Does Theism Foster Scepticism?
I was reading about Plantinga's Argument Against Naturalism, and I've noticed a similar argument among atheist's that holds that theism is also self-refuting. Excuse my rough caricature, but it goes something like this:
If a person believes that an omnipotent being exists, then he is not justified in any belief he may have due to the possibility that this being could be toying with our minds without our knowledge.
I don't really know how to respond to this, and I've never seen it addressed in any published work, so I was just curious to see what you have to say about it.
Brian, this argument has nothing inherently to do with theism or even an omnipotent being. The French philosopher René Descartes in his struggle against scepticism wondered whether there might be an evil demon which is manipulating his thinking to make him believe that he has a body, that there are objects about him, and so on. Contemporary theorists of knowledge who want to appear au courant may conjecture instead about being a brain in a vat of chemicals stimulated with electrodes by some mad scientist or a body lying in the Matrix while inhabiting a virtual reality. Descartes actually tried to escape the evil demon hypothesis by means of the ontological argument for God, who, as a perfectly good being, would not be a deceiver. For Descartes God was part of the solution, not the problem.
Unfortunately, once you start seriously entertaining these evil demon hypotheses there’s no way out of them. Even your argument for God’s existence could be a delusion wrought by the evil demon!
Does that mean that contemporary theorists of knowledge have all embraced scepticism? Not at all! Rather they have come to realize that Descartes’ whole project was wrong-headed. You don’t start from a point of total doubt and try to build your system of beliefs upon indubitable foundations. The lesson of Descartes is that such a project is doomed to failure. Rather many or most of our beliefs are, as Plantinga says, basic beliefs. They are not inferred from more basic beliefs but constitute a person’s foundational beliefs. Beliefs which are appropriately grounded in experience are properly basic. We are perfectly rational to hold such beliefs unless and until we encounter some defeater of those beliefs. We don’t begin from a point of doubt but from what we are confident that we do know.
For example, it seems to me that I have a head. Does anyone really doubt that he has a head? Notice that the mere possibility of error is not enough to defeat this belief. Just because I could be a brain in a vat deceived by a mad scientist doesn’t give me any reason to think that I am. Until you give me some compelling proof that I do not have a body, I am perfectly rational to believe in a properly basic way that I have a head.
Similarly, the theist would need some compelling reason to think that God is deceiving him in order to abandon the belief that he has a head. Brian, turn the tables on the sceptic by asking him to give you a proof that theism gives you a defeater of your properly basic beliefs. About all he can say is, “God could be deceiving you.” But that provides no reason to think that He is. We could be deceived by a mad scientist; but that possibility is not sufficient to defeat our properly basic beliefs. At most, it shows that one cannot prove inferentially that one’s foundational beliefs are true. That’s right; that’s the lesson of Descartes. But that doesn’t imply that our properly basic beliefs are therefore irrational or unwarranted.
The non-theist might reply that the theist is still in a worse position than the non-theist because the theist thinks that an omnipotent God does exist whereas the non-theist does not think that he is a brain in a vat. But the theist will see in God, not a reason to be sceptical of our senses and thinking, but rather the guarantor of the reliability of our belief-forming faculties. By contrast, the non-theist has no such guarantee. This is Plantinga’s point. What does it mean for our beliefs to be warranted, to constitute knowledge? Plantinga’s answer is that these beliefs are formed by cognitive faculties functioning properly in an appropriate environment. What does it mean to function properly? Well, to function as they were designed to. The theist is in a position to explain the proper functioning of our cognitive faculties, whereas the naturalist is at a loss to give an account of this crucial notion. Indeed, for the naturalist, since our cognitive faculties are not selected for truth but for survival, there is no basis at all to think that our faculties are reliable, for there is no probability that beliefs that promote survival will be true.
So Descartes was, in a sense, right in the end. God is not part of the problem but part of the solution to the problem of scepticism.