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Brain split between atheism and theism

Published: 15 June 2013 (GMT+10)
Brain split between atheism and theism

A neurologist describes a case where two parts of the brain seem to have conflicting beliefs about God’s existence, and mockingly asks which ‘entity’ will go to heaven?

Stefan N. from Denmark asked about a video on which a neurologist used a case of ‘split brain’ to mock Christian views on salvation:

CMI, I ran into a great problem, and I really would like your thoughts on this.
I’d say it’s the strongest atheist arguments I’ve come by. I’m a Christian, and no matter this argument, I still do believe, but I want to logically be able to refute this finding by VC Ramachandran: Split brain with one half atheist and one half theist. Neurologist VS Ramachandran explains the case of split-brain patients with one hemisphere without a belief in a god, and the other with a belief in a god. The video can be found on youtube.

CMI’s Carl Wieland replies:

Dear S.N.

Thank you for this very interesting question. I think the problem may be caused by accepting the premise that in this tragic severing of the corpus callosum (the connection between the brain hemispheres) two separate persons have emerged. I suggest they have not, at least not in any sense that supports the dilemma that the neurosurgeon seems to claim it poses for Christian belief.

However, we know that in this life, our decision-making, our thoughts, feelings and so on are not independent of the material substrate of the brain—the material brain is intimately involved in such things.

The aim seems to be to lead to the conclusion that because of this dilemma, there therefore can be no such thing as an individual with a transcendent, non-material soul who is also capable of being held eternally responsible for his or her decisions.1 So let’s examine all that carefully, particularly the assumption that there are two persons involved here. And what makes it difficult, and what we have to bear in mind constantly, is that we are dealing with pathology here—a tragic thing in our fallen world—not with a normal situation.2

Normally, upon thinking of a ‘person’, we would readily (and understandably) associate this with many things, not just the capability of holding individual opinions or beliefs. It involves also an individual notion of the self, as well as a separate rational, autonomous will, for instance. Though the details are scanty, and one has no chance to ask clinically relevant questions, let’s assume for the sake of the argument that the observation has demonstrated at least part of that whole package, namely that there are two separate ‘entities’ capable of separate ‘will’—at least to the extent that one of them chooses not to believe in the existence of God, whereas the other apparently does. An important question is, how far does that ‘separateness’ extend? This is important because the neurosurgeon poses a question, albeit semi-facetiously, to the Christian; would the entity that believes go to heaven while the entity that claims to have no belief in God go to hell? Let’s leave aside the dubious theology that mere ‘belief’ saves (as opposed to saving belief as per the Gospel good news, in which the object of the belief is the crucial part, not just some vague belief in a God—which the demons also share (James 2:19).

Notice that in posing the question, the neurosurgeon has permitted the argument to now be framed in Christian terms, i.e. if we Christians are challenged on our turf, we have a right to make assumptions in our reply that are based on that very framework that is being attacked, i.e. biblical Christianity. So let’s do that; from the Bible we can deduce that there is in fact an immaterial aspect to humanity, to any individual. Call it the ‘soul’ if you like (though this word in Scripture has an overlapping range of meaning, which is why I’ve defined it before I mentioned it, to clarify the sense in which I am using it here). This immaterial soul seems to be, during our earthly life, associated with the material of the brain (the matter—plus its organization, which is another way of saying its ‘information’) but is not ultimately dependent on it—such that when that material substrate dies, decays away, the ‘soul’ does not.

However, we know that in this life, our decision-making, our thoughts, feelings and so on are not independent of the material substrate of the brain—the material brain is intimately involved in such things. If it were not so, then anesthetics would not make us temporarily lose our decision-making processes, for instance, nor would mind/mood altering drugs, both legal and illegal, or intoxicants have any effect on our reasoning capacities, for example.

