[81] And choose, if you like, any art you please, whether trifling or important, and the man, too, who is most excellent, and most highly thought of in regard of his skill in it, [36] and then consider if the professions held out by the art are equal to the performances of the artist; for if you duly examine the matter, you will find that the performance falls short of the profession, not by a small, but by a vast distance, it being almost impossible for a man to be perfect in any art whatever, which is in continual motion like a fountain, and is constantly pouring forth various species of all kinds of speculations.