I'm still really busy, but an objection occurred to me regarding Craig's recent defense of the Leibnizian cosmological argument, and I'd like to get some feedback to see whether I'm on to something. If I am, then I'd like to add the point to a paper I'm working on. Here is a first pass at the criticism. Feel free to have at it while I'm away!
On another occasion, I argued that Craig has so far failed to justify a seemingly crucial claim in his revived Leibnizian cosmological argument, viz.,
PQFE: It’s possible that the fundamental constituents of material reality (quarks, say) fail to exist.
Here is a more worrisome objection. Even if Craig were to justify PQFE, it wouldn't help him infer
QNEG: The fundamental constituents of reality (quarks, say) have a necessary being as their explanatory ground.
Indeed, I will demonstrate the stronger claim that even if Craig were to justify PQFE, it would fail to provide evidence that would even slightly favor QNEG over at least one epistemically possible naturalistic rival hypothesis.
The Leibnizian cosmological argument is often presented in a way that suggests that there are only two possible sorts of beings:
(i) contingent, dependent beings
(ii) necessary, independent beings
If one could justify such a categorization, then one could properly conclude that all contingent beings are dependent, in which case one will have gone a considerable distance toward justifying the inference to a necessary, independent being as their explanatory ground.
However, this categorization of beings is dubious, for two reasons. First, necessary dependent beings seem epistemically possible. Indeed, Christian philosophers often take the second person of the trinity to be just such a being. On the sort of account I have in mind, God the father is a necessary being, and he necessarily and eternally wills the existence of the Son as an act of essence. On this account, then, the Son exists in all possible worlds, and is thus a necessary being. However, despite this, his existence is dependent on the causal activity of at least one other being, viz., the Father. Therefore, on this account, God the Son is a necessary yet dependent being.
Second, contingent independent beings seem epistemically possible. Indeed, if Richard Swinburne is right, the first person of the trinity is just such a being. For on his account, God the father is a merely factually necessary being. Thus, God the father is a being that fails to exist in at least some possible worlds. However, he is an existentially independent, free-standing being who is everlasting and indestructible at all the worlds in which he does exist. Therefore, on Swinburne's account, God the Father is a contingent yet independent being.
In light of the preceding, then, it appears that the previous categorization of types of beings is inadequate, and that a more neutral way of carving up epistemically possible space would look like this:
(i) contingent, dependent beings
(ii) contingent, independent beings
(iii) necessary, dependent beings
(iv) necessary, independent beings
One implication of this categorization will prove important for our purposes: one can’t automatically infer “dependent” from “contingent” without further argument.
So that’s the setup. Here’s the punch line: It’s epistemically possible that the fundamental constituents of matter (quarks, say) are contingent yet independent beings. But if so, then it's epistemically possible that such beings fail to exist in at least some metaphysically possible worlds, and yet they lack an explanation for their existence beyond the de facto lack of things that can annihilate them in the actual world and the relevant counterfactual worlds. And if that's right, then even if Craig's account of conceivability is a good guide to metaphysical possibility, and even if we can properly conceive of the non-existence of quarks, such modal evidence fails to justify the claim that quarks are dependent beings requiring a necessary being for their explanatory ground. For while such conceivability evidence is just what one would expect if quarks were contingent dependent beings, it’s also just what one would expect if quarks were contingent independent beings. But while the former is a theistic hypothesis, the latter is a naturalistic hypothesis. But if so, then the evidence from conceivability doesn't favor the theistic hypothesis over the naturalistic hypothesis.