Tractatus de Deo uno secundum naturam

The divine essence itself is infinite understanding and comprehension.¹

That God is absolute perfection, and consequently absolute truth, and that he is most simple, and that he is spirit infinite in perfection, has been proved in the preceding theses. Because therefore he is spirit, he is understood to be a substance whose life is understanding; because he is most simple, his understanding is the divine substance itself; and likewise he neither is nor can be conceived to be in power, but of necessity is ἐντελέχεια and the purest act of understanding.

Yet because the concept of essence is other than that of understanding, the one is distinguished from the other according to reason. Therefore Being absolute, in comparison with understanding, has the character of knowable object; and because it is Being of infinite perfection, it is infinite also in the character of knowability, or in the character of truth, to which no understanding except an infinite one can be perfectly adequated.

Further, the divine act of understanding is as infinite as the object of understanding is infinite, because it is really the divine essence itself and that object. The act of understanding is therefore perfectly proportioned to its infinite object.

Since, finally, understanding is the adequation of the intellect to the object, where actual infinite understanding is really identical with the infinite object itself according to every aspect of its infinite knowability, there is certainly a perfect adequation of the intellect with the object, as far as the object is knowable. This adequation is and is called comprehension. We understand God, therefore, insofar as he is an act of infinite understanding adequated to himself as the infinitely knowable truth, to be the perfect comprehension of himself; and because the act of understanding is the divine substance itself, he is substantial comprehension of himself.

So that such abstract names may be rightly understood, what we said about the divine simplicity above on p. 306 must be recalled. We use abstract names, namely, to express the divine perfections in some measure, for a double reason: both that we may signify the fullness of perfection, and that we may declare simplicity with every composition, even metaphysical, excluded. We say, e. g.: God is wisdom; because in God there is no wisdom restricted to some degree, but he is the whole reason of absolute wisdom, and because wisdom is not, as in creatures, something superadded to substance and essence, but essence itself, from its intrinsic nature, is wisdom. Therefore in the same way we also use those abstract names which in creatures signify immanent action. God is infinite understanding, volition, efficacy (ἐνέργεια). By these names we signify that understanding and will and omnipotence, just as the essence itself is, so are in intrinsic reason in the perfection of act; not, however, as a faculty which proceeds to the act of understanding, willing, effecting. When therefore it is said that God is substantial comprehension of his essence, this means that the divine essence is the divine intellect, and that the intellect is essentially in the perfection of act, and so is understanding; whence it comes about that the infinite divine understanding is adequated to the infinite divine essence, according to which adequation the understanding is called comprehension.

Corollary. If the divine understanding is considered insofar as in reason it is distinguished from its object, which is the divine essence, it can be compared, by analogy with our knowledge, with direct knowledge; but if understanding is viewed insofar as it is the divine essence itself, and so is object to itself, there corresponds to it analogically reflex knowledge, by which we know our own act of knowing.