Does Knowledge of the Future Rule Out Free Will?
A philosophical investigation
When investigating whether someone, whether human or divine, having perfectly accurate knowledge of future events negates the possibility of free will, we first of all need to define the concepts of free will and its counterpart, determinism. Free will requires a person to have the “ability to have done otherwise” in any given set of circumstances.
Determinism
Determinism, on the other hand, flat out negates people’s ability to choose to do otherwise. In this view a person would always make the same choice in the same situation, as all events are determined by their causes. If I were to go to a restaurant and have to choose between ordering an apple pie or a carrot cake for dessert, determinism claims that in the same set of circumstances at this same point in time, I would always make the same choice and choose, e.g. the apple pie over the carrot cake. If time were rewound, I would make the same choice again, as I would be governed by the preceding causal influences of my past.
Fatalism
Determinism must also be distinguished from fatalism. Fatalism believes that we are destined to make a certain choice no matter how hard we may try to prevent or circumvent it, so whatever happens is unavoidable. Let’s say I go to order ice cream and am undecided between vanilla or chocolate. I eventually choose vanilla but when I leave the shop I notice I was given chocolate instead. I go back in and leave with what looks like vanilla ice cream, but once I try it, it turns out to be white chocolate. So I’m destined to get chocolate, whether I want it or not, and no matter how hard I try to prevent it. And that’s fatalism.
Mind-body materialism
Determinists believe that we are subject to and governed by rigid and predictable laws of the physical world we live in. There are several distinct types of determinism, with a main stream of determinism being based on the argument of materialism. Mind-body materialism, in particular, thinks that human choices are merely a product of brain activity, which in turn is governed by rigid natural laws, leading to human choices being restrained by these laws. As a consequence, it can also be predicted what will happen in the future based on these laws.
Foresight predictability
LaPlace’s demon, a thought experiment proposed by French scholar Pierre-Simon Laplace, claimed that if a figure of superhuman intelligence knew all the forces that govern nature and had unlimited calculating ability, they would be able to accurately predict everything that will happen in the future.
Another argument brought forward in favour of correctly foreseeing future events is the argument of predictability. Proponents of foresight predictability, for example, would argue that future actions can be predicted if we have prior knowledge of the relevant causal factors that precede them.
Where determinism argues that we will always choose according to the stronger of competing motives for actions in our brain, proponents of free will argue that we are able to break free from the rigid chain of motives in our minds and carefully consider the options and even choose a weaker motive. This means at different points in time, we might choose a different option in the same circumstances. In our earlier example, this would mean that today I might choose apple pie, but if time was rewound and I found myself in the same situation again, I might choose the carrot cake.
This brings us to the problem of foreknowledge conflicting with free will. If someone has accurate knowledge of a future event, e.g. that I will switch on my TV at noon today, then it would appear that I cannot refrain from switching it on because otherwise the person’s (or deity’s) knowledge would be incorrect and thus not accurate.
So if there is an omniscient person or deity, this would seem to take away my ability to do anything other than what I am actually doing. Having the ability to choose to perform a particular action or not would therefore be incompatible with someone’s foreknowledge of future events. This conclusion is countered by truth-supervenience, promoted for example by the philosopher and theologian Luis de Molina, which stipulates that truth depends on events rather than events on truth, as foreknowledge of the truth does not create the truth.
Truth depends on events rather than events on truth.
Some folks believe that foreknowledge does not cause future results and therefore free will is in no way tied to foreknowledge. This means I am free to choose to switch on my TV at noon and as a result of this free act, the omniscient entity will know from all eternity that I will do so. Free will is therefore compatible with omniscience and foreknowledge of future events. As McCall* puts it, “an event Q happening is true because Q happens, rather than the event happening because the proposition is true.” This is what we call the incompatibility argument.
The incompatibility argument is countered by fans of the dependence response, which claims that the incompatibility argument has a false premise. Specifically, that if someone is able to perform an action in the absence of foreknowledge, then they are also able to perform the same action in the presence of foreknowledge. In other words:
Bringing foreknowledge into the mix is not enough to rule out free will.
