Thomas Aquinas’s Doctrine of Analogy

[I’ve been busy finishing up my Master’s thesis, so posts here have been sparse. I’m almost done, so expect more stuff here soon. In the mean time here’s a taste of some of what I’ve been working on to slake your thirst for medieval theology. This is the second half of my second chapter, so if you see something obviously wrong–let me know. Unfortunately the tasty, tasty footnotes did not survive the transition to HTML.]

2.2 Thomas Aquinas

This second half of chapter two briefly investigates two aspects of Thomas’s thought crucial for the interpretation of Henry of Ghent. The first is Thomas’s elaboration of the doctrine of analogy. The second aspect of Thomas’s thought important for Henry is Thomas’s response to Avicenna’s circularity objection and his reduction of Avicenna’s ens commune to created being.

Besides the already thorny philosophical problems raised by Avicenna’s interpretation of Aristotle, the exigencies of Christian theology adds another dimension to the problem of analogy for Thomas and Henry. How is it possible to use words drawn from composite, finite, immanent creatures to make positive affirmations about an infinite, simple, transcendent God? Henry and Thomas both use the doctrine of analogy to resolve not only the question of the subject matter of metaphysics, but this additional problem about the adequacy of theological language.

There are two major texts upon which this interpretation of Thomas’s doctrine of analogy will be based. The first is d. 19, q. 5 of the first book of his Sentences commentary and the second is a. 13 of the prima pars of the Summa Theologiae. Because the Sentences text is earlier, it will be treated first. The third subsection will apply Thomas’s understanding of analogy to his views on the subject of metaphysics based on his Metaphysics commentary.


2.2.1 I Sent. d. 19, q. 5

In d. 19, q. 5, a. 2 Thomas considers the question whether all things are true by uncreated truth. (Utrum omnia sint vera veritate increata?) The first argument that all things are true by uncreated truth uses the familiar Aristotelian medical example: just as health is numerically one thing by which the health of an animal, his urine and his diet are all called healthy, so are all things said to be true by the one uncreated notion of truth.

In response to this argument, Thomas notes that a term can be analogous between two things in three ways:

(1) Secundum intentionem et non secundum esse.
(2) Secundum esse et non secundum intentionem.
(3) Secundum intentionem et secundum esse.

Thomas says case (1) obtains when “one intention is referred to many things per prius et posterius” as the intention of health is referred to an animal, urina and diet in different ways.

Case (2) obtains when “many are made equal in the intention of some common feature, but that common feature does not exist in one ratio in all of them. . .“ Thus a logician would say that “body” is predicated univocally of bodies, even though the metaphysician or physicist, considering a thing according to its esse, knows that in reality “body” is not one genus because there is not one single (metaphysical) genus under which both corruptible bodies and incorruptible bodies fall.

Case (3) obtains when the things analogous related are the same neither in one common intention, nor in being. The term “ens” predicated analogously of substances and accidents is one example of an analogy secundum intentionem et secundum esse. In the same way the terms “true,” “beautiful” and all other terms analogically predicated of God and creatures are predicated secundum intentionem and secundum esse. Thus, the argument that all things are true by uncreated truth was incorrect because the term “true” is predicated of both God and creatures secundum intentionem et secundum esse (Case 3) rather than secundum intentionem et non secundum esse (Case 1).

But why is there an analogy between God and creatures secundum esse et secundum intentionem (Case 3) instead of (Case 1) following the traditional Aristotelian medical example? Montagnes answers that medicine proposes a model of analogy ad unum which is concerned with an extrinsic attribution. The healthiness of a given plant comes from something else, namely the aptitude of a certain kind of body to receive the plant as a medicine. The analogy of being, on the other hand, works by an intrinsic attribution: God is the primary instance of being because he is being per essentiam, and creatures are secondary because they are beings per participationem. Only the analogy secundum esse et secundum intentionem can guarantee this intrinsic relationship between participating and participated being. For the Thomas of the Sentences, according to Montagnes, creaturely participation in divine being grounds the analogical relation between them.

It seems then that Thomas is following Avicenna by not allowing an analogy according to extrinsic attribution to explain the relationship between the being of God and the being of creatures. However Avicenna’s rejection of this extrinsic attribution led him to the idea of ens commune as one positive thing which God and creatures seem to share univocally. Thomas, on the other hand, responds to the problem by asserting an intrinsic analogy secundum esse et secundum intentionem between God and creatures in virte of creatures participating in the form of divine being (in a diminished way).

