Since Cajetan, the central text in considering St. Thomas’s doctrine of analogy has been the Scriptum super Sententiis I d 19 q.5 a. 2. Interpretations of this abound, along with refutations of all of them. Dionne’s explanation of the text is so simple I found myself wondering how there was ever a dispute over it. All one has to do is distinguish the order of names of the order of being.
I cut out two sentences that seemed clunky, and cleaned up some of the syntax to make it more English like. So if you are reading this in the post-apocalyptic world where this is the only version of the text, put me in a footnote somewhere.
3. Super I Sententiarum d. 19 q. 5 a. 2.
Before examining this text, we note that St. Thomas here responds to a difficulty. The difficulty involves the passage from the level of the intentional to the real.
It [the objection] involves asking whether there is only one truth, the uncreated truth. It seems there is. One has said in the previous article, in effect, that that truth is an analogous term. But there is only one health numerically, from which the animal is called healthy since it is the subject, from which medicine is called healthy, since it is the cause, and urine is called healthy, since it is the sign. In the same way, it seems, one needs to say that there is one truth from which all things are called true. We note that in the minor of this argument one treats of predication: true is an analogue. In the major, one treats of reality: the analogue only exists in one. Only the first analogue is possesses the form intrinsically, from which it is denominated. Of all that is called healthy, for example, only the animal possesses health intrinsically. From these two premises, one infers the unity of truth one says that there is only one real truth, just as there is only one real health.
In order to deal with this difficulty, St. Thomas needs to treat of analogy not only in intention, but also analogy secundum esse. He will gather the term analogy in all its possible senses.
St. Thomas distinguishes three ways in which something is said analogously. The first is secundum esse and not secundum intentionem. Since one here excludes the analogy according to being, one could here speak of extrinsic denomination. This happens when the intention relates to many inferiors according to a certain order, but which has being only in one. This is the case of health, which relates to the animal, the medicine and the urine in a certain order, but exists only in the animal.
The second kind of analogy is secundum esse and not secundum intentionem. This happens when many inferiors relate to some common intention. The being is nevertheless not common in all. For example, we can consider body as it is said of corruptible and incorruptible things, according to the understanding of the ancients. Logically, it is a univocal name. But with respect to the natures, there is not question of considering them wholly univocal.
Last, the third way of speaking about analogy is secundum esse and secundum intentionem. There one has equality neither in the intention of the name, nor in being. This is the case with the word being, which is said of substance and accident. One has a common nature that has some existence in any of its inferiors, but is different relative to whether there is more or less perfection. We nevertheless note that for the logician the fact that the analogy secundum esse is imposed on the analogy secundum intentionem does not make the word analogous. The moment one has a non-equality in a common intention, one has an analogous term; this inequality on the level of representation suffices for the doctrine of analogy as such. In the case of health and of being, the word “analogy” is said indifferently. But if one is forced to consider conditions on the side of things, he needs to use the example of health being an analogy secundum intentionem only and being being secundum esse and secundum intentionem.