I’ve had the honor of being rebutted by prominent atheist Jeffrey Jay Lowder over at Secular Outpost. Lowder replied to my post on whether or not extraordinary claims require extraordinary evidence. Before you continue reading, I’d like to point out that I am no expert. I do not hold a PhD in anything and I am a fallible human. So if I’ve missed a point, straw-manned Lowder, or am just plain stupid, please point out my error in a loving way. Cheers!
Lowder’s post is most easily understood in two parts: first, in reply to ‘extraordinary claims,’ second, in reply to ‘extraordinary evidence.’
Regarding the first part, it appears that he and I largely agree: whatever is an ‘extraordinary claim’ stems from a subjective viewpoint, conditional upon one’s background information alone. In fact, Lowder compliments, “So the objector is correct that the Bayesian interpretation is inherently subjective in the sense that it depends entirely upon what a person knows and believes.” But he continues, “So what? It doesn’t follow that we can’t figure out what are extraordinary claims.” I think he is correct for thinking this. But this isn’t quite saying much. It just means that everybody has their own subjective thought-journeys through the wilderness of knowledge. And if that is all it really means, then it doesn’t really seem to a strong point against other people’s subjective epistemologies trying to figure out the objective world.
Regarding the second part, Lowder nicely points out that the same Bayesian probability formula is used for both ordinary evidence and extraordinary evidence. So why use the ‘Extraordinary Claims’ slogan? He writes, it “emphasizes the common sense notion that the more implausible (i.e., antecedently improbable) we initially regard a claim prior to considering the evidence, the greater the evidence we will require to believe the claim.”
When Lowder writes, “we initially regard a claim” he means that whatever should be considered ‘extraordinary evidence’ is contingent upon if something is an ‘extraordinary claim.’ But as we have already seen, whether something is an extraordinary claim or not is completely subjective. Put another way, whatever is a “common sense notion” to Lowder might be or not be a common sense notion to someone of a different, subjective epistemology. So we don’t seem to have good reason for accepting that there’s some sort of objective standard for categorizing evidence as ‘extraordinary.’ Perhaps Lowder will agree with me here. Calling a type of evidence ‘extraordinary’ is conditional upon one’s background knowledge, and therefore subjective. And since it is subjective, the slogan is only true if it reaches a hearer who has the same subjective epistemology. Let’s face it: the emperor is butt naked.
If Lowder can illustrate that both ‘extraordinary claims’ and ‘extraordinary evidence’ comply to the same Bayesian probability formulas as ‘ordinary claims’ and ‘ordinary evidence,’ then why not just drop the adjectives altogether for the sake of discussion and say, ‘We have all claims C here and we have all evidence E here, let’s figure out what C’s are true given E’? Reformed epistemology aside, this suggestion would seem to be something both naturalists and theists could agree.