Chapter 56 — That no created intellect, in seeing God, sees all that can be seen in him

Hence it is clear that though the created intellect may see the divine substance, it knows not all that can be seen in the divine substance.

For then alone does it necessarily follow that if one principle be known, all its effects are known in it, when that principle is comprehended by the intellect, because a principle is known as to its whole power when all its effects are known from it. Now other things are known from the divine essence, as effects are known from their cause. Consequently, since the created intellect cannot know the divine substance so as to comprehend it, it does not follow that because it sees it, it sees also all that can be known in it.

Again. The higher the intellect, the more it knows—either a greater number of things, or at least more about the same things. Now the divine intellect surpasses every created intellect: consequently, it knows more things than any created intellect. Yet it does not know things except through knowing its own essence, as we proved in the first book. (Ch. 49.) Therefore, more things are knowable in the divine essence than any created intellect can see in them.

Besides. The measure of a power is according to what it can do. Consequently, to know all that a power can do is the same as to comprehend that power. But, since the divine power is infinite, no created intellect can comprehend it any more than it can comprehend its essence, as we proved above. (Ch. 55.) Neither, therefore, can a created intellect know all that the divine power can do. Yet all the things that the divine power can do are knowable in the divine essence, because God knows them all, and not otherwise than in his essence. Therefore, a created intellect does not see all that can be seen in the divine substance by seeing the divine essence.

Moreover. No cognitive power knows a thing except under the aspect of its proper object: thus by sight we do not know a thing except as colored. Now the proper object of the intellect is what a thing is (that is, the essence of a thing), as stated in 3 De Anima. (On the Soul 3.4.) Consequently, whatever the intellect knows of a thing, it knows it through the knowledge of its essence, so that whenever by demonstration we become acquainted with the proper accidents of a thing, we take what that thing is as principle, as stated in 1 Posterior Analytics. (Posterior Analytics 1.1, 4.) On the other hand, if the intellect knows the essence from its accidents, according to the statement in 1 De Anima, that accidents are a great help in knowing what a thing is, (On the Soul 1.1.) this is accidental insofar as the knowledge of the intellect arises from the senses, and so by knowing the accidents as perceived by the senses we need to arrive at knowing the substance. For this reason this does not occur in mathematics, but only in physics. Consequently, whatever cannot be known in a thing by knowing its substance must be unknown to the intellect.

Now by knowing the substance of one who wills, we cannot arrive at knowing what he wills, because the will does not tend altogether naturally to that which it wills; for which reason the will and nature are said to be two active principles. Therefore, the intellect cannot know what a person wills, except that it may do so from certain effects: thus if we see a person working willingly, we know what he willed. Or again from a cause: thus God knows what we will, as also other of his effects, in that he is the cause of our willing. Or again by someone insinuating his will to another, as when by speaking he makes known his likes and dislikes. Since, then, many things depend on God’s simple will (as we have partly shown above, (Bk. 1, ch. 81.) and will show yet more clearly further on), (Ch. 64, seqq.) although the created intellect may see the divine essence, it does not know all the things that God sees in his essence.

Someone may object to what has been said that God’s substance is something greater than all the things he can do, or understand, or will, except himself, and hence if the created intellect can see God’s substance, much more can it know all that God either understands, or wills, or can do, except himself.

But, if we consider carefully, to know a thing in itself is not the same as to know it in its cause, since there are things which are easy to know in themselves, but not easy to know in their causes. It is true, then, that to know God in himself is more than to know anything else besides him, if this can be known in itself. But it belongs to a more perfect knowledge to know the divine substance and to see its effects in it than to know the divine substance without seeing its effects in it. And it is possible to see the divine substance without comprehending it. But it is not possible to know all that can be known in that substance without comprehending it, as we have proved.