In my recent dialogue with Justin Schieber we had an interesting exchange on Justin’s commitment to a position he refers to as “naturalism”. To get the most out of this article, you should begin by taking ten minutes (or so) to get the background exchange. You can start watching from here.
In this exchange, Schieber adopts Paul Draper’s view of naturalism which, according to Schieber, is the view that “The natural world is a causally closed system and what this means is that there’s no outside entities or forces that are able to causally interact within the natural world….”
In response, I point out that Schieber’s definition of naturalism entails that no type III civilization (according to the Kardashev scale) created this universe (i.e. this “natural world”). But Schieber has no way of knowing whether any type III civilization created this universe. Thus, Justin’s commitment to “naturalism” is unjustified.
Justin’s response is to say that his commitment to naturalism is probabilistic. He then suggests that it is simpler to suppose that no type III civilization created the universe. However, this is at best an unjustified claim, particularly given the evidence for cosmic fine-tuning. In other words, one cannot determine which explanation is simpler without first considering what is the total data set to be explained.
Thus, Justin’s commitment to naturalism (as he defines it) is unjustified. At best, Justin should be an agnostic with respect to the claim of naturalism.
Edit: Some folks might be inclined to reply, “Okay, by ‘natural world’ I mean to refer to a metaphysical entity that would include any Type III civilization that might exist.'” Right. That’s not ad hoc at all (excuse the sarcasm). Indeed, if you’re going to go that far you might as well say “Okay, by ‘natural world’ I mean to refer to a metaphysical entity that would include any God that might exist.'” In other words, by making this ad hoc, rearguard move, “naturalism” is effectively reduced to little more than a vacuous cipher for “I believe that whatever ultimately exists is what ultimately exists.”