On the Grab Bag

Joshua Frear, of Pennsylvania, writes the following commentary about C. S. Lewis's Dangerous Idea on his blog. His comments are in red.

Reppert and CS Lewis: The "Grab bag" and Reduction

I read Victor Reppert's book, C.S. Lewis's Dangerous Idea over break. As Lewis and his writings continually inspire and challenge me, it was very cool to read a book attempting to formalize Lewis's argument from reason. The gist of the book is that Lewis's argument (which I will describe in a second) is actually a good analytical philosophical argument. Lewis argued in the 3rd chapter of Miracles something like this:1. Naturalism tells me that my brain is no more than an aggregate of molecules interacting according to nonrational causes.2. If the thoughts in my brain are caused by nonrational causes, then I have no reason to trust their rationality.3. Thus, if naturalism is true, then I have no reason to trust my thought process that informed me it is true.While I enjoyed Reppert's attempts to formalize Lewis, it felt unsatisfying. Reppert offers 7(!) different formulations. My initial reaction was that these werenothing more than a "grab bag" of the traditional objections to reductive naturalism.However, on reflection, I realized that this "grab bag" is actually not to be despised. Assuming that the world is structured the way Lewis thought it was, a reductive program would explain most phenomena, but not all. There would be various unexplainable phenomena scattered around, troubling us. That is indeed what we see. While I am still dubious of the stylistic value of offering 7 equally competing formulations, I respect the "grab bag" much more now.

Joshua: Yes, there were difficulties with the idea of subdividing Lewis's argument to this extent. But I believe that Lewis's line of argument really subdivides into this many strands of argument, and unless you separate them, the different strands of argument will start tripping over one another. There are several aspects to the rational inferences that we all rely on to know what we (naturalist or not) think we know, and all of these are, in my view deeply problematic for the naturalist. On the other hand, I probably didn't get to develop any one line of argument as well as I would have liked, and some, like the argument from truth, are presented very sketchily indeed. But if all of this is worth its salt, then I am neither going to be the first or the last person to work on these arguments, and further development is both possible and forthcoming. I have some new things to say in my proto-response to Carrier here. In addition, Bill Vallicella has done some things with the argument from truth here and here, though we have yet to see his full version of the argument. See also his discussion of logical laws here, here, and here.

But I do fully understand the weight of Josh's concerns about the grab-baggish-ness of the arguments in the book.