By David Kyle Johnson, Ph.D., King’s College
“Stomp your foot once in objection to science because it doesn’t tell you what you want to hear and the entire foundation upon which almost all of our knowledge is based will come crumbling down.“
Recently, I was asked by Richard Doupe, the academic director of Berkhamsted School, if he could use my Think article “Do Souls Exist” for their philosophy of religion classes—and, more importantly, if I would field questions from the students after they had read it.
The Berkhamsted School is a school on the outskirts of London—what we in America would call a private middle/high school. Established in the 16th century, it (and its 2000 students) has an outstanding reputation for academic excellence and most of their students end up going to the top 30 universities in the UK. It was no surprise, then, that they asked some excellent questions.
I spent enough time answering them that I thought I would share their questions and my answers, in the hopes that others with similar questions might benefit. Enjoy!
This article first appeared in Professor David Kyle Johnson’s regular column on Psychology Today
Question 1: You place a great deal of store on neuro-science and physics, yet we have just read an article by Raymond Tallis, based on his ‘Aping Humanity’, that raises doubts about this. Why are you so confident in science?
This is a great question. I’m not sure which article you read, but I am somewhat familiar with Tallis’ arguments. To my knowledge, he does not doubt science’s ability to tell us about the world. Now others do make this argument; when presented with scientific evidence against a view they cherish (like their belief in the existence of the soul), they will question science’s ability to tell us about the thing in question (or anything for that matter) – or the objector will claim that I am putting “faith” in science (instead of whatever the objector has chosen to place faith in). But there are multiple things wrong with this line of reasoning.
Learn More: Do Our Souls Make Us Free?
First of all, science is not based on faith; the primary assumption in science is that one should not take anything on faith but instead should base one’s beliefs on evidence and argument—which is the opposite of taking something on faith. Of course, one might suggest that scientists have to take this “primary assumption” on faith—but even if that is true, doing so is a completely different kind of faith than the objector has in mind.
It is certainly not the kind of faith required by the belief systems of those who posit this objection. In other words, believing “by faith” that it is good to proportion one’s belief to the evidence is completely different than believing the soul by faith. [For more on this, see the 17th chapter of my book Inception and Philosophy: Because It’s Never Just a Dream entitled “Taking a Leap of Faith: A How-to Guide”. (You can download it for free here.)
…science has proven to be the most reliable guide to truth—most certainly, the most reliable guide to discovering the way the world is—that humankind has ever conceived.
It’s also not to say that science can discover all truth; moral truths (if they exist), for instance, are outside the grasp of science.) The evidence for this, of course, is all around you in every piece oftechnology that makes your life so much easier than it otherwise would be; almost all of it was made possible only because science successfully discovered the way the world is and works. If we really were to doubt what science tells us because it is not “certain,” then in reality we should be agnostic about everything – proclaiming that we don’t even know whether the world is real or whether we even exist.
In short, if you can’t be confident in the findings of science, you can be confident in anything.
What is usually ironic about people who pose the “anti-science” objection is that when it comes to anything else, they do trust science – they trust science (meteorology) to warn them about hurricanes and tornados, they trust science (medical science and biology) to cure and prevent their diseases and to heal their injuries, and they trust science (engineers and physicists) to build their buildings and bridges.
If someone stole their wallet, they would not accept an explanation like “a ghost took it”– but instead would appeal to the criteria of adequacy (which they may or may not know are the criteria for scientific explanation) to figure out who actually took their wallet so they could get it back. In short, any “can we really trust science?” objection to arguments I have presented against the soul are on very thin ice; stomp your foot once in objection to science because it doesn’t tell you what you want to hear and the entire foundation upon which almost all of our knowledge is based will come crumbling down.
But, again, Tallis is not making this objection. Tallis is actually an atheist who, like me, objects to the soul hypothesis. What I have used the neuroscience for is to show that the primary assumption of the soul hypothesis – that mental activity is separate and separable from the brain (i.e., that mental activity is not dependent upon the brain)—is false. Instead, neuroscience shows us that the existence of the mental is dependent upon the existence of the brain; without the brain, the mental cannot exist. This is something that Tallis agrees with, so in no way would Tallis object to my argument against the soul hypothesis.
What Tallis is objecting to is a separate suggestion made by some neuroscientists, and some philosophers of mind that: “the brain is numerically identical to the mind.” Numerical identity expresses the strictest form of identity. X is numerically identical to Y means that X and Y are the same object.
