A Christian apologist writing under the pseudonym ‘InvestigativeApologetics’ stated the usual objection to atheism, namely, that it’s impossible to prove or give evidence for the non-existence of God.

The fact is that atheists who yell that “there is no evidence for God (or Christianity)” are protesting too much, so to speak, and they are, in fact, projecting the weakness of atheism onto theism. For truth be told, it is atheism, at least when in its wide and positive sense, that is the view for which there is no evidence or argumentation that could establish its position. (LINK)

I responded as follows:

Yawn. InvestigativeApologetics seems completely oblivious about the ways to establish the truth of atheism. 

LINKS: here, here

InvestigativeApologetics then doubled down on his original claim, but with a very novel justification.

Yawn all you like. I am intimately familiar both with those two links and with the various Evidential Arguments that you present at the Secular Outpost. In fact, funny enough, it was your arguments that inspired me to look into this matter and come to the conclusion that I did concerning the un-evidenced nature of atheism (when viewed broadly and positively).

Now, obviously, I cannot show this conclusion in this particular comment (although further comments may follow) and I am simultaneously–at this point in my life–beyond caring whether people are swayed by my points or not (for convincing a flesh-and-blood person is not the same as having a convincing argument). However, let me just make a few quick points:

1) First, I am not saying that we must prove that a god does not exist with certainty in order to be rational to believe that a god(s) does not exist. Rather, I am saying that the atheist cannot even show that it is more probable than not that a god does not exist…at least not without begging the question in a substantial number of ways that the theist or skeptic need not grant.

2) For example, consider all the evidential arguments that you present on the Secular Outpost in light of the Likelihood Principle (that a data/observation counts as evidence for Hypothesis 1 over Hypothesis 2 if the data/observation is more likely or expected on Hypothesis 1 than on Hypothesis 2):

a. The Evidential Argument from Scale (AS) – Given the kind of being described in my first comment, no specific scale of the universe would count as evidence against its existence, and all “scale types” would be equally expected on both naturalism and that form of theism. Thus, no evidential support for naturalism (and I know that you don’t fully or strongly endorse the argument from scale, but I wished to present it anyway). 

b. The Evidential Argument from the History of Science (AHS) – This argument was ripped apart in a past discussion that I remember (with Crude and CL and others, I believe…I’m sure you will disagree, but that is not surprising given that philosophy is a discipline of disagreement), and it has (at my last count) at least 10 flaws, but its worst flaw is that it assumes both that there is such a thing as “matter” and that there is such a thing as a “naturalistic” cause (or explanation), but neither of these need be accepted by the theist or skeptic, either of whom could be an immaterialist (or a-matterist) and/or an occasionalist (where God is the only true cause). So your argument rests on an assumption that need not be conceded, and hence, the argument is flawed from the start. It is also circular given that you need to deal with the objection from the occasionalist, but to do that, you cannot assume a natural cause, which is what the occasionalist denies; you would either have to disprove occasionalism or disprove the existence of any god through other means, but this, in turn, makes your argument redundant. So the argument is either redundant or begs the question. Not a good state for an argument to be in. Furthermore, even if the existence of “naturalistic” explanations was conceded, it would still be the case that if a deist non-interventionist god existed, we would expect all explanations to be naturalistic even on this type of deism, and so again, there is no evidential value in favor of naturalism or deism with this argument as naturalistic explanations would be equally likely on both worldviews.

1. InvestigativeApologetics’ comments about the AHS are confused. Theism,’ as I have defined it, is the ‘core‘ explanatory hypothesis. Sectarian doctrines like occasionalism and non-interventionism are auxiliary hypotheses, viz., theism does not entail occasionalism or non-interventionism but is compatible with both. They are at, at best, uncertain. The probability calculus specifies how we should deal with uncertain auxiliary hypotheses in a way that conforms with the pattern of probability relations specified by Bayes’ Theorem. I explain this here. What IA needs to do is provide an antecedent reason on theism for expecting that either or both of these auxiliary hypotheses are significantly more likely than their denials. Otherwise, the logically correct conclusion is to dismiss these objections as ad hoc, “just so” stories invented solely to avoid the conclusions of the arguments. “Both worldviews” might have roughly equal explanatory power, but naturalism would trump deism by virtue of having a greater intrinsic probability.

2. More important, a careful reading of my arguments will reveal that my arguments need not presuppose that material objects exist.  Supernaturalism (or “source idealism”) can be defined in a way that is neutral between dualism and idealism.  (The hypothesis that the original causes of any material objects that exist are immaterial does not entail that material objects exist.)  Similarly, naturalism or “source physicalism” can be defined in a way that is neutral between dualism and materialism.  Notice too, that even if my particular definition of supernaturalism implies the existence of material objects, that is compatible with “identity idealism”, which is far more plausible than eliminative idealism, just as identity materialism is far more plausible than eliminative materialism.  (Berkeley was an identity idealist, for example.  He believed that physical objects exist, but thought they were collections of ideas.) (I owe this point to Paul Draper.)

c. The Evidential Argument from Biological Evolution (ABE) / The Evidential Argument from Physical Minds (APM) / The Evidential Argument from Evil: The Biological Role of Pain and Pleasure (AE: APP) / The Evidential Argument from Evil: The Flourishing and Languishing of Sentient Beings (AE: AFL) / The Evidential Argument from Evil: The Self-Centeredness and Limited Altruism of Human Beings (AE: AVV) – See Point (a) – Again, none of these arguments hold any evidentiary weight against a non-interventionist god and so do not support naturalism over such a deism given that all these facts would be equally likely on naturalism or deism.

