Further Interlude, still on Analogy, from the Ox

Just in case you did not, in fact, read it all:

Univocal predication is impossible between God and creatures. The reason of this is that every effect which is not an adequate result of the power of the efficient cause, receives the similitude of the agent not in its full degree, but in a measure that falls short, so that what is divided and multiplied in the effects resides in the agent simply, and in the same manner; as for example the sun by exercise of its one power produces manifold and various forms in all inferior things. In the same way, as said in the preceding article, all perfections existing in creatures divided and multiplied, pre-exist in God unitedly. Thus when any term expressing perfection is applied to a creature, it signifies that perfection distinct in idea from other perfections; as, for instance, by the term “wise” applied to man, we signify some perfection distinct from a man’s essence, and distinct from his power and existence, and from all similar things; whereas when we apply to it God, we do not mean to signify anything distinct from His essence, or power, or existence. Thus also this term “wise” applied to man in some degree circumscribes and comprehends the thing signified; whereas this is not the case when it is applied to God; but it leaves the thing signified as incomprehended, and as exceeding the signification of the name. Hence it is evident that this term “wise” is not applied in the same way to God and to man. The same rule applies to other terms. Hence no name is predicated univocally of God and of creatures.

Neither, on the other hand, are names applied to God and creatures in a purely equivocal sense, as some have said. Because if that were so, it follows that from creatures nothing could be known or demonstrated about God at all; for the reasoning would always be exposed to the fallacy of equivocation. Such a view is against the philosophers, who proved many things about God, and also against what the Apostle says: “The invisible things of God are clearly seen being understood by the things that are made” (Romans 1:20). Therefore it must be said that these names are said of God and creatures in an analogous sense, i.e. according to proportion.

Now names are thus used in two ways: either according as many things are proportionate to one, thus for example “healthy” predicated of medicine and urine in relation and in proportion to health of a body, of which the former is the sign and the latter the cause: or according as one thing is proportionate to another, thus “healthy” is said of medicine and animal, since medicine is the cause of health in the animal body. And in this way some things are said of God and creatures analogically, and not in a purely equivocal nor in a purely univocal sense. For we can name God only from creatures (Article 1). Thus whatever is said of God and creatures, is said according to the relation of a creature to God as its principle and cause, wherein all perfections of things pre-exist excellently. Now this mode of community of idea is a mean between pure equivocation and simple univocation. For in analogies the idea is not, as it is in univocals, one and the same, yet it is not totally diverse as in equivocals; but a term which is thus used in a multiple sense signifies various proportions to some one thing; thus “healthy” applied to urine signifies the sign of animal health, and applied to medicine signifies the cause of the same health.

(source: Summa Theologica I.13.5 respondeo)