An Argument Against the Principle of Sufficient Reason

(The following is loosely based on an argument of Peter van Inwagen’s. See his book Metaphysics (Westview Press) pp. 104-107 or his book An Essay on Free Will (Oxford) pp. 202-204.)
 According to William Rowe, the Principle of Sufficient Reason (hereafter ‘PSR) says two things: PSRa: There is an explanation for the existence of every being.

PSRb: There is an explanation for every positive fact.

 Rowe distinguishes the notion of a dependent being from that of a self-existent being. Recall that a dependent being is a being whose existence is explained by the causal activity of others. A self-existent being is a being whose existence is explained by its own nature or essence. Now with the introduction of PSRb, we have the need for another, related distinction. Some facts are contingent—they are facts but they might not have been. Some contingent facts are brute facts—these are contingent facts for which there is just no explanation. An explained contingent fact is a contingent fact that is explained by another fact.

But what kind of explanation are we talking about here? Obviously, the explanation must be true (although it need not be known or even knowable by humans). What else can be said about the explanations posited in the PSR? Well, we get a hint of the fuller understanding by the name of the principle: the principle of sufficient reason implies that the explanation must be sufficient.

Suppose we want an explanation of how a particular burglary was pulled off. Suppose the answer we get is this: the burglary occurred in a high crime neighborhood and the home didn’t include a deadbolt on any of the exterior doors or bars on any of the windows, and 64% of such homes in such neighborhoods get burglarized in any given five-year period.

Would this be a sufficient explanation for the burglary in question? No. It is, perhaps, a sufficient explanation of why it is likely that this house will be burglarized in any 5-year period, but it is at best a very impartial explanation of this particular burglary.

A sufficient explanation is an explanation that provides a sufficient condition for the fact it explains. In other words, a sufficient explanation is sufficient to rule out other possibilities given that the condition holds.

So a sufficient explanation of this burglary would include the name of the person who broke in, how she got in, exactly what she took, etc.

Another example: a car won’t start and the explanation is that cars this starters this old often don’t start. That’s an incomplete explanation. A sufficient explanation for the car’s not starting will spell out conditions that are sufficient for this car’s not starting at this time.

Now the believer in the PSR says that there must be a sufficient reason for every fact. Loosely, she says that God stops a regress of reasons because God requires nothing else to explain his existence; God’s nature is a sufficient explanation of God’s existence. But a dilemma can be created here.
 
 

If the PSR is true, can God be free with regard to creating at all?

Suppose God is significantly free regarding creation. Then God could have not created and the fact that God creates is contingent. If that is right, then the fact that God exists is not a sufficient reason (explanation) for the fact that God creates, since necessarily, if there are A worlds that are B worlds and A worlds that are not-B worlds, then A isn’t a sufficient reason for B. So if God freely creates then the bare fact that God exists isn’t a sufficient reason for a world of dependent beings.

But, you say, what about "God intends to create" as a sufficient explanation? Given that God is self-existent and omnipotent and all the rest, if God intends to create, then God creates (nothing can thwart God’s plans); so the fact that God intends to create gives us a sufficient explanation of God’s creating. Very good. For "God intends to create" does seem to give us a sufficient explanation for "God creates" since the former is sufficient for the latter. There is just one problem: if God is free, then the fact that God intends to create doesn’t seem to stop the regress because this fact, though sufficient for God’s creating, is not itself necessary; so it is itself in need of explanation. So if God is free, it looks as though there is no sufficient reason for the world of dependent beings. The answer to our question would seem to be ‘no.’
 
 

If the PSR is true, can God freely choose to create one world rather than another?

So, you say, suppose we figure that God isn’t free and that he creates of necessity? What is the problem with that? Well, first and perhaps least, this isn’t the traditional view. So the theist who goes this route changes her view. But things get worse.

Remember Rowe’s earlier paper on freedom. He distinguishes two questions: is God free to create at all? and if God creates, is he free as to what to create? We are now supposing that the answer to the first question is ‘no.’

Now maybe we want to try to preserve some divine freedom so we claim that although the fact that God creates is necessary, God has some choice about which world he creates. For simplicity’s sake, let’s suppose God is free to choose between only worlds A and B. Suppose God opts for A.

Now "God intends to create" is necessary (on our current assumption) and it explains "God creates." Very good. But to do the trick, it must also be a sufficient explanation for the fact that God creates world A. But it’s not because on our current assumptions God could have created world B. Then the fact that God intends to create sometimes leads to God’s creating B (and not A) worlds. Then his intention to create isn’t a sufficient reason for his creating the A world. So PSR is violated. But since we are assuming PSR, we must conclude that God is free neither with regarding to creating at all nor with regard to creating world A rather than world B.
 
 

If the PSR is true, then is every fact necessary?

Okay, then, fine, you say. God is not free with respect to creating and he has to create world A. Still, on these assumptions we have a sufficient explanation of the existence of dependent beings, right?

Yes, but we are now saddled with the following unhappy consequence: although humans might be dependent beings in our current sense, they are none the less necessary. For if we are saying that it is necessary both that God creates at all and that God creates precisely the world he does, then we are saying that there are no worlds at which God exists and we don’t. But the traditional view says God exists at every world; and indeed, this seems to be part of the idea of self-existence. But then if God exists necessarily and God necessarily creates us, then we exist necessarily too. That means that we couldn’t have not existed. Furthermore, since every fact about us also has a sufficient reason and is part of what makes this the A world, then every fact about us is essential to us. We couldn’t have been any different than we are. This is a hard pill to swallow and a bitter consequence of the most straightforward reading of the PSR.
 

One final, quick argument:
Suppose we list every contingent fact. Suppose we now tie them all together with ‘and’s. In other words, suppose there are just two contingent facts, fact F and fact G. Then we could write down their corresponding propositions and put an ‘and’ between them so that we’d now have a conjunctive proposition ‘F and G.’ Suppose that we do that with not just two facts, but with all the contingent facts. Call the mammoth conjunction ‘C.’ Now if the PSR is true, then there is some sufficient explanation for C. This explanation must be either necessary or contingent. If it is contingent, then it is part of C. But no contingent proposition could be the explanation for a proposition of which it is a conjunct (because then it would be explaining its own existence and if it could do that it would be necessary and not contingent). On the other hand, if the explanation of C is itself necessary and if it is a sufficient explanation of C, then C will be necessary (since C will be a necessary consequence of a necessary proposition). So either C is unexplained or it is necessary. But the PSR tells us that it can’t be that C is unexplained so it must be necessary. So PSR entails that all facts are necessary. As a professor of mine in graduate school, Stephen Schiffer, would say, "Believe it if you can."