Clark Kent is numerically identical to Superman; John Smith is numerically identical to “The Doctor.” In claiming that the brain is numerically identical to the mind, one is claiming that the brain and mind literally are the same object – one in the same thing.
In philosophy of mind, this thesis is known as Identity Theory. Some have concluded from the fact that the mental is dependent upon the brain that the mental is identical to the brain. Tallis argues that this is not correct—that this is a fallacious bit of reasoning. And he is correct; dependence does not entail identity. It could be that they are identical, but even if that is true, that fact does not follow from their dependence.
Dependence is a necessary but not sufficient condition for identity. If they are identical they are dependent, but the fact of their dependence does not guarantee their identity. (For example, our local rock radio station is 97.9X . The 97.9X radio signal would not exist without their radio tower, yet the signal and the tower are not one in the same thing.)
So Tallis is not disagreeing with what the science shows—that the mind is dependent upon the brain. But he is denying that the science shows that mind and brain are identical. Contrary to what many claim, all it shows is their dependence.
Tallis I believe goes on to make a number of other arguments against identity theory that are common in philosophy of mind. For example, the mental seems to have properties that no physical thing (like the brain) has: like about-ness, or intentionality. A thought can be about something; but it seems that a physical object cannot be about something.
Or think of what it is like to have an emotion; that property seems to be something that no physical thing has. What’s more, the brain has physical properties that no mental thing has; for example, all brain events have a location, but do emotions have a location? It seems not. If brain and mind are identical (if they are one and the same object), then they would have to have all the same properties – but it seems they do not. Thus it seems they are not identical. (Identity theorists do have objections to this line of reasoning—but I don’t have room to get into all that.)
Learn More: The History of The Soul
So exactly how do we make sense of the relationship between the mind and the brain? We know it is one of dependence, but (for example) how exactly does the brain produce mental activity? How can something without mental properties (like the brain) produce something with mental properties (like the mind)? This is called the hard problem of consciousness, and it’s one of the big questions in philosophy.
And to simply interject the soul as an explanation for something we have yet to explain (like consciousness) is to actually present no explanation at all
Keep in mind, however, that the fact that we have yet to answer this question does not add any legitimacy to the soul hypothesis. Even though we don’t know how the brain produces the mind, neuroscience still shows us that it does, just like it shows us that the mind is dependent upon the brain (contrary to the claims of the soul hypothesis).
So we still know the soul hypothesis is false. And to simply interject the soul as an explanation for something we have yet to explain (like consciousness) is to actually present no explanation at all; it’s like wondering how Penn & Teller do their bullet catch trick and simply saying “they have magic powers.” That’s not an explanation; that’s just another way of saying that you don’t have one.
It is not philosophically acceptable (or rational) to simply stick in your favorite supernatural explanation for something that has yet to be explained, and claim that as evidence for it.
Question 2: Just because Phineas Gage’s personality changed due to his accident does not mean there is no metaphysical soul – the soul might not be able to interact with the world due to the damage to his mind. Is this not a credible answer?
This is a very common objection – if, you are asking what I think you’re asking. A slight typo needs to be corrected, I believe. I think you meant to say “the soul might not be able to interact with the world [i.e., his body] due to the damage to [his brain]” … not “his mind.” Your idea, I think, is this: perhaps damage to the brain does not actually damage, affect or change the mind/soul.
If it’s a separate entity, that couldn’t happen. Perhaps the brain is merely a “relay station,” that receives input from the soul (like an antenna) and communicates that input to the body. Damage to the brain damages the antenna, keeping the soul from successfully communicating its intentions to the body, and thus preventing it from being able to make the body behave as it wishes. So the mind is still there, undamaged; it’s just that its ability to communicate or control the body has been hindered.
Again, this is a common objection, but it is not a very good one. It has all the makings of an “ad hoc excuse” – and unfalsifiable hypothesis to save one’s cherished belief from the evidence. The soul hypothesis initially predicted that brain damage should not be able to affect personality; when it becomes obvious that it does, the soul hypothesis is “then tweaked” to account for the disconfirming evidence. The fact that such “ad hoc moves” are irrational is something I cover in critical thinking 101. See: http://rationalwiki.org/wiki/Ad_hoc
What’s more, this commits us to an extremely ridiculous view. According to this view, the brain damage is responsible for “misinterpreting” the signal sent from the soul; but the misinterpretations are so specific as to defy probability or explanation.
