Aristotle is widely regarded as one of the greatest philosophers of all time. He is perhaps most highly regarded by Catholics because of the influence his ideas came to have in Medieval Christendom. Figures from Thomas Aquinas to William of Ockham referred to him as “the Philosopher”. Nevertheless, as widely regarded as Aristotle was, he was not seen to be infallible and the medievals would disagree with him from time to time when his ideas directly contradicted the faith. One view of Aristotle that would at least seem to contradict the faith is his view that some future contingent propositions lack a truth value. At the very least this position complicates the issue of divine foreknowledge for it seems to deny the very possibility of such knowledge. In this essay, I will argue that even if not all the medievals did disavow this error of Aristotle, they should have. I will briefly examine Aristotle’s view, explain why he is and must be wrong and then look at a couple of Christian responses to his view and show why the view of Luis Molina is most insightful.

Aristotle’s View

Aristotle, in chapter 9 of a fairly short work On Interpretation he argues that there are no truths about future contingent events. If there were, he argues, the future events would not be contingent but necessary. Aristotle claims that a present tense truth like “Tomorrow I will go to work.”, if true, necessitates that I will go to work tomorrow. Thus, I am not free not to go to work tomorrow if it is true today that “I will go to work tomorrow”. His argument can be put into the following syllogism:

1. If a proposition is true, then reality necessarily corresponds to that proposition.
2. There are some contingent things in the future.
3. Therefore, some propositions about future contingent things are neither true nor false.

Aristotle’s version of premise one goes as follows:

Thus, if it is true to say that a thing is white, it must necessarily be white; if the reverse proposition is true, it will of necessity not be white.

On Interpretation Chapter 9

If he is correct, then it seems that if some statement about the future is true, it necessitates the future.

Wherefore, if through all time the nature of things was so constituted that a prediction about an event was true, then through all time it was necessary that that should find fulfillment; and with regard to all events, circumstances have always been such that their occurrence is a matter of necessity. For that of which someone has said truly that it will be, cannot fail to take place; and of that which takes place, it was always true to say that it would be.

On Interpretation Chapter 9

This is why Aristotle concludes

One [future contingent] may indeed be more likely to be true than the other, but it cannot be either actually true or actually false. It is therefore plain that it is not necessary that of an affirmation and a denial one should be true and the other false.

On Interpretation Chapter 9

According to Aristotle, the truth of a thing imposes a kind of necessity on reality, whether or not humans or anyone for that matter speak or know such truth. This is where Aristotle goes wrong.

Aristotle, as far as I can tell reverses the relationship between truth and reality. He is correct in believing that truth and reality necessarily correspond for truth just is the correspondence with reality. That does not mean however that truth determines reality. Rather, truth is such because of reality. The truth that the banana next to me is yellow does not make the banana yellow. Rather, the banana’s being yellow is what makes it true that the banana is yellow. Similarly, if it is true that tomorrow I will eat the banana, then it is my future eating of the banana which makes that statement true, not the truth about my eating that somehow makes me eat the banana.

Why Aristotle Must Be Wrong

Aristotle’s argument, if true, presents problems for orthodox Christians who believe in Scripture and more specifically prophecy. Prophecy about future events is present throughout Scripture and is incompatible with Aristotle’s claim that propositions about future contingent events lack a truth value. Let us take Jesus’ prophecy about Peter’s denial as an example.

Clearly, the prophecy was about a contingent event, indeed one that involved Peter’s free choice to reject association with Christ. Since all Catholics hold this act to be a sin, it must have been done freely and was thus contingent and not necessary. According to Aristotle, Jesus’ statement “Truly, I tell you, this very night, before the rooster crows twice, you will deny me three times” (Mark 14:30 ESV) wasn’t in fact true. So much for “Truly, I tell you”! Obviously, this was a true statement that was known and spoken prior to the contingent event about which it spoke coming true. Thus, if we are to be faithful to the Word of God, we must jettison Aristotle’s erroneous view that future contingents cannot have a truth value.

