those already introduced in the ecclesiastical courts.  Development of a professional identity among the canonists thus seems to have supplied a model that other professional groups, such as English common lawyers and university-trained physicians, adapted to their own needs and purposes.  (3)

The term “profession,” Brundage argues, had religious roots “connected with making a solemn promise or undertaking” — as in the phrase, “a profession of faith” — and “[m]edieval lawyers were undoubtedly aware of these religious connotations of ‘profession’ when they used the term professio advocatorum, familiar to them from Roman legal sources, to describe themselves and their colleagues.” 

It is not often that the connections between religion and the idea of law as a profession — and therefore of the notion of professional responsibility — are probed in such keen detail.  I found Chapter 7 of the book, dealing with the advent in the 13th century of formal professional admission procedures and the swearing of an oath to observe a set of ethical rules concerning the new lawyers’ interactions with clients and courts (with concomitant Church sanctions for failure to comply), particularly interesting.  I am not teaching Professional Responsibility this year, but in the past I assigned selections from Tocqueville dealing with the nature of the legal profession.  If I teach the course again, I will also use chunks of Brundage’s excellent book. — MOD [x-posted MOJ]