For example, my paternal grandfather had Alzheimer’s, which damages the brain extensively. On this view however, it could not have damaged his mind. So it’s not the case that he forgot large portions of his life. When someone asked him about it, he actually did remember – it’s just that when his soul sent the signal to say “I remember” his brain misinterpreted that signal in the very specific way it needed to say “I forgot” instead. Or…he actually knew that my niece was not my sister, it just so happened that his brain damage was just such that when his mind sent the signal to say “Kanon,” his brain interpreted that in the specific way it needed to say “Mendi” instead.
And Phineas Gage was still a polite and genteel person, it’s just that his brain was damaged “just so” so that when his mind decided to do polite and genteel things, it instead sent a signal to swear and molest women.
Phineas Gage was still a polite and genteel person, it’s just that his brain was damaged “just so” so that when his mind decided to do polite and genteel things, it instead sent a signal to swear and molest women.
If the brain really just is an antenna, damage to it would either prevent it from interpreting the signal all together (so that upon the soul deciding to do something, the body would not do anything) or would interpret the signal in random ways – a decision to say “Kanon,” for example, could just as likely be interpreted as a decision to get up and do a gig, or go eat a hamburger, as it would be to say “Mendi.”
Learn More: What Preserves Personal Identity?
In short, this “alternate explanation” for the behaviour of brain-damaged patients is just “too convenient” to be rational. Sure it’s possible, but it’s not likely—and the mere fact that something is possible is not a good reason to think that it is true. The best explanation for why brain damage causes the behaviour it does is because of the neurological explanations explicated in the paper—because the mind is dependent upon the brain, and the damage to one damages the other.
Perhaps it is worth noting that your typo itself – which confused “the mind” with “the brain” demonstrates how closely we know they are related. Often we equate the mind with the brain because we know that the mind is directly dependent upon the brain for existence.
Question 3: Do you think there might be a “third way” to explain our emotion/feelings etc. other than just the Soul-hypothesis or materialism?
No I don’t think so; the option you suggest really is between “one substance (material)” and “two substances (material and soul)”. What would the next option be? Zero substances? That can’t be right. Three substances? How is that going to help? That will just make things more complicated.
However, it might be useful to keep in mind, as I pointed out in the first question, that materialism comes in many different varieties – one of them may be the “third way” you are looking for. For example, one version of materialism – probably the one that you had in mind initially – is called Identity Theory, which suggests that the mind and the brain are numerically identical. But this is only one of many materialist views.
Others philosophers suggest that, while the mind is certainly dependent upon the brain for its existence, it is not identical to the brain. (After all, dependence does not entail identity—as I discussed above.). Some suggest that the mind is an “emergent property” of the brain – something that emerges when neural interactions are complicated enough.
Some suggest this emergent property is “reducible” to the brain (all its properties can be fully explained by the interactions of neurons); others suggest that it is irreducible. Some suggest that the emergent mind has causal powers – that it can causally affect what happens in the brain. Others, called epiphenomenalists, suggest that the mind exists, but does not have any causal powers. It’s merely “along for the ride.” Property dualists suggest that there is only one kind of substance – matter – so they are materialist.
But they suggest that matter has two kinds of properties, physical properties (like mass and location) and mental properties (like the “qualia” of experiences). Still others, called eliminativists, suggest that the mind does not exist at all – the notion that it does is just a product of “folk psychology.”
So as you can see, although, in one sense, there really are only two options dualism (soul talk) and materialism – materialism comes in so many different varieties, that in a very important sense there are many more than just two options for giving an account of our minds (e.g., our emotions or feelings).
If you want to know more about the different varieties of materialism, I talk extensively about them in my The Great Courses course “Exploring Metaphysics” that I mentioned above.
Question 4: Those who believe the soul-hypothesis argue that a non-physical entity (the soul) drives a physical entity (the body). How do they make this argument?
…the desk in front of you seems to your everyday experience to be solid, but science has revealed that it is actually mostly empty space. Our intuitions are just not that reliable
To my knowledge, there are no arguments to this specific conclusion. Instead, intuition or “how things seem” are used to motivate others to accept this view. When you consider your everyday experience (look out upon the horizon), it seems that the world is flat; In the same way that, when you consider your everyday experience, it might seem that the mind is not material and reaches out from beyond the physical world and causes your body to move.
Again, there are no arguments that this happens – it just “seems to be true.” But just like they did for our notion that the world is flat, philosophy and science have cast this “every day intuition” into serious doubt. This is quite common – our everyday experience is not all that reliable, and very often things are different from how they intuitively seem. (Another great example, the desk in front of you seems to your everyday experience to be solid, but science has revealed that it is actually mostly empty space. Our intuitions are just not that reliable.)