So if I had refrained from switching on my TV at noon today, I could have done so with or without an entity having foreknowledge of this act, and I could have made the entity have a different correct past belief by making a different choice. The foreknowledge therefore depends on my choice.
If I had made a different choice today, the entity would have never had the foreknowledge that I would switch on my TV at noon today but would have had the opposite foreknowledge that I would not switch it on. Let’s bear in mind though that the dependence response does not claim that we have the freedom to do otherwise, but instead it states that if we could have done otherwise without an entity’s foreknowledge, then simply adding such foreknowledge to the mix does not undermine our freedom to make a different choice.
Future contingents
In fact, some philosophers go as far as claiming an entity’s accurate prior foreknowledge of future events is contingent upon the facts that will happen rather than the other way round. And also that the choice we make in the future determines whether or not the preceding foreknowledge was accurate.
This corresponds to Aristotle’s famous sea battle example. Here, the truth value of a claim stating that there will be a sea battle tomorrow cannot be determined today because today it cannot be established for certain at this point in time whether the sea battle is actually going to take place tomorrow or not. Instead, this proposition about the contingent future will become true only if the event occurs, or false if the event does not occur.
Aristotle clearly rejected the notion that statements in the future tense and either true or false at the point in time when they are being uttered. So we can say:
Possibly being wrong does not undermine the possibility of an entity knowing the future.
There are even claims that an entity’s foreknowledge in the past is merely an accidental necessity, compatible with metaphysical and logical contingency.
Theistic vs. secular views
A further important distinction is that between the theistic and secular views on the problem of compatibility of free will and an entity’s omniscience. Historically, God has been viewed as an omniscient entity in religious contexts. From a theistic perspective, a possible solution to this problem dating back to Plato is the stipulation of the concept of timelessness whereby God exists outside time and thus has atemporal omniscience. This does not mean that God merely looks into the future but has perfectly accurate and constant knowledge of the past, present and future. This means we make free choices and God has a privileged position outside of time that enables him to view all of our actions and choices instantaneously.
But the problem with this thesis is that we cannot meaningfully talk of an entity having any cognitive state outside of time because we simply cannot conceive what a conscious experience outside of time would be like. So the timelessness solution cannot be coherently expressed and therefore fails to solve the problem of free will and an entity’s foreknowledge of future events. It also fails to resolve the secular approach to the problem of incompatibility of foreknowledge and free will.
The problem with epistemic determinism
The secular counterpart to the theistic approach is epistemic determinism, which refers to any entity at all (that is not God) having any sort of foreknowledge of future events and postulates that if such an entity has advance knowledge of a future action, then this action must occur and cannot be prevented, making free will an illusion. The truth of a statement is considered a prerequisite of such knowledge of the future. But it has been argued that epistemic determinism is subject to a modal fallacy error. Epistemic determinism presupposes that it is impossible for an entity to know that a certain event will happen and for this event not to happen. We could say that:
- A. An entity knows that a person will make choice X and that the person believes this to be a freely made choice.
- B. It is now necessary that X happens.
- C. If it is now necessary that X happens, then X cannot be otherwise and there are no genuine choices for the person to make.
- D. If the person cannot make other choices and act otherwise, then they do not act freely.
- E. Therefore, when a person performs an act, they do not do so freely.
These arguments seem to commit a modal fallacy though. They assume that if event X is true, it becomes necessary for X to be true, but this is incorrect because X remains contingent and therefore possible rather than necessary. Once this logical error is removed, the argument for epistemic determinism collapses because even if an event is known in advance, this does not make it necessary. Rather, it remains contingent and can potentially always become either true or false.
So what does it all mean?
To sum up, the argument that truth depends on events rather than events on truth, because foreknowledge of the truth does not create the truth as such seems convincing. Knowledge of future events remains contingent, and whether or not past knowledge of a future event is accurate or not depends entirely on whether the predicted event actually takes place or not rather than the other way round. A person or deity having perfectly accurate knowledge of future events does therefore not negate the possibility of free will.
* McCall, S. (2011), ‘The supervenience of truth: freewill and omniscience’, Analysis 71(3), pp. 501–506.
