Victor Reppert thinks that if materialism is true, there can be no logic and no "laws of evidence". And therefore, the claims of materialistic atheists - that they base their beliefs on logic and evidence - are self-refuting.
In my previous post, I agreed with John Loftus that people like Victor Reppert are ignorant of the arguments or philosophical stances of naturalists. Victor is fond of pointing out what he thinks are logical inconsistencies in the beliefs of atheists and naturalists. His argument typically takes this form:
1. Naturalists believe A, and they believe B.For example, A might be the proposition that mind is physical, and B might be the proposition that there is nothing mental at the base level of physics. The naturalist accepts both A and B, and sees no logical conflict between them, because he understands that while mind doesn't exist at the base level, it is an emergent phenomenon that results only from the mutual interactions of physical objects in highly complex configurations. Victor, on the other hand, adds in an additional assumption of his own:
2. But A is logically incompatible with B.
3. Therefore, naturalists belief in both A and B is illogical or incoherent.
2a. If a phenomenon can't be explained at the base level of analysis, then it can't exist.So according to Victor, because naturalists agree that fundamental physical particles, when viewed in isolation, have no mental properties, then it is illogical to think that any configuration of physical particles could exhibit the kind of behavior we call mind. And no matter how many times you explain to him that naturalists don't accept his implicit assumption 2a, and they have plenty of evidence to serve as the basis for for what they do believe, he goes on insisting that the naturalists' position is incoherent. But if the naturalist doesn't accept 2a, there is no logical inconsistency between A and B. And that's something that any philosopher should find acceptable.
Victor fails to understand the position of the naturalist despite the fact that it has been explained to him ad nauseum. Now, it's one thing to disagree with that position. As a theist, Victor is predisposed to accept the metaphysical and philosophical views that support his own theistic beliefs, and that's fine. But as a philosopher, he should at least be capable of understanding the arguments of those who don't share all of his assumptions, and of judging their logical validity based on that understanding. And this is the real basis for an exasperated Loftus saying that he is ignorant. Explain it all you want. Those explanations have no impact on his analysis. Victor could conclude that naturalists are wrong because they don't accept HIS suppositions, but instead he claims that they are incoherent because their own arguments are logically inconsistent.
And now, Victor is once again doubling down on the same kind of analysis. He presents a different version of his argument in a new post here. Victor insists that naturalists can't employ logic or "rules of evidence", because by their own admission, mind is a deterministic physical process. Basically, proposition A is the claim that atheists base their beliefs on evidence and logic, and proposition B is the assertion that brain processes are physical. Victor believes that these two propositions are mutually incoherent, because he makes the additional unstated assumption 2a: that evidence and logic are not derivable from anything that is purely physical. But once again, this 2a is not something that a naturalist would agree with - it is just something that Victor presumes because it is consistent with his own theistic belief system. And as with the previous example, if the naturalist doesn't accept 2a, there is no logical inconsistency between A and B.
As it happens, a naturalist who accepts an empiricist epistemology can make a good case that logic itself is physical - that is, it is a reflection of physical reality - and that our understanding of logic is based entirely on observed evidence. For a true empiricist, the evidence of the senses is the one and only basis we have for believing anything at all. That is the case for the axioms of logic, our understanding of mathematical principles, and the laws of physics, as well as our naturalistic metaphysical beliefs. Everything we know (or we think we know) ultimately comes down to what we have observed in the physical world, and in many cases, making inductive generalizations about those observations. From an empiricist's perspective, this is the true basis of our formulation of the rules of logic. I have discussed the topic in my post Where Does Logic Come From?
But again, Victor will have none of that. He makes his own theistic presumptions, and on that basis, declares the naturalist to be incoherent - not because the naturalist's own statements are logically inconsistent, but because they don't agree with that presumptions that Victor takes for granted. The question of free will versus determinism is just a red herring - it really has nothing to do with it. Whether we freely choose our logical processes, or we are simply following a chain of thought that is mechanistically determined, we still apply the rules of logic that we understand from our experience in the physical world, and evidence still consists of the things we observe through our senses. (What exactly Victor means by the term "laws of evidence" is unclear.) The process of following evidence and applying logical rules is not an illusion. It is only the notion that our minds are somehow free to operate in the physical world without being subject to physical causality that is an illusion. And as I said, there is nothing about logic that implies any kind of immaterial woo.
But try to explain all this to Victor. Try to show that there really is no logical inconsistency in the materialist stance. It will roll off him like water off a duck. It will have no effect on his arguments, because he just ignores the arguments of the materialist, as if he had never heard them. I wouldn't object if he just disagrees with those arguments, and presents his own case for the contrary position, but Victor goes beyond that, and makes the claim that the materialist disagrees with himself. And his basis for making that claim is without merit. If he understands the materialists' arguments, he could then either accept that they are indeed logically coherent as a set of stand-alone propositions, or explain why they aren't with something more substantial than merely asserting his own beliefs as if they are beyond dispute. Why can't mind exist in a purely physical world? And why can't a physical process employ logic? He has never made a cogent case for these things. He simply thinks that we should all just accept those assumptions, as if they were gospel.
And that's exactly why he fails to see the logic of any perspective other than his own. He ignores the arguments that have been made, and all the scientific evidence that backs them up. And he wants us to believe that he's the one who follows the evidence.