A Modal Analysis of Free Will
Tuesday, August 31st, 2010The problem of God’s omniscience was incidentally brought up in my metaphysics class and we had a brief discussion about how the arguments might be symbolized in modal logic. This spurred my interest in spelling out the notion of free will in terms of possible worlds.
My first thought was that if I am free, for example, to go to class or not, then the presence of that choice spawns two possible worlds before me (metaphorically, that is, I’m not a modal realist) – one in which I go to class and one in which I don’t. However, this seems insufficient since even objects that we agree have no free will can have possible worlds branching in their future in exactly the same way (i.e., a stone may roll down the hill on one side or the other, so there are two such possible worlds in the stone’s future).
It doesn’t help matters to say that I freely choose to go to class in one possible world and freely choose not to in another, since “freely” is just what I am trying to explain.
My second thought was that freedom must have something to do with one’s power to actualize a possibility. In addition to there being two possible worlds branching ahead of me, if I have free will, it is within my power to actualize one or the other (i.e., to make either one of them the actual world).
In formulating the problem of God’s omniscience we have the following: God is omniscient. God’s omniscience entails that he knows everything, including what will happen in my future in the actual world. So let’s say, for example, God knows that I will go to class today.
On my theory, if I have free will I should be able to actualize the possible world in which I don’t go to class today. But since this would contradict God’s knowledge, I have no such power and therefore no free will. We can conclude that I will go to class today in the actual world as a matter of fact.
One might be inclined to say that there is a possible world in which I stay home, in which God foreknows that I stay home – but it seems no such possible world can exist. The reason is that God’s omniscience requires that there is only one possible world (I’ll expand on this below). Consequently it is trivially true that I will go to class in all possible worlds and so it is a necessary truth in that sense.
When I say my attending class becomes a matter of fact, what I mean is that “Andrew goes to class on August 31st 2010″ is a true statement in the same way that “Andrew was born in March 1982″ is a true statement. If God is omniscient and my view is right, then my future is unchangeable, that is to say determined, in the same way that my past is unchangeable.
To complete the picture, as it turns out, we have to say that everything is determined – everything about the way the world is, was, and will be, may be stated as facts and could not have been (be, or turn out to be) any different. Since God knows every fact about the world, those facts are determined (unchangeable). For example, if God knows that the stone will roll down the left side of the hill, it cannot possibly happen any other way. The only possible world is therefore the actual one.
A weak objection that pops into mind is that one might argue God knows all possibilities and that he knows which possibility I will freely choose to actualize. This response doesn’t get us anywhere since the one he knows I will actualize, in virtue of his knowing it, is the only possible world. Thus the claim that God knows all possibilities just amounts to the claim that God knows what will actually happen.
Things are complicated by the fact that we think God, being all powerful, should be able to create any possible world. Keeping this in mind, the problem of God’s omniscience becomes deeper than it initially appears – it exposes a conceptual inconsistency in the properties traditionally attributed to God. That is, if God knows what he will do, then he cannot do otherwise. If he knows now (in the absolute sense, viz., perfect knowledge) that he will eat pizza for lunch tomorrow, then if he chooses to eat sardines instead he will have contradicted his omniscience. So if he knows he’ll eat pizza, he cannot eat sardines instead. But if he cannot choose to eat the sardines, then he is not all powerful. Either way he doesn’t fit into our traditional conception of God.
P.S. The king of France is bald.
P.P.S. I think asserting that God exists outside of time doesn’t solve the problem, since if that is the only way out of the predicament, it follows that God cannot exist in time, which contradicts his omnipotence. Not to worry though, it’s not anyone’s fault, it’s just that omnipotence is an incoherent concept.