It seems plausible to many people that we are more than physical bodies: we are also non-physical minds or souls. Our souls are currently embodied and yet have things bodies can’t have such as free will, reason, a conscience, intentional or purposeful mental states, privacy, and unity over time. For many this soul can function independently of matter at times and might even survive the death of the body. This view of the soul and its relation to the body is called dualism.
However, psychologist Stephen Pinker, in his book The Blank Slate (Penguin, 2002), writes:
“When a surgeon sends an electrical current into the brain, the person can have a vivid, lifelike experience. When chemicals seep into the brain, they can alter the person’s perception, mood, personality, and reasoning. When a patch of brain tissue dies, a part of the mind can disappear: a neurological patient may lose the ability to name tools, recognize faces, anticipate the outcome of his behavior, empathize with others, or keep in mind a region of space or of his own body” (p. 41).
Don’t these observations show that we don’t have a soul? Don’t they show our mental states are nothing but physical states of the brain? Well, one who has reasons for the soul’s existence might agree, on the one hand, that the soul’s functioning is closely bound up with the brain’s functioning and, on the other hand, argue that the soul is not just brain functioning. Should the brain change in certain ways then the soul will change in certain ways. But such changes need not imply that the soul doesn’t exist despite the correlations Pinker describes. Indeed, such correlations should be expected. Moreover, mental states that are plausibly not physical – for example, intentional states that think universal concepts which, as universal, can’t be located anywhere in particular – can cause physical changes in the brain. And very few think of arguing that such changes show the brain is just a mind.
But what about cases of extreme brain damage like when a patient goes into a persistent vegetative state never to return as a conscious self? Here we may be more inclined to draw the conclusion that with total brain death there will be a complete cessation of mental functioning as well.
However, American philosopher and founder of modern day psychology William James (1842-1910), in his essay On Human Immortality, writes: “My thesis now is this: that, when we think of the law that thought is a function of the brain, we are not required to think of productive function only; we are entitled also to consider permissive function or transmissive function. And this the ordinary psycho-physiologist leaves out of his account”. This is interesting. We usually think the brain produces thought. But perhaps the brain can also engage in transmissions. He continues: “Admit now that our brains are such thin and half-transparent places in the veil. What will happen? Why, as the white radiance comes through the dome, with all sorts of staining and distortion imprinted on it by the glass, or as the air now comes through my glottis determined and limited in its force and quality of its vibrations by the peculiarities of those vocal chords which form its gate of egress and shape it into my personal voice, even so the genuine matter of reality, the life of souls as it is in its fullness, will break through our several brains into this world in all sorts of restricted forms, and with all the imperfections and queernesses that characterize our finite individualities here below” (see his book The Will to Believe and Other Essays, p. 16). This account paints the picture of our brain as a transmission device through which soul can act and through which “the genuine matter of reality” can break through in an imperfect manner. It would be a matter of a brain-threshold opening. Our brains, to be sure, would be involved in the transmissions; but the brain would not be originating the transmissions. This opens up the possibility that when the brain is damaged the instrument of transmission is harmed not the soul that is transmitting.
This fascinating account raises many questions. If there are indeed souls what are they capable of transmitting? Well, as mentioned above, it is plausible that a brain is simply not the kind of thing that possesses intentionality, thinks universals, reasons with the use of universals, entertain true or false propositions, makes free decisions, has a moral sense, has private mental states, and possesses unity over time. So if souls have these abilities and traits then perhaps they can be conveyed to the brain in ways that allow the body to reveal to other souls justifications for truth claims, freely chosen acts, moral deeds, private thoughts, and, indeed, something about who they, as unified souls, really are. Obviously, many questions can be raised about these controversial claims: how does the transmission take place? Is ‘how’ even the right word here if souls aren’t physical? Can it even take place if the soul is immaterial and the body material? Why don’t transmissions always take place as planned? What are the limits and possibilities of transmission?
And then we would have to face the fact that many people who have had their receivers damaged for a certain amount of time (people in comas from which they awake for example) do not report that they were still conscious and yet unable to communicate. As an epileptic, I myself have had many seizures during which my brain is not in a properly functioning state. And I can report that I had no experience of being conscious yet trapped without a receiver. I was conscious, then had a seizure and blacked out, and then was back. Such testimony doesn’t seem to support the damaged receiver response to brain damage or brain malfunctioning.
So perhaps those who believe in the soul are better off arguing that the soul, due to its close relation with the body, simply cannot actualize its powers when the body is such a compromised state. Should the body recover its powers then the soul will be in a position to actualize its powers as well. Indeed, perhaps our minds, when finally freed from the bodies upon which they are currently dependent, will be more fully actualized then they can possibly be in their embodied state.
Of course for any of these responses on the dualist’s behalf to work we would have to rigorously defend some form of soul/body dualism. For two possible defenses of dualism go here and here. And if theism is included then the above responses may also have more plausibility. For example, if God exists and created the soul then we might have reason to believe the soul will, when finally freed from the body or rejoined with its resurrected body, survive total brain death.
In any case, the effect of brain functions on mental states present dualists with formidable challenges not easily dismissed.