Bk 3 Q 7 A 3 Thes p 14
ARTICLE III

Is God Contained in a Genus?

Sum. Th. I, Q. iii, A. 5

THE third point of inquiry is whether God is contained in a genus: and seemingly he is.

Bk 3 Q 7 A 3 Obj 1 p 14
1. Damascene says (De Fide Orth. iii, 4): Substance in God denotes the common species of the three Persons like in species: hypostasis signifies an individual, for instance the Father, Son and Holy Ghost, Peter or Paul. Thus God is compared to the Father, Son and Holy Ghost as a species to individuals. Now wherever there is a species with individuals, there is a genus: since the species is composed of genus and difference. Therefore seemingly God is contained in a genus.

Bk 3 Q 7 A 3 Obj 2 p 14
2. Things which are in no way different are identical. But God is not identical with other things: therefore in some way he is different from them. Now that which is different from something else differs therefrom by some difference. Therefore there is a difference in God, whereby he differs from other things. But it is not an accidental difference, since nothing in God is accidental, as Boethius says (De Trin.). And every substantial difference makes a division of a genus. Therefore God is contained in a genus.

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3. Things may be the same either in genus, or in species, or in individual (Topic. i, 6). Therefore things may also differ in these ways, since if one of two opposites admits of multiplicity, the other does so too. Therefore God is distinct from a creature either in individual only, or in number and species, in which case he will be in the same genus as the creature, and consequently will be contained in a genus: or he will differ from the creature in genus, and then he will be in another genus from the creature: because diversity results from numbers, so that difference of genus implies a number of genera. Therefore in any case God must be contained in a genus.

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4. Anything to which the generic difference of substance applies belongs to the genus (of substance). Now the generic difference of substance is self-subsistence, which is most applicable to God. Therefore God is in the genus of substance.

5. Anything that can be defined must be in a genus.

Bk 3 Q 7 A 3 Obj 5. p 15
5. Now God can be defined, for he is said to be pure act. Therefore God is contained in a genus.

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6. Whatsoever is predicated of another essentially and of other things besides, is compared to that thing either as its species or as its genus. Now all things predicated of God are predicated of him essentially, since all the predicaments when applied to God refer to his essence, as Boethius says (De Trin.). And it is clear that they are applicable not only to God but to other things besides. Therefore they are compared to God either as the species to the individual, or as the genus to its species, and in either case God must be contained in a genus.

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7. A thing is measured by a measure of its own genus (Metaph. x). Now according to the Commentator (ibid.) God is the measure of all substances. Therefore God is in the same genus as other substances.

Bk 3 Q 7 A 3 OTC p 15
On the contrary whatsoever is contained in a genus contains something in addition to the genus, and therefore is composite. But God is utterly simple. Therefore he is not contained in a genus.

Bk 3 Q 7 A 3 OTC p 15
Moreover, whatsoever is contained in a genus can be defined, or else comprised under something that is defined. But this cannot apply to God since he is infinite. Therefore he is not in a genus.

I answer that God is not contained in a genus. For the present this may be proved by three arguments. First, nothing is affirmed in a genus by reason of its being but by reason of its quiddity. And, this is clear because the being of each thing is proper to it and distinct from the being of any other thing. But the notion of substance can be common. Because of this the Philosopher [Metaph. 3.2] also says that a being is not a genus. Now God is his own being; hence he cannot be in a genus.
I answer that God is not contained in a genus, and for the nonce this may be proved by three arguments. The first argument is that nothing is assigned to a genus by reason of its being but by reason of its quiddity; and this is clear from the fact that the being of a thing is proper to that thing and distinct from the being of anything else: whereas the essence may be common. Hence the Philosopher (Metaph. ii, 3) says that being is not a genus. Now God is Being itself: wherefore he cannot be in a genus.

The second reason is that although matter is not a genus nor form a difference, nevertheless the notion of the genus is taken from the matter, and the notion of the difference from the form: for instance, in man the sensible nature whence he derives his animality is material in relation to his reason whence derives the difference of rationality. For an animal is that which has a sensitive nature, and a rational being is one that has reason. Hence in everything that is contained in a genus there must be composition of matter and form, or of act and potentiality: and this cannot be in God who is pure act as we have shown (A. 1). Therefore he cannot be in a genus. The third reason is that as God is simply perfect he contains the perfections of all genera: for this is what is meant by being simply perfect (Metaph. v). Now that which is contained in a genus is confined within the limits of that genus. Wherefore God cannot be in a genus: for in that case his essence would not be infinite nor absolutely perfect, but his essence and perfection would be confined within the limits of a definite genus.

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Hence it is also evident that God is neither a species nor an individual, nor is there difference in him. Nor can he be defined, since every definition is taken from the genus and species. Wherefore neither can we demonstrate anything about him save from his effects, since the middle proposition of an a priori demonstration is a definition.

Bk 3 Q 7 A 3 Rp 1 p 16
Reply to the First Objection. Damascene uses the word species metaphorically and not in the strict sense. God's name (i.e. God) is like a species in that it is predicated essentially of several distinct individuals: but it cannot be called a species strictly speaking, since a species is not identically the same in each individual but only logically: whereas the same identical divine essence is common to the three Persons: wherefore Father, Son and Holy Ghost are one God, but Peter, Paul and Mark are not one man.

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Reply to the Second Objection. A distinction is to be noted between difference and diversity according to the Philosopher (Metaph. x). Diversity is absolute and is applied to things which are not the same: whereas difference is relative, since that which is different differs in a certain respect. Accordingly if we take the term different strictly, it is not true that things which are in no way different are the same: but if we take the term differentin a broad sense it is true: and in this sense we grant that God differs from other things. It does not follow, however, that he differs by reason of a difference, but that he differs from other things by reason of his essence: for this must needs be the case in first principles and simple things. Thus man differs from a donkey by the difference of rationality: but rationality is not distinguished from a donkey by a still further difference (since thus there would be no end to the process), for it differs therefrom by itself.

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Reply to the Third Objection. God is said to be diverse in genus from the creature, not as though he were contained in another genus, but because he is altogether outside a genus.

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Reply to the Fourth Objection. According to Avicenna (Metaph. iii, 8) substance is not rightly defined as a self-subsistent being: for being cannot be the genus of a thing according to the Philosopher (Metaph. ii, 3), because nothing can be added to being that has not a share of being, and a difference should not be a part of the genus. If, however, substance can be defined notwithstanding that it is the most universal of genera, its definition will be a thing whose quiddity is competent to have being not in a subject.††1 Hence the definition of substance cannot be applied to God, whose quiddity is not distinct from his being. Wherefore God is not contained in the genus of substance but is above all substance.

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Reply to the Fifth Objection. God cannot be defined: because whatsoever is defined is comprehended by the intellect of him that defines it; and God is incomprehensible to the intellect. Hence it is not a definition of God when we say that he is pure act.

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Reply to the Sixth Objection. It is essential to a genus that it be predicated univocally. Now nothing can be predicated univocally of God and the creature, as we shall prove further on (A. 7). Hence although things predicated of God are predicated of him substantially they are not predicated of him generically.

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Reply to the Eighth Objection. Although God does not belong to the genus of substance as contained in a genus, as a species or an individual is contained in a genus: yet we may say that he is in the genus of substance by reduction as its principle, even as a point is in the genus of continuous quantity, and unity in the genus of number. In this way he is the measure of all substances, as unity is the measure of all numbers.