Most arguments for dualism (the soul hypothesis) take the form of trying to refute arguments for materialism. The idea is that if materialism can be refuted, dualism is the default position. I suppose, if there are only two options (as I suggested above), this is true—but none of these arguments have been successful. Evidence for this can be found in the fact that only 27% of philosophers even learn towards a non-physical view of the mind.
What’s more, many such arguments take the form of suggesting that the mind and brain can’t be identical because they have different properties. (I talked about this argument in response to the first question.) But as we saw in my response to the last question, there are many varieties of materialism that deny identity and would admit that they have different properties. So such arguments fall dramatically short as arguments for dualism; at best, they can only refute one particular kind of materialism.
Now there have been some attempts to account for how the nonphysical mind could interact or direct the physical body. Again, these are not arguments that it does happen – just attempted explanations for how it could happen.
But these arguments are also usually considered unsatisfactory. For example, Descartes suggested that the brain interacts with the body through the pineal gland. (http://plato.stanford.edu/entries/pineal-gland/) If I recall correctly, this was because it is the only gland in the brain of which there is only one—and, at the time, we didn’t know what it was for. (But read the article for more info.)
But not only do we now know what it is for – it helps regulate sleep – but such an explanation in no way answers the classic problem of “downward causation” that I mentioned in the paper. This explanation just “backs up the problem,” leaving us to wonder how a nonphysical entity could affect the pineal gland, instead of wondering how it could affect the brain. In short, substituting one physical object for another does nothing to solve the problem of how the nonphysical could causally interact with the physical.
Others have suggested that the soul does not cause physical objects – like the atoms in your brain – to move, but simply “redirects their movement.” They think this gets them out of the problems of violating the conservation laws I mentioned in the paper. It does not – even redirection requires a transfer of energy, so if the soul is redirecting anything physical, it is violating those laws.
Question 5: Have there been other cases, similar to that of Phineas Gage, where the frontal cortex has been damaged but without serious personality change? If so, would this strengthen the Soul-hypothesis argument?
What we would need, to make the soul hypothesis rational, is a wealth of repeated well-controlled verified experiments showing that mental activity is not dependent upon brain activity
There are no such cases that I know of—especially the frontal cortex. There may be cases of other kinds of brain damage that did not have a significant effect on someone’s behaviour. Such cases likely reveal “nonvital” portions of our brain.
Perhaps, very localized minimal damage to a specific location in the frontal cortex might have no observable effect – but again, this would just reveal a “nonvital” portion of the cortex. I believe there are also other cases where the negative effects ultimately went away because the brain was able to repair or “rewire” to compensate. But to my knowledge, there are no cases of significant damage to the frontal cortex without significant behavioural impairment.
Now if there were – let’s say someone’s whole forebrain was completely pulverized and they suffered no ill effects at all – that might be reason to reconsider the soul hypothesis. But one such case is not going to justify rejecting materialism in favour of dualism. Case studies alone cannot establish the effectiveness of a treatment, much less the truth of a hypothesis. (That is why I did not rely merely on the case of Phineas Gage, but used it to introduce the wealth of knowledge established by neuroscience which calls the soul hypothesis into doubt. I also coupled it with a host of other philosophical objections that have nothing to do with neuroscience.)
What we would need, to make the soul hypothesis rational, is a wealth of repeated well-controlled verified experiments showing that mental activity is not dependent upon brain activity. A single case of someone’s cortex being pulverized with not metal impairment would be a reason to do those experiments, but by itself would not prove the soul hypothesis. After all, such a case just might prove that we were wrong about what functions certain parts of the brain have—or how malleable the brain can be. Given the amount of evidence that the dependence hypothesis already has, proving it wrong by experience is a very tall order—not impossible, but almost as hard as proving that the world isn’t round.
As a side note, it’s important to be initially skeptical of medical reports that contradict established medical knowledge. (If it sounds impossible, it probably didn’t actually happen.) That’s not to say that we should always accept what is already established no matter what—we could never learn that we were wrong or advance in our knowledge if we only ever accepted what is coherent with what we think we already know.
But the threshold of evidence for claims that contradict knowledge is quite high; if all you have is one report contrary to common knowledge—like one that suggests a patient suffered extensive frontal cortex damage that had no mental impairment – that is good reason to doubt that that report is accurate. The internet is filled with medical pseudoscience – e.g., people waking up with new language abilities after injuries. Minimal research, however, will reveal that such stories are a farce. I would be equally skeptical of any story you came across that suggested that frontal lobe damage and was not accompanied by mental impairment.
