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Richard Swinburne’s recent book, Are We Bodies or Souls? defends the author’s response to his titular question: that human beings are not merely physical beings, but composites of soul and body. In this book, Swinburne presents a rigorous and precise defense of Cartesian substance dualism, taking a rather surprising position for our contemporary age (where, as the author himself notes early on, textbooks on the philosophy of mind tend to begin with a quick refutation of his argument) (p. 9). While physicalism and even property dualism remain fairly standard understandings of the mind and its relation to the body, Cartesian substance dualism seems anachronistic. Therefore, Swinburne must make an especially committed effort to defend his understanding of the mind, what it is, and how it connects/links/interacts with the body.

Over the course of this short book, Swinburne makes use of precisely articulated definitions and thought experiments, in order to make his case. Whether he succeeds or not is another question, though my own thesis research (for which philosophy of mind was the primary topic) allows me to respond more decisively than I would otherwise be able to. In short, I will agree that Swinburne effectively argues that the mind is our primary component. However, I would also say that the very same argument could be used to defend a form of idealism, rather than dualism (indeed, I am not sure that dualism is the only conclusion a reader could arrive at, given Swinburne’s reasons and arguments). 

Swinburne begins his book with a precise definition of the form of dualism he intends to defend, distinguishing it from both physicalist and property dualist understandings of the mind, and its distinction from the body. He also notes the distinction between personhood and existence as a human being, noting that without bodies, our minds might logically continue to exist, even if no longer in “human” form (for our humanity is dependent on an embodied existence). Swinburne concludes that we are, essentially, nonphysical persons, but we can interact with the bodies we are joined to as human beings.

Swinburne uses the question of personal identity to explore the implications and definitions which help him understand his position/point of view. This also allows him to demonstrate his understanding through the use of imaginative, hypothetical thought experiments. For example, Swinburne is both able to argue against physicalism and demonstrate the independent existence of the soul by asking us to imagine a hypothetical brain transplant (suppose the left hemisphere of some person is put into the skull of another person, whose own left hemisphere is then been placed in the first person’s, essentially making two new hole brains by switching half of each) (pp. 54-55). The fact that we cannot say who the original person is, when we consider each of these two human beings (for example: is it the person with the left half, in either case, since that is the location of the language center, Broca’s area?) Logically, the two people with the switched halves of the same two brains cannot both be the same person. Therefore, there must be more to a person than the body. This compels Swinburne to reject the physicalist position as ineffective/insufficient to account for our individual, subjective existence. 

To briefly describe the contents of each chapter: Swinburne spends Chapter 2 of his book discussing philosophical terms which will be put to use in later chapters. Among them are what he calls “mental” and “physical events” (to be discussed in further detail shortly). Swinburne’s discussion of theories of personal identity then follows in Chapter 3, where we see physicalist, property dualist, and substance dualist theories of the mind explained and discussed. Here, Swinburne uses logic to show why only one of these theories is (according to his understanding) coherent. He also tests explanations of identity: whether the continuity of bodily matter, memory, or the persistence of thought can account for the persistence of one’s individual identity through time. It is Swinburne’s conclusion that the simplest theory of identity, that of the mind as a mental substance characterized by its ability to think, is the only satisfactory theory of mind.

Swinburne’s conclusion in Chapter 3 leads to Chapter 4 and 5’s extensive discussion of the nature of the soul, and Swinburne’s argument that it is this non-physical part of each of us that makes us who we are. The importance of the body is an important related question, and so it is discussed as well (could we exist as disembodied souls?). It is worth noting that, like Descartes, Swinburne is only willing to argue that this is “logically possible”; we could argue for its possibility, given that it is our subjective experience that gives us any knowledge we have, about anything at all (our knowledge of bodies and brains is always secondary).