In short, God, as creator of the biological world, has chosen to make the brain with its amazingly complex biological machinery to somehow act as the material ‘substrate’ that connects with and interacts with the transcendent aspect of all of us. It is the vehicle through which such processes as decision-making, thinking, reasoning, etc. are carried out. And this is almost certainly true for decision-making concerning salvation issues, as well. It can therefore be deduced from the biblical existence of the soul that our non-material part is capable of interacting with the material part (brain)—and does so intimately during life. How exactly this happens is currently completely unknown, and it may in fact be unknowable. But so are large aspects of consciousness and reasoning and so forth themselves. So it’s not some copout to say that the way in which the ‘soul’ interacts with the material brain is poorly understood—this description applies to consciousness itself, which is actually regarded as one of the great mysteries of modern science, and may also turn out to be unknowable. (I say this because even some non-Christian brain scientists have suggested that the famous incompleteness theorem of the philosopher/mathematician Kurt Gödel suggests that no system is in principle capable of fully analyzing itself, hence our brain functioning may never be fully understandable by the human brain itself—in principle. See also Consciousness: a problem for naturalism.) There is also a useful section in this article Questioning God’s many attributes about one-time leading atheist philosopher Antony Flew’s refutation of the claim that the mind is nothing but a production of brain chemicals, the premise behind this video.

So the only way in which this is a dilemma for a Christian is if we assume that there are in fact two souls, each with a rational responsible power of choice/action, each somehow separately connecting to a separate part of the one brain. But how has that been demonstrated? Quite simply, it hasn’t.

In fact, it is not likely that one would even say, if one were observing this patient in their everyday life, that there were two persons in any other than a relatively trivial sense. Split-brain cases in clinical practice are very complicated, given the brain’s plasticity, but one expert comments that in such cases, “speech, verbal intelligence, calculation, motor coordination, verbal reasoning and recall, personality and temperament are all preserved to a surprising degree in the absence of hemispheric interconnection.” See this clinical article. It also says that situations that require “extremely rapid processing of very complex information that is typically handled within lateralized regions (that is, lexical and affective [word and mood—CW] processes)” may be “particularly sensitive to corpus callosum abnormality”.

So I suspect that it is likely that all sorts of other aspects of the person’s functioning would still be exhibiting as if they were one entity. That suggestion is supported by this abstract of Tim Bayne’s 2010 book The Unity of Consciousness on Oxford Scholarship Online, at this link:

“The received view within psychology and philosophy is that the split‐brain (commissurotomy) procedure3 leads to a breakdown in the unity of consciousness. Disunity models of the split‐brain can be divided into two classes: two‐streams models, according to which patients have two streams of consciousness, and partial unity models, according to which patients have a merely partially unified consciousness. Both models are motivated by the cognitive and behavioural disunities that patients exhibit in certain laboratory conditions, but they struggle to account for the cognitive and behavioural unity that patients demonstrate in everyday life. Preferable to disunity models is a full unity ‘switch’ model, according to which consciousness in the split‐brain rapidly switches between hemispheres. It is argued that only the switch model can account for both the behavioural disunities that split‐brain patients exhibit under experimental conditions and the behavioural unities that they exhibit outside of such contexts.”

Note this section in particular: “the cognitive and behavioural unity that patients demonstrate in everyday life.” In short, I am suggesting that the patient referred to in this video, though they may exhibit some bizarre things, like the left hand sometimes doing things that the right hand wants to reverse and so on, and expressing two views of God, would not likely themselves support the idea that there are two separate persons, nor would observations support that when it comes to everyday life. And Bayne seems to have concluded that such observations as there in split-brain patients can be better accounted for via an ‘alternation’ between the two centres of consciousness.

So the very notion that there are two ‘entities’ is on shaky ground. But even if the observations all fitted the idea that there were two sets of independent decisions being made by each half of the brain, I think it can be shown that it would still not create a true dilemma for Christian theology.

