The most obvious point of contact between St. Thomas and Boethius is the commentaries the former wrote on the latter. As has been noted, we have an incomplete commentary on the De trinitate and a complete exposition of the De hebdomadibus. Discussions have arisen as to the similarities between the thought of Thomas and Boethius, and such discussions are most pointed when they refer to a Boethian text and a comment of Thomas on it. As we will see, Thomists have adopted a very cavalier attitude toward Thomas’s commentaries on Boethius, particularly that on the De hebdomadibus. It has become...

Porphyry wrote his Introduction or Isagoge to the Categories of Aristotle in order to deal with what came to be called the five predicables: genus, species, difference, property and accident. Without prior knowledge of these, Porphyry felt, it would be very difficult for a beginner to follow Aristotle’s book. Given that purpose, Porphyry did not want to make his introduction itself overly demanding. Thus it was that he set aside an issue of great moment in order to get immediately to work.

Now concerning genera and species I beg off asking whether they subsist or are in mere understanding alone,...

Boethius wrote five theological tractates or opuscula sacra and St. Thomas commented on two of them. In this chapter, after several preliminary considerations, we will take a close look at St. Thomas’s commentary on De trinitate. Among the preliminary things we must consider are, first of all, the nature of the tractates and their place in the Boethian literary production. We must also notice that Thomas did not write the same kind of commentary on the two Boethian tractates on which he did comment; that on De trinitate is far freer and more extensive in its plan—we remember that...

The division of the theoretical that Boethius sets down at the outset of Chapter Two of De trinitate has obvious roots in Aristotle, as we shall see, but before looking into that we must take into account another and earlier and manifestly different division of the theoretical, that found in Boethius’s first commentary on Porphyry. In De trinitate, there is a double criterion at work: the way things exist, the way they are considered by us. The earlier division appears to have a much simpler basis: tot speculatiuae philosophiae species, quot sunt res in quibus iustae speculatio considerationis habetur.¹ Does...

Thomas’s commentary on Boethius’s De trinitate has occasioned claims that the metaphysics of Thomas is fundamentally different from that of Aristotle. The articles that stand at the beginning of this development, those of Robert and Geiger,¹ draw attention to the distinction made in the course of Question 5, Article 3, between abstractio and separatio. Geiger bases his remarks on the holograph as well and is thus able to show that the approach taken in the final version of the body of the article was one Thomas hit upon only after a certain amount of searching. Not that the two articles,...

This part is devoted to three things. First, a rapid survey of scholarly opinion on the third Boethian tractate which the medievals called De hebdomadibus. Second, a look at the tractate through the eyes of St. Thomas Aquinas. Third, a brief indication of discussions of the good by Boethius and St. Thomas in other places. The deficiencies of the other interpretations will become clear and we will see that better than anyone else St. Thomas enables us (a) to understand the Boethian tractate in itself and (b) to place the solution the tractate reaches in a broader context, as an...

Boethius will address the question how it is that substances are good insofar as they exist without being, for all that, substantial goods: modum quo substantiae in eo quod sint bonae sint, cum non sint substantialia bona. (ll. 2–4)¹ His method will be that employed in mathematical and other disciplines; he will first set down certain rules and terms (terminos regulasque) and develop a solution in accord with them.

What he means by “rules and terms” is quickly made clear. They are instances of those common conceptions of the mind which, when expressed, gain immediate assent. Communis animi conceptio...

If one searched the Boethian tractate for a ratio boni, some expression or account that could be substituted for “good,” he would come back with his hands empty. Well, not entirely. The Aristotelian account is implicit in the argument developed in the course of stating the problem. Bonum est quod omnia appetunt. We might perhaps find intimations of bonum est diffusivum sui as well in the tractate. But what are we to understand by “Whatever is is good” let alone “Guinness is good for you?”

Boethius warned us at the outset that he was going to be oblique and elusive....