Objection 1. It seems that the things attributed to God and creatures are univocal. For every equivocal term is reduced to the univocal, as many are reduced to one; for if the name "dog" be said equivocally of the barking dog, and of the dogfish, it must be said of some univocally--viz. of all barking dogs; otherwise we proceed to infinitude. Now there are some univocal agents which agree with their effects in name and definition, as man generates man; and there are some agents which are equivocal, as the sun which causes heat, although the sun is hot only in an equivocal sense. Therefore it seems that the first agent to which all other agents are reduced, is an univocal agent: and thus what is said of God and creatures, is predicated univocally.
Objection 2. Further, there is no similitude among equivocal things. Therefore as creatures have a certain likeness to God, according to the word of Genesis (Genesis 1:26), "Let us make man to our image and likeness," it seems that something can be said of God and creatures univocally.
Objection 3. Further, measure is homogeneous with the thing measured. But God is the first measure of all beings. Therefore God is homogeneous with creatures; and thus a word may be applied univocally to God and to creatures.
On the contrary, whatever is predicated of various things under the same name but not in the same sense, is predicated equivocally. But no name belongs to God in the same sense that it belongs to creatures; for instance, wisdom in creatures is a quality, but not in God. Now a different genus changes an essence, since the genus is part of the definition; and the same applies to other things. Therefore whatever is said of God and of creatures is predicated equivocally.
Further, God is more distant from creatures than any creatures are from each other. But the distance of some creatures makes any univocal predication of them impossible, as in the case of those things which are not in the same genus. Therefore much less can anything be predicated univocally of God and creatures; and so only equivocal predication can be applied to them.
I answer that, 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.
I answer that, An aureole is not due to the angels. The reason of this is that an aureole, properly speaking, corresponds to some perfection of surpassing merit. Now those things which make for perfect merit in man are connatural to angels, or belong to their state in general, or to their essential reward. Wherefore the angels have not an aureole in the same sense as an aureole is due to men.
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 (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.
Reply to Objection 1. Although equivocal predications must be reduced to univocal, still in actions, the non-univocal agent must precede the univocal agent. For the non-univocal agent is the universal cause of the whole species, as for instance the sun is the cause of the generation of all men; whereas the univocal agent is not the universal efficient cause of the whole species (otherwise it would be the cause of itself, since it is contained in the species), but is a particular cause of this individual which it places under the species by way of participation. Therefore the universal cause of the whole species is not an univocal agent; and the universal cause comes before the particular cause. But this universal agent, whilst it is not univocal, nevertheless is not altogether equivocal, otherwise it could not produce its own likeness, but rather it is to be called an analogical agent, as all univocal predications are reduced to one first non-univocal analogical predication, which is being.
Reply to Objection 2. The likeness of the creature to God is imperfect, for it does not represent one and the same generic thing (4, 3).
Reply to Objection 3. God is not the measure proportioned to things measured; hence it is not necessary that God and creatures should be in the same genus.
The arguments adduced in the contrary sense prove indeed that these names are not predicated univocally of God and creatures; yet they do not prove that they are predicated equivocally.
Source: Summa Theologica (New Advent)