A lot of people seem to want me to take a swing at Exbeliever's response to my argument from reason. I should begin by saying that I didn't invent the argument. It was most famously defended by a Christian apologist that Exbeliever can be perhaps be excused for never having heard of, C. S. Lewis. A version of the argument can be found in the book Scaling the Secular City by another obscure apologist by the name of J. P. Moreland. And there's a really obscure philosopher from the University of Notre Dame who has developed what is known as the Evolutionary Argument Against Naturalism, which bears a family resemblance to the arguments from reason that I defend. His name is Alvin Plantinga.
In general, the argument makes a distinction between naturalistic world-view, in which the fundamental entities of the universe lack mental characteristics (atoms, or maybe something else, but not something that at all resembles a mind), and world-views such as theism, but also pantheism and absolute idealism, according to which the fundamental causes of the universes are mental, or as Lewis would say, more like a mind than anything else. The argument from reason, if successful, gives us a good reason to suppose that one of the mentalistic world-views must be true and that naturalism is false. It is designed to enhance the likelihood that theism is true by eliminating some alternatives, alternatives that are in fact the most popular non-theistic world-views.
It's a good idea to look at what happened in Lewis's own case to see how the argument contributed to his coming to belief in God. Lewis had been what was then called a "realist", accepting the world of sense experiece and science as rock-bottom reality. Largely through conversations with Owen Barfield, he became convinced that this world-view was inconsistent with the claims we make on behalf of our own reasoning processes. In response to this, however, Lewis became not a theist but an absolute idealist. It was only later that Lewis rejected absolute idealism in favor of theism, and only after that that he became a Christian. He describes his discussions with Barfield as follows:(He) convinced me that the positions we had hitherto held left no room for any satisfactory theory of knowledge. We had been, in the technical sense of the term, “realists”; that is, we accepted as rock-bottom reality the universe revealed to the senses. But at the same time, we continued to make for certain phenomena claims that went with a theistic or idealistic view. We maintained that abstract thought (if obedient to logical rules) gave indisputable truth, that our moral judgment was “valid” and our aesthetic experience was not just pleasing but “valuable.” The view was, I think, common at the time; it runs though Bridges’ Testament of Beauty and Lord Russell’s “Worship of a Free Man.” Barfield convinced me that it was inconsistent. If thought were merely a subjective event, these claims for it would have to be abandoned. If we kept (as rock-bottom reality) the universe of the sense, aided by instruments co-ordinated to form “science” then one would have to go further and accept a Behaviorist view of logic, ethics and aesthetics. But such a view was, and is, unbelievable to me.
C. S. Lewis, Surprised by Joy (San Diego, Harcourt Brace, 1955), 208.
So did the argument he accepted make theism more likely? It certainly did. In his mind it gave him a reason to reject his previously-held naturalism. Now you might think of Absolute Idealism an atheistic world view; I don't think you would want to call pantheism atheistic, but the argument runs a reductio absurdum against non-mentalistic world-views.
Consider the following argument:
1. Either the fundamental causes of the universes are more like a mind than anything else, or they are not.
2. If they are not, then we cannot make sense of the existence of reason.
3. All things being equal, world-views that cannot make sense of the existence of reason are to be rejected in favor of world-views that can make sense of the existence of reason.
4. Therefore, we have a good reason to reject all worldviews reject the claim that the fundamental causes of the universe are more like a mind than anything else.
Now if you want to hold out the idea that a idealist world-view is nevertheless atheistic, then my argument merely servces to eliminate one of the atheistic options. But suppose someone originally thinks that the likelihoods are as follows.
Naturalism 50% likely to be true.
Idealism 25% likely to be true.
Theism 25% likely to be true.
And suppose that someone accepts a version of the argument from reason, and as a result naturalism drops 30 percentage points. Then those points have to be divided amongst theism and idealism. So the status of theism is enhanced by the argument from reason.
Exbeliever writes:Notice that the skeptic is simply to assume that something like a god can exist and after assuming this, it can be posited as an explanation of a phenomenon like reason. Much like presuppositionalism and its TAG argument, Reppert demands that the skeptic presuppose the most controversial aspect of his worldview (i.e. the existence of a non-corporal being who reasons without a physical brain) and then accept this presupposition as a valid "solution" to a "problem" of epistemology.
Now we have to tease out what he means by can. If "can" means logically possible, then all I need to show that is that there is no contradiction in the assertion "God exists." And I think that's pretty clear. If on the other hand, he means "it is plausible that God exists," well, the plausibility of a belief differs from person to person. There is no person-independent way of assessing antecedent probabilities, at least as I see it. So yes, if someone thinks that the existence of God is hopelessly implausible, he might conclude either that there must be some naturalistic understanding of the phenomenon of reason that has not yet been discovered, or he can conclude that some non-theistic mentalistic world-view must be true. But that does not alter the fact that the argument provides a substantial reason for believing in God. I have never said that the argument is absolutely decisive, in fact I have disappointed some supports of the argument with the modesty with which I present my arguments.
In EXB's discussion of the explanations for computer malfunctions, it seems we have a reason for preferring computer sprites to infallible designers. If these really are the only options, then evilcomputerspiritism must be accepted. It's just that we all know perfectly well that there are more alternatives, and the most plausible explanations are not on the table. So the argument is a false dilemma. In the case of my argument, where are the "third alternatives" other than what I have identified, namely, pantheism and idealism?
EXB writes: What Reppert has done in his argument is hidden the fact that the idea of a god, itself, must be plausible if it is to be called on as a "solution" to an epistemological "problem." To solve an extraordinary problem, he has posited an even more extraordinary solution. Simply having any old "solution" does not make a worldview superior to one that can offer no solution. The solution, itself, must be plausible; otherwise, it is simply magnifying the problem of the existence of a phenomenon by requiring justification of the existence of an even greater phenomenon.
Now here, instead of saying that the existence of God needs to be possible, he is now saying that it needs to be plausible. But of course I am trying to render it plausible by attempting to show that it makes sense of reason. In doing so I am at least attempting to enhance the plausibility of theism. So to say that I must first show that the existence of God is plausible before I can present an argument that the existence of God is plausible is to involve me in an infinite regress. EXB is just begging the question here.
As for what is "oustide my experience" the existence of an external physical world is, strictly speaking, outside my experience, in that it is consistent with all my experiences that there is no external world and that I am a brain in a vat being given experiences of objects that have no external reference. In other words, it is perfectly possible for me to have the relevant experiences in a world in which the objects do not exist, just as it is possible for me, after using a liberal amount of Jack Daniels to be, as philosophers would say, "appeared to red-goatly" even if there is no red goat in my presence. So EXB's burden of proof argument is a road to radical skepticism about a lot more than just religion.
I will leave EXB"s criticisms my critique of materialism for another occasion, pointing out only that I have dealt in some detail with criticisms of the various arguments from reason on this blog, including those of Richard Carrier. In fact, I redated three of those responses to the past month. Link