Summa contra Gentiles3.98 Chapter XCVIII. How it is possible, and how it is impossible, for God to do something outside the order of his providence

From what has been said we are able to consider a twofold order: the one, dependent on the first cause of all things, so that it comprises all; the other, a particular order, dependent on a created cause, and comprising such things as are subordinate to that cause. The latter order is manifold, in accordance with the diversity of causes to be found among creatures. Yet one such order is subordinate to another, even as one cause is subordinate to another. Consequently all these particular orders are comprised under that universal order, and are subordinate to that order whereby things are dependent on the first cause. We have an example of this in civil affairs. For there is a certain order among all the members of a household according as they are subject to the head of the house: again the head of the house together with all the other heads of houses in the same city have a certain order among themselves, and in relation to the governor of the city; and he again together with all the other governors in the kingdom is subordinate to the king.

This universal order in respect whereof all things are ordered by divine providence, may be considered in two ways: namely, with regard to things subject to that order, and with regard to the reason of the order, which depends on the principle of the order.

Now we proved in the Second Book that the things themselves which are placed in order by God, proceed from him as from an agent that is not necessitated either by nature or by anything else, but from his simple will, especially as regards the original establishment of things. Consequently God can do certain things besides those which are comprised under the order of divine providence: since his power is not bound to the latter.

On the other hand if we consider the aforesaid order with respect to the reason dependent on the principle, then it is not possible for God to do anything outside that order. Because this order, as we have proved, proceeds from the knowledge and will of God who directs all things to his goodness as their end. Now, it is not possible that God do anything that is not willed by him: since creatures proceed from him, not because it is natural that they should, but because he wills them to, as we have proved. Nor is it possible for anything to be done by him that is not included in his knowledge, since nothing can be willed that is not known. Nor again is it possible for him to do anything as regards creatures, that is not directed to his goodness as its end, since his goodness is the proper object of his will. Likewise, since God is utterly unchangeable, he cannot possibly will that which he willed not before, or begin to know something anew, or direct it to his goodness. Therefore God can do nothing but what is comprised in the order of his providence, even as he cannot do but what is subject to his operation. And yet, if we consider his power absolutely, he can do other things besides those that are subject to his providence or operation: but he cannot do what has not been eternally contained in the order of his providence, because he is unchangeable. Through failing to observe this distinction some have fallen into various errors. Some in an endeavour to extend to things themselves the unchangeableness of the divine order, said that all things must of necessity be as they are; so much so, that some declared that God is unable to do except what he does. Against this we have the words of Matth. xxvi. 53: Cannot I ask my Father, and he will give me presently more than twelve legions of angels?

On the other hand, some, thinking in their carnal wisdom that God, like carnal man, is inconstant of will, ascribed the changeableness of things subject to divine providence, to changeableness in divine providence itself. Against this it is said (Num. xxiii. 19): God is not as a man that he should lie; nor as the son of man that He should he changed.

Others again withdrew contingent things from divine providence. Against these it is said (Lament, iii. 37): Who is he that hath commanded a thing to be done, when the Lord commandeth it not?