CHAPTER XXV—That God is not in any Genus

EVERYTHING that is in any genus has something in it whereby the nature of the genus is characterised and reduced to species: for there is nothing in the genus that is not in some species of it. But this is impossible in God, as has been shown in the previous chapter.

2. If God is in any genus, He is either in the genus of accident or the genus of substance. He is not in the genus of accident, for an accident cannot be the first being and the first cause. Again, He cannot be in the genus of substance: for the substance that is a genus is not mere existence⁵³⁵³There is always an ambiguity in this term of ‘mere existence,’ ipsum esse, αὐτὸ τὸ εἶναι. Either it means ens abstractissimum, the thinnest and shallowest of concepts, denoting the barest removal from nothingness: or it is ens plenissimum, being that includes (virtually at least) all other being, as the Platonic αὐτὸ τὸ καλόν virtually includes all beauty. In this latter sense the term is predicable of God alone. In God ‘mere existence’ means pure actuality.: otherwise every substance would be its own existence, since the idea of the genus is maintained in all that is contained under the genus: at that rate no substance 20would be caused by another, which is impossible (Chap. XIII, XV). But God is mere existence: therefore He is not in any genus.

3. Whatever is in a genus differs in point of existence from other things that are in the same genus: otherwise genus would not be predicated of several things. But all things that are in the same genus must agree in the quiddity, or essence, of the genus: because of them all genus is predicated so as to answer the question what (quid) each thing is.⁵⁴⁵⁴Quod quid est, τὸ τί ἦν εἶναι, where quod is a clumsy equivalent for τό. Therefore the existence of each thing that exists in a genus is something over and above the quiddity of the genus. But that is impossible in God.⁵⁵⁵⁵God is mere and sheer existence, not existence modelled upon some quiddity (Chap. XXII). In this study it should be borne in mind that ‘essence’ represents the ideal order: ‘existence’ the actual. God is the unity of essence and existence, of the ideal and the actual; the point at which the potential finally vanishes into the actual. In every existent being, under God, there is an admixture of potentiality. This is to be kept steadily in view in bringing St Thomas to bear upon Kant and Hegel.

4. Everything is placed in a genus by reason of its quiddity. But the quiddity of God is His own mere (full) existence⁵⁶⁵⁶If God and the creatures were included in one genus, the genus could not he the ‘full existence’ (esse plenissimum) of God, for that is not predicable of the creature. We should have to fall back upon the other meaning of ipsum esse, namely, ‘bare existence,’ and upon that St Thomas argues.. Now a thing is not ranked in a genus on the score of mere (bare) existence: otherwise ‘being,’ in the sense of mere (bare) existence, would be a genus. But that ‘being’ cannot be a genus is proved in this way. If ‘being’ were a genus, some differentia would have to be found to reduce it to species. But no differentia participates in its genus: I mean, genus is never comprehended in the idea of the differentia: because at that rate genus would be put twice over in the definition of the species.⁵⁷⁵⁷As if we took ‘living’ for a differentia attachable to the genus ‘animal,’ and so formed a species ‘living animal.’ Differentia then must be something over and above what is understood in the idea of genus. Now nothing can be over and above what is understood by the idea of ‘being’; since ‘being’ enters into the conceivability of all things whereof it is predicated, and thus can be limited by no differentia.⁵⁸⁵⁸Being means anything and everything that in any way is, and can at all be said to be removed from the merest nothing. There is being in thought, conceptual, or ideal being; and there is being of thing, — actually existent being. Being in this latter sense of what actually exists cannot be a genus, because the whole apparatus of genus, species and differentia belongs to the business of definition; and definition does not lay down actual existence (esse), but ideal being (essentia). It is no part of the definition of a triangle to state that any such things as triangles do actually exist. Therefore we read in this chapter (n. 3): “The existence of each thing that exists in a genus is something over and above the quiddity of the genus.” In other words, ‘existence’ lies outside every possible generic notion. Nor again can being in the sense of what is in thought be a genus, because such conceptual being penetrates and pervades the whole ideal order, to which genus, species and differentia belong: it is the fundamental notion of the order, and appears everywhere, and therefore cannot be screened off as a genus. — See Metaphysics in the Stonyhurst Series of “Manuals of Catholic Philosophy,” pp. 35-38.

Hence it is also apparent that God cannot be defined, because every definition is by genus and differentias. It is apparent also that there can be no demonstration of God except through some effect of His production: because the principle of demonstration is a definition of the thing defined.⁵⁹⁵⁹God cannot be demonstrated in the Aristotelian sense, as truths are demonstrated in the exact sciences, notably mathematics. You can demonstrate in this sense nothing but what you thoroughly comprehend.