How Scholastics Dealt with this Issue

Aristotle’s view presented issues for medievals in their explication of divine foreknowledge. If Aristotle is right then statements about future contingent events cannot be true. If they aren’t true how does God know them? Or alternatively, if God does know them and they are true, does that necessitate future events meaning no future choices are truly free?

Some thinkers like William of Ockham in his Ordinatio recognize that Aristotle’s view conflicts with Orthodox teaching and simply leaves it up to mystery how God knows the future:

[I]t is to be held without any doubt that God knows all future contingent facts evidently and with certainty. But to explain this evidently and to express the manner in which He knows all future contingent facts, is impossible for any intellect in this life. And I say that the Philosopher would maintain that God does not know all future contingent facts evidently and with certitude, and he would maintain this for the following reason…Notwithstanding this argument, it has to be held that God evidently knows all future contingent facts. The manner in which he knows them, I however, do not know.

Philosophical Writings pg. 133

This passage exemplifies the deference Aristotle received from many of the Medievals. Even though Ockham knows his teaching to be false, he struggles to know exactly why and simply leaves it up to mystery.

Other thinkers like Thomas Aquinas think they can reconcile Aristotle’s position with divine foreknowledge by appeal to divine timelessness.

Aquinas agrees with Aristotle on his commentary on On Interpretation:

The reason for this consequence is evident, for these two cannot stand together: that something truly be said to be, and that it not be. For this is included in the signification of the true: that which is said, is. If, therefore, that which is said concerning the present or the future is posited to be true, it is not possible that this not be in the present or future (emphasis mine)

Commentary on On Interpretation Lecture 13

Here it seems Aquinas makes the same error as Aristotle when he says “If that which is said concerning…the future is posited to be true, it is not possible that this not be in the…future.” This is, with all due respect to the Angelic Doctor, in my view, false. The fact that a statement about the future is true implies only that the future event will happen not that it must happen. Aquinas seems to think that truth imposes a kind of necessity on the future (and the present) which is to reverse the relationship between reality and truth.

Aquinas deals with the problem of divine foreknowledge in this same text as well as in the Summa by appealing to divine timelessness. Aquinas in both the Summa and his commentary appeals to an analogy of a person standing away from and above a caravan of people to explain how God sees all events in time at once.

God, however, is wholly outside the order of time, stationed as though at the summit of eternity, which is wholly simultaneous, and to him the whole course of time is subjected in one simple intuition. For this reason, he sees in one glance everything that is effected in the evolution of time, and each thing as it is in itself, and it is not future to him in relation to his view as it is in the order of its causes alone (although he also sees the very order of the causes). But he sees each of the things that are in whatever time completely and eternally, as the human eye sees Socrates sitting, not in its causes, but in itself.

Commentary on On Interpretation Lecture 14

On this analogy, God’s knowledge of the future seems to be based upon observation of the future. Whether that was Aquinas’ real position is a matter of much dispute. In any case, the view that God’s knowledge of the future comes from this view in eternity is problematic for a number of reasons which we don’t have the space to explore here. Most significantly, it fails to account for all future contingent truths and it undermines divine sovereignty. These problems would cause Thomists from the 16th century onward to favor a different view/reading of Aquinas.

Up to this point then we have seen two of the most prominent medieval thinkers fail to adequately handle the issue of divine foreknowledge in light of Aristotle’s argument against the truth of future contingents. While both Ockham and Aquinas (at least the interpretation of him presented above) hold firm to the orthodox view that God knows the future, both of them take for granted Aristotle’s argument. Both, in my view, fail to then adequately explain God’s foreknowledge. Ockham leaves it up to mystery, and Aquinas offers an explanation that even his later defenders would reject. It would not be until the 16th century that a young Jesuit theologian named Luis de Molina would come along to offer a better alternative.

Molina’s Solution

Luis de Molina (1535-1600) was a Spanish Jesuit who came of age during the years of the Council of Trent. Molina’s goal in life was to defend Catholic doctrine against the attacks of the various Protestant denominations that had cropped up by this time particularly those of the Lutheran and Reformed traditions. Molina’s most famous work, his Concordia attempts to reconcile among other things, God’s foreknowledge, providence, and human free will. How does Molina reconcile foreknowledge and free will?

