John Duns Scotus was called "Doctor Subtilis" (the Subtle Doctor), and the title describes the man to the letter. The complexity of his thought and the presence of what can only be termed an absolute glut of distinctions were the bane of friend and foe alike. In 1678 a disciple produced a manual which he felt called upon to announce as The Theology of Scotus Delivered from Prolixity and Obscurity, and Its Subtlety Vindicated. It met with limited success, and that, one may surmise, only with those who already counted themselves among Duns Scotus's staunchest supporters. For others, he was forever the original "dunce" ("Duns man"), and no appeal to his learning or wisdom could rescue the name from this ignominious association. When, in the same century in which the disciple's book appeared, a certain lawyer was called "a dunce," he sued and won in spite of the defendant's...