Now, to be precise, my “arguments for naturalism” are really arguments against theism, though in some sense they are of course both.

Now, you could, of course, try to claim that aspects of prior probability or modesty/coherence (from Paul Draper’s ‘Burden of Proof’ Argument, which I know you support) might make atheistic-naturalism more rational or more likely than some type of theism. But again, there are numerous problems with such maneuvers. First, prior probabilities are notoriously difficult to establish objectively, and I, on that basis alone, I would be suspicious of any argument, by an atheist, which just happens to show that atheism (or atheistic-naturalism) has a higher prior probability than theism.

IA knows very well that suspicion is not an argument. And notice that IA gives no reason to doubt that intrinsic probabilities should be determined solely by scope and coherence. Furthermore, he neglects to mention that Draper’s theory of intrinsic probability does result in the conclusion that naturalism and supernaturalism have equal intrinsic probabilities. Once that fact is taken into consideration, it becomes clear that Draper’s theory is not biased against supernaturalism. The fact that theism has a smaller intrinsic probability than supernaturalism follows directly from the definitions of supernaturalism and theism. Theism entails supernaturalism but supernaturalism does not entail theism. So the probability of theism cannot be any greater than the probability of supernaturalism but could be less. This is basic, non-controversial set theory.

Second, in all your arguments (and your priors) you begin with the assumption that materialism—in the sense of metaphysical matter actually existing—is true, but I do not concede this assumption (being an a-matterist and thus lacking a belief in the existence of matter) and so this must be proven before any one of your arguments gets off the ground and before you can even set the prior probabilities that you want. Third, modesty and coherence does not favor naturalism, but rather a type of Berkelian immaterialism, for it is that view that makes the least assumptions about reality (only thinking things exist, which we cannot deny, and is thus the most modest) while remaining coherent (and it is arguable that atheistic-naturalism even is coherent), so Draper does not help you much.

Addressed above.

Fourth, even if we grant the existence of matter, given the fact that a “material god” could exist, and given that a good case could be made that the prior probability of a “material god” existing is either just as good or better than the prior probability of straight atheistic-naturalism (for consciousness, language, life, would have a higher probability of existing given the existence of a material god than given just straight atheistic-naturalism), then, once again, your arguments run into trouble.

What is a “material god”? The word “material” tells us that such a being is composed of matter. The word “god,” I gather, is supposed to tell us that such a being has supernatural powers or abilities. The hypothesis that such a being exists is a very specific version of supernaturalism and so, like theism, has a smaller intrinsic probability than supernaturalism and naturalism. (The more a hypothesis claims, the more ways there are for that hypothesis to be false and so the lower the intrinsic probability.) So-called ‘theistic evidences’ — such as consciousness, language, life, and so forth — determine the explanatory power of the ‘material god’ hypothesis, not its intrinsic probability. Furthermore, notice that IA lists only alleged theistic evidences. It seems rather one-sided to estimate the probability of a material god existing by considering only theistic evidences, while ignoring naturalistic evidences (such as pain and suffering, evolution, nonresistant nonbelief, mind-brain dependence, and so forth). Once the evidence is fully stated, it’s doubtful that IA’s “material God” exists.

Now, I am certain that you might scoff at certain proposals that I have put forward (for example, immaterialism or occasionalism) as being not worthy of consideration. And that’s fine. But my point is this: I do not need to concede to the very assumptions which are latent in so many of the arguments that you put forward, and the moment I do not concede to those assumptions, not only do your arguments lose nearly all their force (if not all), but you actually have the burden to prove the things that you are asserting. And demonstrating such things (such as the actual existence of matter, for example) is a very difficult task to say the least. Furthermore, until and unless you do demonstrate the existence of these things you just essentially assumed, I could readily contend that you hold to them with little more than blind faith. And so these are just some of the brief reasons why, when atheistic arguments are thoroughly deconstructed, and when we realize the various underlying assumptions that they make—assumptions which we need not grant—and when we also understand that the atheist is literally denying the existence of all reasonably possible gods, which could and would include a god such as a non-interventionist one, then we can begin to understand why the atheistic position, when viewed broadly and positively, lacks any evidence for its claim. 

I’m not sure about “scoffing,” but I will say this. If the best response a person has to my arguments is to doubt or deny the existence of matter, then I’m feeling pretty good about the arguments. This must be how Christians feel when atheists use certain far-fetched objections.(“If this is the lengths they have to go to in order to deny the argument, then let them have it.”)