MT103-P03. PREV - NEXT - THIS - UPPER - TOPThere are two ways in which a thing may be said to be necessary or impossible, viz., in respect to its essence or its cause. In respect to His essence we know that God necessarily exists. For His essence cannot be conceived without existence. From the implicated essence of chimeras they cannot exist. In respect to their cause, things, i.e., materials, are either impossible or necessary. For if we merely regard their essence, it is possible to clearly conceive of that without their existence. Therefore, they cannot exist by the power and necessity of their own essence but only by the power of their cause, viz., God the creator of all things. If, thus, it is the divine decree that something should exist, it exists from necessity, or if less than this, it will be impossible for it to exist. For it is a self-evident fact that that which has no cause, internal or external, for its existence, cannot possibly exist. And an object under this hypothesis is so conceived that it cannot exist by the power of its own essence, by which I mean an internal cause, nor by the divine decree, the one external cause of all things. Whence it follows that objects under such condition cannot exist at all.
In how many ways a thing may be said to be necessary or impossible.
MT103-P05. PREV - NEXT - THIS - UPPER - TOP2. We must remember that not only does the existence of all created things depend upon God's decree, but their essence and nature as well. This will be clearly shown in Part 2. below. Whence it follows that created objects have no necessity in themselves, for their essence is not self derived. No more do they exist by their own power.
Created objects derive their essence and existence from God.
MT103-P06. PREV - NEXT - THIS - UPPER - TOP3. Finally, it should be noted that the necessity of created objects, such as we find there from the power of the cause, is either in respect to their essence or to their extension. These two must be distinguished in created objects. The one depends upon the eternal laws of nature, the other upon the series and the order of its causes. In God whose essence and existence are the same, necessity of essence is equivalent to necessity of existence. Whence it follows that if we conceive of the whole order of Nature we will find that many things cannot exist whose nature we conceive clearly and distinctly, that is, whose nature is such of necessity. For we find that it is equally impossible for such things to be, as for example we know that it is impossible for a great elephant to pass through the eye of a needle. Nevertheless the nature of each is clearly conceived.
The necessity in created objects is derived from their cause, and relates to their essence or existence. In God these two things are not to be distinguished.
Therefore things of this nature do not exist except chimeras,
which we are able neither to imagine nor to understand.
MT103-P09. PREV - NEXT - THIS - UPPER - TOPIf any one chooses to deny this his error may be pointed out with little trouble. For if he will consider Nature and how it all depends upon God, he will find nothing contingent. That is, he will find nothing, which, from a part of the object is able to exist and not exist, or, as it is generally expressed, the contingent is the real. This is evident, also, from what was said in Ax. 10, Pt. 1. namely, that no more power was needed to create the world than to conserve it. Therefore no created object does anything by its own power for the same reason that it did not begin to exist by its own power. From which it follows that nothing has been created except by the power of the Cause which has created all things, namely, the power of God, who by His concurrence procreates everything every single moment. And since nothing exists except by divine power alone, it is easily seen that the world as produced by God's decree is such as he wished it to be. So, too, since there is no change or inconstancy in God (per Prop. 18 and Coroll. Prop. 20, Pt. 1.), those things which He now produces, He has decreed from eternity that they should be produced. Then since nothing more is needed for their existence than God's decree that they should exist, it follows that the necessity of the existence of all created things has existed from eternity. Nor can we say that these things are contingent since God might have decreed otherwise. For since in eternity there are no effects of time neither a future nor a past, it follows that God did not exist before that decree, so that he was able to decree something else.
Possible and contingent only signify defects in our understanding.