HOW CAN THE ABSOLUTE BE A CAUSE?
From the 'Quæstiones Disputatæ'
The relations which are spoken of as existing between God and creatures are not really in Him. A real relation is that which exists between two things. It is mutual or bilateral then, only when its basis in both correlates is the same. Such is the case in all quantitive relations. Quantity being essentially the same in all quanta, gives rise to relations which are real in both terms--in the part, for instance, and in the whole, in the unit of measurement and in that which is measured.
But where a relation originates in causation, as between that which is active and that which is passive, it does not always concern both terms. True, that which is acted upon, or set in motion, or produced, must be related to the source of these modifications, since every effect is dependent upon its cause. And it is equally true that such causes or agencies are in some cases related to their effects, namely, when the production of those effects redounds in some way to the well-being of the cause itself. This is evidently what happens when like begets like, and thereby perpetuates, so far as may be, its own species.... There are cases, nevertheless, in which a thing, without being related, has other things related to it. The cognizing subject is related to that which is the object of cognition--to a thing which is outside the mind. But the thing itself is in no way affected by this cognition, since the mental process is confined to the mind, and therefore does not bring about any change in the object. Hence the relation established by the act of knowing cannot be in that which is known.
The same holds good of sensation. For though the physical object sets up changes in the sense-organ, and is related to it as other physical agencies are related to the things on which they act, still, the sensation implies, over and above the organic change, a subjective activity of which the external activity is altogether devoid. Likewise, we say that a man is at the right of a pillar because, with his power of locomotion, he can take his stand at the right or the left, before or behind, above or below. But obviously these relations, vary them as we will, imply nothing in the stationary pillar, though they are real in the man who holds or changes his position. Once more, a coin has nothing to do with the action that gives it its value, since this action is a human convention; and a man is quite apart from the process which produces his image. Between a man and his portrait there is a relation, but this is real in the portrait only. Between the coin and its current value there is a relation, but this is not real in the coin.
Now for the application. God's action is not to be understood as going out from Him and terminating in that which He creates. His action is Himself; consequently altogether apart from the genus of created being whereby the creature is related to Him. And again, he gains nothing by creating, or, as Avicenna puts it, His creative action is in the highest degree generous. It is also manifest that His action involves no modification of His being--without changing, He causes the changeable. Consequently, though creatures are related to Him, as effects to their cause, He is not really related to them.
ON THE PRODUCTION OF LIVING THINGS
From the 'Quæstiones Disputatæ'
According to Augustine, the passage "Let the earth bring forth the green herb" means, not that plants were then actually produced in their proper nature, but that a germinative power was given the earth to produce plants by the work of propagation; so that the earth is then said to have brought forth the green herb and the fruit-yielding tree, inasmuch as it received the power of producing them. This position is strengthened by the authority of Scripture (Gen. ii. 4):--"These are the generations of the heaven and the earth, when they were created, in the day that the Lord God made the heaven and the earth, and every plant in the field before it sprang up in the earth, and every herb in the ground before it grew." From this text we infer, first, that all the works of the six days were created in the day that God made heaven and earth and every plant of the field; and consequently that all plants, which are said to have been created on the third day, were produced at the same time that God created heaven and earth. The second inference is that plants were then produced not actually, but only according to causal virtues, in that the power to produce them was given to the earth. And this is meant when it is said that He produced every plant of the field before it actually arose upon the earth by His dispositive action, and every herb of the earth before it actually grew. Hence, before they came forth in reality, they were made causally in the earth.
This view, moreover, is supported by reason. For in those first days God made the creature either in its cause, or in its origin, or in its actuality, by the work from which He afterward rested; He nevertheless works even till now in the administration of things created by the work of propagation. To this latter process belongs the actual production of plants from the earth, because all that is needed to bring them forth is the energy of the heavenly bodies as their father, so to say, and the power of the earth in place of a mother. Plants, therefore, were produced on the third day, not actually, but causally. After the six days, however, they were actually brought forth, according to their proper species and in their proper nature, by the work of administration.