To explain, take this possible scenario. (Speculative, yes, but then the neurosurgeon’s question is inviting such speculation, in a way that suggests he thinks that no scenario that would resolve the apparent dilemma.) We know, for instance, that for various functions, such as language, one or other of the two hemispheres dominates. What if, then, in a normal brain, hemisphere ‘A’ is in fact intended to be dominant in the decision-making process, or in belief, or any one of a number of functions relevant to the issue of salvation? That hemisphere (which in an intact brain would be receiving ‘input’ from the other) would then be the ‘switchboard’ with which the person’s non-material part (soul) would interact, and input from the other hemisphere would not generate any contradiction. So then interrupting that flow of input from the non-dominant hemisphere may well create in effect an illusion of autonomy, or separateness, as in multiple personality disorders. And all of this could be happening while there still continued to be in fact one part—and only one—as the actual ‘centre of responsibility’. And this is the part which would, as before, be interacting with the soul and would be the true entity that could properly bear the title of the locus of the person’s capacities, etc. Now I think it is likely much, much more complicated than that, but it is trying to make the point that there is at least one possible scenario that resolves this ‘dilemma’.

In Christian theology, what is being judged is not the material substrate of the body, but the immaterial, based on actions and beliefs in life.

Consider, in that light, the neurosurgeon’s facetious question, i.e. would each entity go to a different eternal destiny? In Christian theology, what is being judged is not the material substrate of the body, but the immaterial, based on actions and beliefs in life. So since there is no reason to think that there has been anything other than only one soul all along, it is only that soul whose eternal destiny is at stake. Yes, our souls will be united with a physical resurrection body (though likely not the same atoms of matter we are made up of now, since these in any case are continually recycling throughout our life; the bones you have now are apparently not the same substance as the ones you had ten years ago, e.g.). But this ‘reconstruction’ is not a reconstruction to a past pathological state, but rather to a fully healed individual. No-one thinks, for instance, that a Christian whose brain has degenerated drastically with Alzheimer’s would have that condition in their resurrected body. So whatever the cause of the corpus callosum damage in an individual, that damage would be healed in a resurrection (even a resurrection of the unrighteous to judgement). So that person’s resurrection brain would no longer be exhibiting as if there were two centres of decision-making, so the problem vanishes by following the argument to its full conclusion.

In short, there is no reason that one cannot assume that in the sense of spiritual responsibility/decision-making, there is only one such ‘responsible’ entity at all times, interacting with the transcendent part of ourselves. And as indicated earlier, it is likely that were one to observe this person during their normal everyday functioning, it would likely match this notion. The physical resurrection body that is ‘matched’ to the soul, whether destined for hell or heaven, would in any case no longer have this split-brain problem.

Finally, it should be emphasized that it is likely from this brief video that this particular person’s belief (in at least one part of their brain) that ‘there is a God’ is nothing like saving faith, which is much more than mere assent4 to the fact of a God, and which results in a deep, spiritual transformation.

Were that to occur, the person’s soul would be safe for eternity, and would be destined to be united with a resurrected body to be with their Saviour forever.

I further believe that we can glean from Scripture that a person who is truly saved will not lose their salvation due to having some pathological brain condition (e.g. advanced Alzheimer’s) such that to external assessment they no longer profess faith. I.e. a doctor examining them would conclude that there is no evidence of any belief at all. Since pathological brain damage does not retrospectively destroy saving faith just because the person is no longer capable of expressing such belief, neither would it do so were that damage to involve the corpus collosum so that they were no longer capable of expressing their faith in a unified fashion. Thus a major issue is whether they had come to the point of regeneration, saving faith, new birth prior to the injury. I.e., if they were a real Christian beforehand. If so, then the fact that one part of their brain were to no longer be able to verify that they believed in God, there is no reason to believe that that injury would affect the person’s eternal destiny.

I hope that helps.

Carl W.


  1. The extent to which that decision is due to God’s election is not at issue here, as from the human perspective, there is at least a seeming decision-making process, and certainly all sides of the election argument would agree that biblically there is also an accountability/responsibility for unbelief. Return to text.
  2. It is of course conceded that pathology can give useful insights into normal brain functioning. Return to text.
  3. This refers to situations where the corpus callosum has been surgically divided, which is sometimes the only option when it comes to controlling overwhelming and recurrent epileptic seizures. Return to text.
  4. In fact, it’s also the lack of content of such assent. Saving faith, according to the Apostle Paul (as Gordon Clark has pointed out) must have the content that Christ, fully man and fully God, died for our sins and rose again. Demons believe in God but not that Christ died for their sins. Return to text.

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