“Do you think that you understand what you read?”
“How can I, unless some man guide me?”
[Acts 8:30, slightly paraphrased]
My current autodidactic enterprise is to work through Aristotle, guided by Aquinas’ commentaries on his works (where they exist—Aquinas did not write commentaries on everything Aristotle wrote). This is a venture I decided upon sometime last year after reading a couple excellent books by Ed Feser (whose equally excellent blog is here). I read the Basic Works several years ago as a prelude to reading the Summa Theologiae, but I knew even then that I didn’t understand them terribly well. Feser made Aristotelian philosophy so clear that I knew I owed Aristotle another reading, and it only made sense to me to be guided by Aquinas—surely one of the greater students in history of The Philosopher. So here I am.
Aquinas wrote no commentary on The Categories, so I read that on my own and then followed that up with De Interpretatione. I thought I understood the former somewhat, but I didn’t understand its purpose: How are discussions of homonyms, substances, quantity, relations, and so forth connected with categories? And similarly with De Interpretatione: what does an extended discussion of the relationships between affirmations and negations have to do with hermeneutics (the Greek name for the book being Perihermeneias)?
And then I started reading Aquinas’ commentary on De Interpretatione. Wow. I didn’t have to read more than a page to learn that my understanding of the two books was being overly influenced by their titles:
1.There is a twofold operation of the intellect, as the Philosopher says in III De anima [6: 430a 26]. One is the understanding of simple objects, that is, the operation by which the intellect apprehends just the essence of a thing alone; the other is the operation of composing and dividing. There is also a third operation, that of reasoning, by which reason proceeds from what is known to the investigation of things that are unknown. The first of these operations is ordered to the second, for there cannot be composition and division unless things have already been apprehended simply. The second, in turn, is ordered to the third, for clearly we must proceed from some known truth to which the intellect assents in order to have certitude about something not yet known.
2. Since logic is called rational science it must direct its consideration to the things that belong to the three operations of reason we have mentioned. Accordingly, Aristotle treats those belonging to the first operation of the intellect, i.e., those conceived by simple understanding, in the book Praedicamentorum [The Categories – FN]; those belonging to the second operation, i.e., affirmative and negative enunciation, in the book Perihermeneias [De Interpretatione]; those belonging to the third operation in the book Priorum [Prior Analytics] and the books following it in which he treats the syllogism absolutely, the different kinds of syllogism, and the species of argumentation by which reason proceeds from one thing to another. And since the three operations of reason are ordered to each other so are the books: the Praedicamenta to the Perihermeneias and the Perihermeneias to the Priora and the books following it.
Well, that certainly helped. “Categories” doesn’t exactly denote “simple objects,” although a category can consist of them, and “interpretation” isn’t exactly related to affirmations and negations per se—certainly not in the way that Aristotle addresses them. In the introduction to his commentary, St Thomas made me realize that I need to pay less attention to the titles of Aristotle’s works (which are probably late additions anyway, and the etymology or modern denotations of which won’t really help explain what he actually said) and more to the works themselves. This is made all the more clear in what Aquinas says next about De Interpretatione:
3. The one we are now examining is named Perihermeneias, that is, On Interpretation. Interpretation, according to Boethius, is “significant vocal sound—whether complex or incomplex—which signifies something by itself.”
That’s not what interpretation means today!
Therefore, only enunciative speech in which truth or falsity is found is called interpretation. Other kinds of speech, such as optatives and imperatives, are ordered rather to expressing volition than to interpreting what is in the intellect. This book, then, is entitled On Interpretation, that is to say, On Enunciative Speech in which truth or falsity is found. [emphasis added]
Aquinas classifies the book among Aristotle’s works on logic. That alone helps to explain its purpose, and this is exactly what I hoped to gain from his commentaries: guidance. Thank you St Thomas!