J. P. Moreland is a professor of philosophy at Biola University and has done some great work on the argument from consciousness. He summarizes the argument as follows:
”Mental events are genuine nonphysical mental entities that exist.
Specific mental and physical event types are regularly correlated.
There is an explanation for these correlations.
Personal explanation is different from natural scientific explanation.
The explanation for these correlations is either a personal or natural scientific explanation.
The explanation is not a natural scientific one.
Therefore, the explanation is a personal one.
If the explanation is personal, then it is theistic.
Therefore, the explanation is theistic.”[i]
Mental Events are Nonphysical
The layman, and especially a layman atheist who is considering this, may feel that the most unwarranted premise is premise 1 – that mental events are nonphysical. However, strangely enough, very many atheist philosophers seem to agree with this. This is because many philosophers of mind allege that mental events are “emergent” or “supervenient” and are not reducible to brain events. Eliminative materialism, which says that mental events are nothing but brain events is a somewhat popular way of thinking among naturalists, but certainly not among philosophers of mind. Why? Eliminative materialism is very implausible, because it just so obviously contradicts our experience. We know that the experience, for example, of having a thought is not (or not just) a chemical reaction in the brain, or a neuron firing. There is this other element – our experience of it. And mental events have propositional content, while neurochemical processes do not. The experiential element is clearly real, but if eliminative materialism is true, then there is just no such other element. Also, eliminative materialism leads to some absurdities. Probably chief among them is that if all mental events are nothing but brain events, then it becomes difficult to see how reasoning could happen. If it is true that mental events are just brain events, then there can be no propositional content in our thinking. Chemical reactions and firing neurons don’t have propositional content. Our reasoning relies on the content of propositions. If our thoughts are nothing but brain events, then there is no propositional content in our thoughts, and consequently, we can’t really reason. This means that any reasoning process, including the one leading to eliminative materialism, is invalidated. Thus, eliminative materialism is self-defeating. This is just a sample of the problems with eliminative materialism. But the point is that many philosophers of mind just don’t find this way of thinking about the mind convincing at all. Some (atheist) philosophers, such as Colin McGinn and Jerry Fodor, believe that we will simply never be able to explain the mind, because of a number of problems (some of them already discussed). Suffice it to say that the idea that mental events are just brain events is very implausible, but then it becomes a question of figuring out what best accounts for the clearly nonphysical aspect of mental events.
Naturalists may still claim that, even though mental properties are “emergent” they are still ultimately dependent on the physical in some way. Another strategy is to say that they are sui generis (in its own category or unique). This wouldn’t damage the claim that these naturalists admit that mental properties are nonphysical in some way (it need not be a supernatural way), which means that the first premise is still established. The argument from consciousness simply contends that God is a better explanation of those entities than the rival naturalistic theories. I’ll give a few reasons why now.
As Moreland notes, to say that mental properties are sui generis is to reject an essential component of naturalism: the belief that everything can be explained in terms of the natural sciences and that everything that is came to be through the laws of nature working on the initial conditions of universe. These are very central to the naturalist ethos, and arguably anyone who rejects them is no longer a naturalist. In other words, it is a de facto admission that a naturalist metaphysics and epistemology cannot account for mental properties. It also commits naturalists, as Moreland puts it, to “contingent brute facts” that can’t be explained in terms of anything else that exists and whose existence is not metaphysically necessary ( and so could have failed to exist). If something could have failed to exist, there must be an explanation as to why it exists. This means that the notion of a “contingent brute fact” is probably a contradiction in terms.[ii] Also, to say that mental events are sui generis is to admit that mind is non-reducible and a fundamental feature of reality. As I noted under the moral argument from responsibility, if mind is a fundamental feature of reality and is non-reducible then it cannot have a material explanation and the most natural explanation of it would be another mind. As we saw, human minds are contingent (so they must have an explanation) and human minds all began to exist, so they must have a cause or causes. Even if more contingent minds are the causes of human minds, it must eventually terminate in a metaphysically necessary mind. Otherwise, the chain of contingent minds will form an infinite regress (refer to arguments against an actual infinity under the Kalam Cosmological Argument). If every contingent mind requires an explanation, then we would need a contingent mind to explain every contingent mind…ad inifinitum. This means there should be a metaphysically necessary mind capable of creating human minds, and Ockam’s Razor makes it unreasonable to posit more contingent minds that caused human minds before reaching the metaphysically necessary mind.
