Chapter 4.--The Same Argument Continued.
6. For in like manner the virtues which are in the human mind, although each has its own several and different meaning, yet are in no way mutually separable; so that, for instance, whosoever were equal in courage, are equal also in prudence, and temperance, and justice. For if you say that such and such men are equal in courage, but that one of them is greater in prudence, it follows that the courage of the other is less prudent, and so neither are they equal in courage, since the courage of the former is more prudent. And so you will find it to be the case with the other virtues, if you consider them one by one. For the question is not of the strength of the body, but of the courage of the mind. How much more therefore is this the case in that unchangeable and eternal substance, which is incomparably more simple than the human mind is? Since, in the human mind, to be is not the same as to be strong, or prudent, or just, or temperate; for a mind can exist, and yet have none of these virtues. But in God to be is the same as to be strong, or to be just, or to be wise, or whatever is said of that simple multiplicity, or multifold simplicity, whereby to signify His substance. Wherefore, whether we say God of God in such way that this name belongs to each, yet not so that both together are two Gods, but one God; for they are in such way united with each other, as according to the apostle's testimony may take place even in diverse and differing substances; for both the Lord alone is a Spirit, and the spirit of a man alone is assuredly a spirit; yet, if it cleave to the Lord, "it is one spirit:" how much more there, where there is an absolutely inseparable and eternal union, so that He may not seem absurdly to be called as it were the Son of both, when He is called the Son of God, if that which is called God is only said of both together. Or perhaps it is, that whatever is said of God so as to indicate His substance, is not said except of both together, nay of the Trinity itself together? Whether therefore it be this or that (which needs a closer inquiry), it is enough for the present to see from what has been said, that the Son is in no respect equal with the Father, if He is found to be unequal in anything which has to do with signifying His substance, as we have already shown. But the apostle has said that He is equal. Therefore the Son is equal with the Father in all things, and is of one and the same substance.
Chapter 5.--The Holy Spirit Also is Equal to the Father and the Son in All Things.
7. Wherefore also the Holy Spirit consists in the same unity of substance, and in the same equality. For whether He is the unity of both, or the holiness, or the love, or therefore the unity because the love, and therefore the love because the holiness, it is manifest that He is not one of the two, through whom the two are joined, through whom the Begotten is loved by the Begetter, and loves Him that begat Him, and through whom, not by participation, but by their own essence, neither by the gift of any superior, but by their own, they are "keeping the unity of the Spirit in the bond of peace;" [611] which we are commanded to imitate by grace, both towards God and towards ourselves. "On which two commandments hang all the law and the prophets." [612] So those three are God, one, alone, great, wise, holy, blessed. But we are blessed from Him, and through Him, and in Him; because we ourselves are one by His gift, and one spirit with Him, because our soul cleaves to Him so as to follow Him. And it is good for us to cleave to God, since He will destroy every man who is estranged from Him. Therefore the Holy Spirit, whatever it is, is something common both to the Father and Son. But that communion itself is consubstantial and co-eternal; and if it may fitly be called friendship, let it be so called; but it is more aptly called love. And this is also a substance, since God is a substance, and "God is love," as it is written. [614] But as He is a substance together with the Father and the Son, so that substance is together with them great, and together with them good, and together with them holy, and whatsoever else is said in reference to substance; since it is not one thing to God to be, and another to be great or to be good, and the rest, as we have shown above. For if love is less great therein [i.e. in God] than wisdom, then wisdom is loved in less degree than according to what it is; love is therefore equal, in order that wisdom may be loved according to its being; but wisdom is equal with the Father, as we have proved above; therefore also the Holy Spirit is equal; and if equal, equal in all things, on account of the absolute simplicity which is in that substance. And therefore they are not more than three: One who loves Him who is from Himself, and One who loves Him from whom He is, and Love itself. And if this last is nothing, how is "God love"? If it is not substance, how is God substance?
[611] Eph. iv. 3
[612] Matt. xxii. 37-40
[614] 1 John iv. 16