Foreknowledge does not cause what it foresees

After this let us see how he puts it. “He foretold these things,” he says, “being a god, and what was foretold certainly had to happen. So a god brought his own disciples and prophets, with whom he dined and drank, to the point of becoming impious and unholy, when he above all ought to have done good to all men, and especially to those who shared his table. Or would one who had shared a man’s table not afterwards plot against him, while one who had feasted with a god became his plotter? And, what is still more absurd, the god himself plotted against those at table with him, by making them traitors and impious men.”

Since you wish me to answer even those arguments of Celsus that seem to me trivial, we shall say this in reply. Celsus thinks that what is prophesied by some kind of foreknowledge comes to pass because it was prophesied. We do not grant this. We say that the one who prophesied is not the cause of what will be on the ground that he foretold it would happen; rather, what will be, which would have been even if it had not been prophesied, gave the one who foreknew it the cause for foretelling it. And all of this lies within the foreknowledge of the one who prophesies it: when it is possible for a given thing to happen and possible also for it not to happen, one particular one of the two will come about. And we do not say that the one who foreknows takes away the possibility of its happening or not happening and says, as it were, something like this: “This will certainly be, and it cannot turn out otherwise.” This principle extends to all foreknowledge of anything that lies in our power, whether in the divine Scriptures or in the histories of the Greeks. And what the logicians call the “lazy argument”, which is a sophism, will not be a sophism as far as Celsus is concerned; but by sound reasoning it is a sophism.

To make this understood, I shall use from Scripture the prophecies about Judas, or our Saviour’s foreknowledge of him as the one who would betray him; and from the Greek histories, the oracle given to Laius, granting for the present that it is true, since that does not harm the argument. Concerning Judas, then, the hundred and eighth Psalm (Psalm 109 in English Bibles) speaks in the person of the Saviour; it begins: “O God, do not pass over my praise in silence; for the mouth of a sinner and the mouth of a deceitful man have been opened against me” (Psalm 109:1–2). If you observe what is written in the psalm, you will find that, just as he was foreknown as the one who would betray the Saviour, so he was also the cause of the betrayal, and because of his wickedness deserved the curses spoken in the prophecy. For let him suffer these things, it says, “because he did not remember to show mercy, and persecuted a poor and needy man” (Psalm 109:16). So he could have remembered “to show mercy” and not persecuted the one whom he persecuted; but though he could, he did not do so, and betrayed him instead, so that he deserves the curses pronounced against him in the prophecy.

Against the Greeks we shall use what was said in this way to Laius, whether the tragic poet set it down in its very words or in words of equal force. It is said to him, then, by the one who indeed foreknew what would be: “Do not sow the furrow of children against the will of the gods; for if you beget a child, the one born of you will kill you, and all your house will walk through blood” (Euripides, Phoenician Women 18–20). In this too, then, it is clearly shown that it was possible for Laius not to sow “the furrow of children”, for the oracle would not have commanded him what was not possible; and it was also possible for him to sow, and neither of the two was forced upon him. But because he did not take care not to sow “the furrow of children”, it followed from his having sown that he suffered the tragedy of Oedipus and Jocasta and their sons.

The so-called lazy argument too, which is a sophism, is of this sort: it is put hypothetically to a sick man and, as a sophism, dissuades him from using a physician to regain his health. The argument runs like this: “If it is fated for you to recover from the illness, you will recover whether you call in the physician or not. But if it is fated for you not to recover from the illness, you will not recover whether you call in the physician or not. Now either it is fated for you to recover from the illness or it is fated for you not to recover. Therefore you call in the physician in vain.” But against this argument something like the following is wittily set: “If it is fated for you to beget children, you will beget children whether you lie with a woman or not. But if it is fated for you not to beget children, you will not beget children whether you lie with a woman or not. Now either it is fated for you to beget children or not to beget them. Therefore you lie with a woman in vain.” For just as in this case, since it is out of the question, indeed impossible, that a man who has not lain with a woman should beget children, lying with a woman is not resorted to in vain, so, if recovery from illness comes by way of medicine, the physician is necessarily called in, and it is false that “you call in the physician in vain.”

We have brought in all this because of what the most wise Celsus set down when he said: “Being a god, he foretold, and what was foretold certainly had to happen.” If by “certainly” he means “under compulsion”, we shall not grant it to him, for it was possible for it not to happen as well. But if he says “certainly” in the sense of “it will be”, which nothing prevents from being true even though it is possible for it not to happen, this does no harm to the argument. For it did not follow from Jesus’ having truly foretold what concerned the traitor, or what concerned the one who denied him, that he himself became the cause of their impiety and unholy deed. He who, as we hold, knew “what was in man” (John 2:25) saw the traitor’s wicked character, and saw what he would dare because he loved money and did not hold firmly to what he ought to think about his teacher; and so, among many other things, he said this too: “He who has dipped his hand with me in the dish, he will betray me” (Matthew 26:23).