Initial Rejoinder to Craig

***NOTE: A substantially revised and expanded reply can be found here.***

As previously noted, someone recently put some of my criticisms of the Leibnizian cosmological argument to William Lane Craig, and Craig offered a reply. I offer a rejoinder below:

Craig's most important reply is his charge that my key criticisms entail an untenable modal skepticism:

We generally trust our modal intuitions on other familiar matters (for example, our sense that the planet Earth exists contingently, not necessarily, even though we have no experience of its non-existence). If we are to do otherwise with respect to the universe’s contingency, then the non-theist needs to provide some reason for his scepticism other than his desire to avoid theism.

My reply to this objection is similar to the one I offer in a paper I'm currently working on (with some modifications. See below):

"One might object that my criticism relies on an arbitrarily selective form of modal skepticism, on the grounds that the demand for justification for exotic possibility claims should then apply to the humdrum possibility claims as well. And since we accept the latter without argument, we should, to be consistent, accept the former. But this objection is unpersuasive. For a number of plausible accounts of our knowledge of possibility have been proposed that allow for knowledge of humdrum metaphysical possibilities, while leaving exotic possibility claims unjustified. For example, it has been proposed that our knowledge of metaphysical possibilities is grounded in (i) our facility with counterfactual reasoning in ordinary contexts[1], (ii) our folk theory of how the world works[2], and (iii) arguments from analogy/relevant similarity with the actual world[3]. Such accounts can nicely explain the epistemic force of relatively uncontroversial thought experiments involving humdrum metaphysical possibilities (e.g., the Gettier cases), while leaving the more "far out" or exotic modal claims unjustified (e.g., "it is possible that I exist apart from my body", "it is possible that an Anselmian Being exists", etc.). Most saliently for our purposes, it appears that such accounts leave Craig's modal claim involving the possible non-existence of the fundamental constituents of reality[4] unjustified: it's not clear how such a claim could be justified via relevant similarity with the actual world, our folk theory of how the actual world works, or our facility with counterfactual reasoning in ordinary contexts.


Marc said...


Hello. Hope the examined life is treating you well.

Quick question(s).

How do you, and/or modal epistemologists in general, define or characterize what constitutes an "exotic possibility claim"? And assuming that we have an intuitively acceptable definition or characterization of "humdrum possibility claims," how might we differentiate between them when it's not immediately obvious that a given possibility claim is humdrum or exotic?

I'm not terribly conversant in modal epistemology, so I don't know if there are answers to these questions which are considered standard or orthodox, or which enjoy relatively widespread assent. If not (which, I imagine, is likely), how are you inclined to approach these issues?

-- Marc

exapologist said...

Hi Marc,

Thanks very much, my friend. Likewise!

I offer an account of the distinction in my dissertation, if you're interested, but in recent papers, the degree to which a thought experiment or possibility claim is humdrum or exotic is commonly considered a function of its degree of similarity to the actual world. Think Lewis-Stalnaker semantics, and the notion of "close" vs. "distant" worlds.


Marc said...


Thanks. I'm indeed interested in the account you offer in your dissertation, particularly since some of your objections to the Leibnizian contingency argument seem influenced by your form of modal skepticism.

-- Marc