First, he will disagree with Aristotle and believes that future contingent propositions are in fact true. He distinguishes between propositions being determinatively true, that is whatever is going to happen cannot be prevented and indeterminately true. While he agrees with Aristotle that a future contingent cannot be determinatively true, Molina thinks it can still be true. As an aside, Aquinas too uses the qualification of “determinatively true” in his commentary on Aristotle’s argument but it is unclear what level of truth future contingents still have if any.

Molina responds to an objection to divine foreknowledge based on Aristotle’s argument by correctly noting the proper relationship between the truth of a future thing and our and God’s knowledge of it. Molina firstly points out that even if it is true that what God knows he knows necessarily, this does not mean that if God knows “Peter will deny Christ at time t”, that this happens necessarily. Rather,

[T]he major premise [God knows all things necessarily] should be conceded if it has to do with the necessity of the consequence, since the following consequence is necessary: ‘God knows that this or that is going to be: therefore, it is going to be.’

On Divine Foreknowledge pg. 190

The necessity of consequence is to be distinguished from necessity of consequent which would imply in this case that the thing God foreknows is going to be necessarily. Molina then avoids the subtle mistake made by Aristotle and Aquinas earlier by not projecting necessity onto the consequent.

Secondly, Molina follows Aquinas and believes that God’s knowledge of things, unlike ours, is not limited by the contingency or necessity of the thing. Where he differs from Aquinas is his account of how God knows such things. Rather than appealing to the analogy of the road like Aquinas, Molina appeals to what he calls middle knowledge.

Middle knowledge is so called because it lies in between two types of knowledge that were attributed to God in Molina’s time: 1) what Molina calls natural knowledge, or God’s knowledge of all necessary truth, and 2) God’s free knowledge, his knowledge of the contingent world which he wills to create. Like natural knowledge, middle knowledge is pre-volitional, that is, it is logically prior to God’s will to create. However, middle knowledge is contingent like free knowledge. The content of middle knowledge are various conditional statements, today called counterfactuals, about what free creatures would do were they placed in this or that circumstance. Some of these circumstances do come to pass but many are mere possibilities never actualized by God. Since God knows, prior to creation, what creatures would do in various circumstances, once he places them in those circumstances, his knowledge of what they will do follows easily. Obviously, much more could be said about Middle knowledge but this suffices for our purposes.

Conclusion

As we have seen, the issue of the truth of future contingents and especially the relation of this to divine foreknowledge is a difficult issue. Aristotle, from whom the bulk of the Catholic scholastic tradition drew heavily, argued that future contingent statements lacked a truth value since having one would obliterate the contingency of the things themselves. His argument was highly influential and the likes of Aquinas and William of Ockham seem to agree with it even while it posed problems for divine foreknowledge. Luis Molina, a Catholic reformer, took a novel approach and rejected the full extent of Aristotle’s argument. Molina used the concept of Middle knowledge to explain how God’s foreknowledge flows entirely from his will and pre-volitional knowledge and how this knowledge is compatible with genuine contingency, most importantly human free choice. One lesson which the issue of future contingents and divine foreknowledge shows is that even the most brilliant minds like Aristotle can sometimes make subtle which have wide influence for centuries. It is important then to always take a critical philosophical approach even to those figures whom we revere and whose teachings we preserve.

Sources Cited

Aquinas, Thomas. Commentary on Aristotle’s On Interpretation https://aquinas.cc/la/en/~Peri.Bk1.L13

Aristotle’s On Interpretation: http://classics.mit.edu/Aristotle/interpretation.1.1.html

Molina, Luis De. On Divine Foreknowledge: Part IV of the Concordia. Translated by Alfred J Freddoso. Ithaca: Cornell University Press, 1988

Ockham, William. Philosophical Writings. Edited and Translated by Philotheus Boehner, O.F.M. Indianapolis: Hackett, 1990