Theologicae regulae

Upon the necessity of a higher cause follows the necessity of a lower cause; but it is not convertible.

Now that which is necessary according to a higher cause is spoken of in two ways: either that which the higher cause cannot prevent, such as that God be wise, or good: which is so, by the authority of the higher cause, and not by the ministry of the lower cause; or that which the lower cause cannot prevent, as for a virgin to bear a child: for that a virgin, remaining a virgin, should bear a child, was so brought about by the authority of God, that the lower cause could not effectively operate toward this, nor prevent it: she herself, indeed, by the freedom of free will, could prevent herself from bearing a child, but could not prevent it, that, remaining a virgin in mind and body, she should bear. Whence the authority says that the prophecy of predestination must in all ways be fulfilled, that is, it can be prevented by no lower cause. Similarly a thing is said to be necessary in two ways according to a lower cause, either because lower causes operate toward this, as that man be an animal: or because a lower cause cannot prevent that it be, as that the firmament move. Now necessity which occurs according to higher causes is called absolute necessity: that, however, which occurs according to lower causes, is called determinate: according to which the philosophers testify that the determinate follows upon the absolute. Whence if it is necessary that Socrates be moved, it is necessary that he be moved, while he runs: but it is not convertible. With Aristotle, determinate necessity is that which is not proposed simply, but with a determination; as, that Socrates be moved, while he runs. According to a higher cause it is said to be necessary, that the general resurrection of men be about to happen, since it happens by the sole authority of God, nor can any lower cause prevent it. According to this opinion are those who say that it was necessary that Christ have spoken the truth, after he said to Peter: "Before the cock crows, you will deny me three times,"¹ because he had spoken in such a way that it could not be avoided. But this seems to be false, since a lower cause could have prevented it, that it not be true; for Peter could have not denied him. To this it is also objected thus: If Christ said it, it will come to pass: but it is necessary that Christ said it, therefore it is necessary that it come to pass. But this, according to the opinion already touched on, is resolved thus. If something follows from another, and the first is necessary by necessity of nature; but not, if something follows from another, and the first is necessary by necessity of the person, is the last necessary by necessity of nature: but that Christ spoke the truth is necessary as it were for the sake of the term, namely by reason of the person: and such a necessity of person is not followed by a necessity of nature. Again it is objected thus: Something is necessary, and another thing is possible: therefore it can be true along with that. It can be said that it was not necessary that Christ said something, or stated something. Although this statement seems to be about the past, yet it regards the future; just as this statement, that Plato, who will be white, was about to read, is not necessary. Whence it is not necessary either that Socrates spoke the truth, because he said this; for he could have not stated it, that is, said neither the true, nor the false.