If naturalism is true, then everything should be fully explainable in terms of nature or matter. If mental properties cannot be sufficiently explained by brain events, then we have encountered something that is nonphysical. You might say that mental events are “caused” by brain events, so that the nonphysical mental properties are still ultimately “natural.” There is a problem with this however. A brain event cannot simply cause a mental event and then allow it to sort of operate on its own, because how could it operate apart from the brain or some other physical substance, if it is ultimately constituted by the physical brain? Even if mental events are produced by the brain, but then somehow operate independently, this would provide evidence against naturalism, because it would imply that the mental event could operate independently of any material thing. One might respond that the mental event is both caused and sustained by the brain event. But nevertheless, this would still leave the question of how a physical something can create a nonphysical something. In addition to that, it would then be pertinent to ask if the brain event both causes and sustains the mental event, why is the mental event so significantly different from the brain event? It seems that if a brain event causes something to exist and keeps it in existence moment-to-moment, we are very close to eliminative materialism once again. Mental properties should not have their own, and completely different, quality and nature if they were so completely dependent on brain events. It is also reasonable to suppose that things that are so closely sustained by a different structure would not be “intrinsically characterizable”. That is, it should not be possible to describe such an ontologically dependent structure independently from the things on which it is dependent. But mental events are intrinsically characterizable. Mental events can be sufficiently described completely independently of the brain. In addition to this, if mental events cannot cause anything in the physical world (or anywhere else) then it is doubtful that they exist. Things that actually exist usually have causal potency. Finally, the idea that brain events always cause mental events but that mental events cannot cause brain events (epiphenomenalism) does not cohere with our experience. We clearly experience ourselves as having thoughts, making decisions and then acting on them (and again, denying this based on brain research implies absurdities – refer to the Argument from Mental Causation and the Moral Argument from Responsibility).
It is important to note that Christianity is not committed to the idea that the mind is nonphysical. This is a good argument for God’s existence but its falsity would not give evidence against God’s existence. The Jews and early Christians believed in the resurrection of dead – that all people would be resurrected to be judged at the end of the world. According to Christian theology, God means to create a “new earth” not abandon his original purpose for creation so that all the elect would go off somewhere else into a Greek paradise or Platonic heaven. So the Christian view of afterlife is not necessarily committed to the notion that the mind is nonphysical or that it is completely nonphysical, but nor does it preclude it.
The whole is greater than the sum of its parts
Maybe the mind is like water or lightning. What we experience is different from its physical composition. The whole is greater than the sum of its parts. Some people will agree that the mind is irreducible but deny that this implies that its explanation cannot be fully naturalistic. They will argue that just because mind is different from its neurological composition, doesn’t imply that there is some extra component. However, every time we observe something where the whole is greater than the sum of its parts, we can explain exactly why this is the case by pointing out what each constituent part contributes to the whole. But we can’t do this with the mind without extinguishing it. It remains inexplicable on naturalism. It is also unlikely that it will ever be explainable in terms of science. If we learn more about the brain, our understanding of the neurological circuitry will become more complex. However, the problem of explaining a first-person experience in terms of impersonal brain mechanisms will always remain. No matter how complex our understanding of the brain becomes, we will always be dealing with fundamentally impersonal, unconscious, processes or mechanisms. Purely physical brain processes would still have problems accounting for phenomenological aspects of the mind, like mental causation and free will. This response is tantamount to the contention “it still might have a naturalistic explanation”. Sure it is possible, but based on the information we have it looks very unlikely. And this is invalid as a response in the same way that “it might still have a supernatural explanation” is invalid as a response to atheist arguments.
Neurology shows that the mind depends upon the brain
You don’t need modern neurology to notice that the physical state of the brain influences the mind. If you drink two glasses of wine, this will affect your mind. If you are physically tired, or very hungry or very thirsty, this will have an effect on your mind. But from this it doesn’t follow that the mind is sufficiently explained by the brain or that the mind is the brain, or that the brain is the only thing causing events in the mind. As we’ve already seen, we know from experience that the process happens the other way around as well – that the mind causes other mental states (or brain states) (and as I said, denying this based on brain research results in absurdities – look at the Argument from Mental Causation) One hypothesis consistent with the brain research is mind-brain identity. But a hypothesis that is consistent both with the brain research and our experience is one contained in Karl Popper and John Eckles’s book “The Self and Its Brain.” Here it is conceived that the mind is the pianist and the brain is the piano. If the piano is damaged or out of tune, that limits what the pianist can play and what the audience will hear. In the same way, if the brain is damaged, this limits what the mind can do with its apparatus. This acknowledges modern brain research without reducing the mind to the brain. The mind is still an independent entity that has causal potency ( which recognizes our experience). Thus, this hypothesis has more evidence going for it (than mind-brain identity) because it accounts for both the brain research and our first-person experience of consciousness. The mind-brain identity thesis accounts only for the brain research, but cannot account for our first-person experience of consciousness. To illuminate this further, we can look at what David Chalmers, the Australian philosopher of mind, calls the “hard problem of consciousness.” We can describe all of the behaviour and sensory apparatus of human beings adequately through only the brain. But why does this process not happen “in the dark” as it would in a machine? Why is there a way it is like for us “on the inside”? Why is there a quality of experience for us? The mind-brain identity thesis cannot account for this phenomenon.
[i] J.P. Moreland, “The Argument from Consciousness”, in The Blackwell Companion to Natural Theology, ed. J.P. Moreland and William Lane Craig (West Sussex: Wiley-Blackwell, 2009) Loc. 7837, Kindle Edition
[ii] Ibid., Loc. 7626