Question 6: It is clear that you do not believe in a soul; but which of the arguments against the soul-hypothesis do you think is the most convincing and why?
It’s important to realize that the goal of the article was merely to make the reader aware of the arguments and reasons that many philosophers doubt the existence of the soul; I could be a believer in the soul and still have written the paper. I actually wrote the paper to be used in a class where we talk about the soul hypothesis because I wanted them to read a paper that articulated the reasons why philosophers and scientists doubt the soul hypothesis, but I could not find one that put all the arguments in one place.
As to the argument that I find most convincing – I’d have to say that the mere fact that the arguments for the existence of the soul fail is reason enough to doubt the soul’s existence.
But you are correct in assuming that I do not believe in the soul myself. As to the argument that I find most convincing – I’d have to say that the mere fact that the arguments for the existence of the soul fail is reason enough to doubt the soul’s existence. As I said in the paper, the burden of proof is on the believer, so the failure of the arguments for the soul is enough to justify doubt.
But I would say the one that is most convincing– that has convinced the most people – is the evidence from neuroscience. The soul hypothesis has us assuming that our mentality is independent – if we just try hard enough or want to, we can do whatever we want. Realizing Phineas Gage was forced by his brain damage to have a different personality falsifies that assumption.
If his mentality really was separate, he could have just decided to be a nice person. Or consider cases of paralysis denial, where patients have strokes in the right hemisphere that paralyze the left side of their body, and yet they will deny the paralysis – even engaging in behaviour that requires two hands, sometimes at their own peril.
When they fail they will even insist that they successfully performed the action, or go so far as to concoct excuses for why they could but didn’t. (See Chapter 7 of Ramachandran’s Phantoms in the Brain.) If our mentality was something separable from our brain, these people could simply realize their paralysis and admit it; instead – and only stranger still – it seems the only way to get them to admit it (and this only temporary) is to drop warm water inside one of their ears. (No joke! Check out the book. It’s only a case study, but it’s really weird.) This is all perfectly explicable on materialism; it makes no sense on the soul hypothesis.
Question 7: Is your account of freedom persuasive if we have no immaterial mind/soul?
I mentioned briefly in the paper the threat to free will posed by the fact that the soul hypothesis is false. Materialism does make it difficult to account for free will, but it is not the only thing. As I argued in my paper “God, fatalism and temporal ontology,” God’s foreknowledge, and in fact the laws of logic themselves, entail that the future already exists in a way that precludes alternate possibilities. There is only one way the future could turn out because there is already a set of true propositions that accurately describes the future.
The future already exists because it must serve as a truthmaker for future tense propositions – propositions about the future. Worse still, this temporal ontology – this view that the future already exists – is entailed by general and special relativity. (Again, I go into more detail regarding this in “Exploring Metaphysics”.) It’s also inescapable if you think that God exists and has foreknowledge.
So, in short, you don’t have to be a materialist to have doubts about your ability to do otherwise (to behave other than you will). And if you think that free will requires the ability to “do otherwise” – if you think you can’t act freely unless, when you make a decision as to whether to do A or ~A, it really is possible for you to do either—then your inability to do otherwise entails that you are not free. Even if you assume the soul hypothesis, free will is difficult to defend.
Some however don’t think that free will requires alternate possibilities; these people are called “compatiblists” and think that we are morally responsible for what we do, and thus do it freely, as long as our actions flow out of some part of us
Some however don’t think that free will requires alternate possibilities; these people are called “compatiblists” and think that we are morally responsible for what we do, and thus do it freely, as long as our actions flow out of some part of us – some part of our psychology like a rational deliberation or our “second order wants and desires.” In short (and in line with Markosian “compatibilist agent causation”), if that’s true, then even if materialism is true we are still free. Why? Because I can still be the cause of my actions, even if I don’t have a soul. If so, then the soul hypothesis being false does nothing to threaten free will.
So in summary, free will is difficult to account for. If it requires alternate possibilities, then likely we are not free regardless of whether the soul exists or not. Even if the soul does exist, there are many reasons to think that there is only one possible future, and thus that we are not free.
If free will does not require alternate possibilities however, then the existence of the soul does nothing to bolster the notion that we have free will; we can still be the cause of our actions, and thus be free in a compatiblist sense, even if the soul hypothesis is false (and we can’t do otherwise).
I hope that all helps, and that you were enlightened about something important.