The importance of participation in a. 19 can also be seen from Thomas’s response to the third objection. The hypothetical objector quotes Book VIII of Augustine’s De trinitate, which asks the reader to consider this and that good thing, then abstract from this and that to understand the good itself in which all good things participate, which is God. According to Thomas, however the goodness of a creature is different from the goodness of God insofar as the divine goodness is universal and good in itself whereas created goodnesses are particular and good only by reference to something else (secundum aliquid). We see the divine goodness or truth in particular good or true things in the same way we see an exemplar in something derived from the exemplar. This example asserts something important of the participation of creatures in God: the form of “good,” “true,” “being,” etc. which creatures receive from God is not the same as God. For God is being, good, etc. per essentiam, whereas creatures only possess these forms per participationem by reference to God.

2.2.2 Summa Theologiae 1a, q. 13

Having laid out Thomas’s early position from the Sentences commentary, we can now turn to the Summa Theologiae, q. 13, which is closer in order of composition to the late Metaphysics commentary quoted above. There is not a dramatic change in Thomas’s position between the Sentences commentary and the Summa, but the mature account does develop the position some of the earlier themes more fully.

One such development is the theory of religious language one finds in a. 13, q. 1. Because we can only come to a knowledge of God from creatures, all the names that one can apply to God are derived from creatures (a. 13, q. 2 ad 2). This presents a problem, because the ordinary terms we derive from creatures such as “wise” have modi significandi which implies complexity and subsistence. The only simple terms we can derive from creatures are abstract ones such as “wisdom,” whose modi significandi imply abstraction. According to Ashworth,

It is precisely because of these modi significandi that we have so much difficulty in naming God, who is simple and subsistent at one and the same time. If we apply abstract terms to God, the modus significandi of subsistence is lost and the inappropriate modus significandi is added.

The conclusion Thomas draws from this is that, “neither way of speaking measures up to [God’s] way of being, for in this life we do not know him as he is in himself.”

Lest one think that he relegates theological language to a purely negative role, Thomas hastens to add in the next article that creaturely words can express a truth about God because creatures receive their perfections from God:

Any creature, in so far as it possesses any perfection, represents God and is like to him, for he, being simply and universally perfect, has pre-existing in himself the perfections of all his creatures as noted above. [1a, q. 4, a. 2] But a creature is not like to God as it is like to another member of its species or genus, but resembles him as an effect may in some way resemble a transcendent cause although failing to reproduce perfectly the form of the cause—as in a certain way the forms of inferior bodies imitate the power of the sun . . . Thus words like ‘good’ and wise’ when used of God do signify something that God really is, but they signify it imperfectly because creatures represent God imperfectly.

In other words, the creaturely word “good” can still express something true about God, namely “God is good” because creaturely goodness is like (similis) God’s goodness, though obviously in a less perfect way.

In a. 5, Thomas rejects the idea that creaturely words like “good” could be predicated univocally of a transcendent God. Nor however, could “good” be totally equivocal between God and creatures, since then there could never be any arguments about God’s goodness, as all such arguments would fall victim to the fallacy of equivocation. The answer then is that theological language is neither equivocal, nor univocal, but analogical.

This way of using words lies somewhere between pure equivocation and simple univocity, for the word is neither used in the same sense (Neque . . . una ratio), as with univocal usage, nor in totally different senses (nec totaliter diversa), as with equivocation. The several senses of a word used analogically signify different relations to some one thing, as ‘health’ in a complexion means a symptom of health in a man, and in a diet means a cause of that health.

Note that Thomas says here that there is not one common ratio God and creatures share. Rather there is a priority and posteriority. God is the primary sense of all positive terms that can be attributed to him because he prepossesses all creaturely perfections, as noted above.

But how does Thomas’s account of analogy play into his understanding of the subject of metaphysics?

2.2.3 Thomas Aquinas on the Subject of Metaphysics

Although Thomas does not answer Avicenna’s circularity objection explicitly, in the proemium of his commentary on the metaphysics he does answer implicitly. Thomas begins by observing that one science considers both a genus and its causes. However, he also agrees with Avicenna that ens commune and not God is the subject of metaphysics. To resolve the tension between these two positions, Thomas reduces Avicenna’s concept of ens commune as a universal intention of all being qua being to one logical intention common to all created being, as a proper effect of God as its cause. Therefore, there can be one science of metaphysics which considers ens commune in the sense of created being as its subject in the technical sense and God as the principle or cause of that subject.

Thomas’s position accords more closely to Aristotle’s own position in Metaphysics IV.1 that metaphysics is a science insofar as it seeks the principles and causes of being, which Avicenna denies. However, in Dumont’s words, Thomas’s solution “violates the requisite generality of the subject with respect to all things considered in the science and is completely inconsistent with the Avicennian reasoning that led to making being the subject of metaphysics in the first place.” If created being is the subject of metaphysics, then there is something sought in the science—God—that does not fall under that subject.
Henry of Ghent will criticize Thomas on this point, as we shall see in chapter 3.

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