… is from pages 176-177 the 1987 Liberty Fund edition of the Correspondence of Adam Smith; specifically, it’s from Smith’s September 20th, 1774, letter to Dr. William Cullen:
A degree can pretend to give security for nothing but the science of the graduate; and even at that it can give but a very slender security. For his good sense and discretion, qualities not discoverable by an academical examination, it can give no security at all.
DBx: In this letter Smith focused on degrees in medicine, but his point is general. Concentrated, quality training in a discipline – training guided by skilled and committed teachers and mentors – is extraordinarily helpful for learning that discipline (say, economics). But such training, even when it results in the conferral of a terminal degree, is no guarantee that the student will become competent in the discipline. While the vast majority of economists whom I know understand better than non-economists the workings of the economy, I have encountered quite a few Ph.D’d economists – some very prominent – whose understanding of the logic of markets and commerce is weak.