Swinburne’s argument takes an abrupt turn in Chapter 6, in which he acknowledges a relationship between brain states and mental states, but holds to the idea that mental states are indeed prior (for even brain states may rely on memories or react to past experiences). Here Swinburne makes reference to the experiments of scientist Benjamin Libet, whose work I reviewed while writing my thesis (also, again, on the mind-body problem); Libet argued, through data collected through experimentation, that brain states, rather than conscious decisions/states, cause our actions (an impulse arises, and we must then decide to act on it; the argument here is that brain states give rise to our thoughts and decisions). As Swinburne argues that mental events have a causal role in brain events, he naturally rejects Libet’s findings; he claims Libet’s conclusion to be unjustified, as we could also say an earlier brain event may give rise to an intention, which then leads to another brain event, which causes the movement (p. 134).[1]

Chapter 7 is also especially interesting, in light of my interest in evolution and how human nature (and our ability to contemplate the cosmos, compose music, and do philosophy) emerged through its processes. In this chapter, Swinburne argues that it is indeed reasonable to imagine that the soul emerged (or perhaps it is better to say, was actualized) as a result of evolutionary processes, and the development of the vertebrate brain (Swinburne thinks it is reasonable to assume that not only humans, but also most mammals and, indeed, other vertebrates) all possess some degree or kind of soul. The fact that physical stimuli (the senses) affect the brain, and in turn affect the mind, is also acknowledged, though Swinburne makes it clear that the soul of any living thing (human, orangutan, or lizard) exists as a separate substance, independent of the body, and so cannot be reduced to its processes, and does not necessarily depend on it for existence (p. 167). 

One useful idea which Swinburne introduces early on (pp. 22, 26-27) is the distinction between mental and physical events, which he describes as being “private” and “public,” respectively: private mental events have a unique, first-person aspect which each of us is privy to, and the strength of Swinburne’s dualism depends on this fact. For while physicalist theories argue that the neurons of our brains hold the key to our minds and identities, Swinburne, by way of Descartes, argues that human beings cannot be purely physical, as each of us has unique access to our own subjective experiences, thus making them “private mental events,” rather than public, “physical events” (p. 29). An example which Swinburne uses several times throughout the book is of looking at a tree outside the window: the tree’s presence, the movement of its branches in the wind, etc. are public, physical events which any observer close enough can witness and perceive. Meanwhile, my own experience of seeing the tree (my observation of it) would be a private “mental event,” which I alone have privileged access to (someone else’s observation of the same tree would be different, due to position, etc.) (p. 30).

Swinburne concludes from this that we are fundamentally and essentially mental realities (he uses the term “mental substances” to describe us), an idea that follows from Thomas Nagel’s idea that “there is something it is like to be” a mind (and that this “something it is like” is not a physical object or structure, but a subjective experience[2]. A memorable observation from Bertrand Russell, which I read long ago, has helped to clarify Swinburne’s argument (as well as Descartes’) in a memorable, imaginative illustration that quickly came to my mind, while reading Swinburne’s book: 

The usual view would be that by psychology we acquire knowledge of our “minds,” but that the only way to acquire knowledge of our brains is to have them examined by a physiologist, usually after we are dead, which seems somewhat unsatisfactory. I should say that what the physiologist sees when he looks at a brain is part of his own brain, not part of the brain he is examining.[3]

Here, Russell suggests that the person studying the brain is not directly aware of the brain he is studying as a thing in itself, but of its qualia, which exist as his own experience in his own mind/his perception. The fact that it is the private mental experience of seeing a brain, for example, that gives one knowledge of the brain offers us both epistemological and logical reasons to reject materialism, as Swinburne does throughout his book, in light of the priority of first-person experience. It is only through private, mental events that we are able to know/observe public physical events taking place beyond/outside our minds; even our understanding of the brain’s connection to the mind comes to us through this prior experience of the mind. 

Swinburne’s distinction between public and private mental events becomes even clearer with this example. Consider how the firing of a neuron, even if it has a subjective, private, mental aspect (the thoughts, sensations, and experiences associated with it), remains a public, physical event (so long as I have the sophisticated equipment necessary to observe the firing of the neuron). The two are indeed distinct in this way, and public events are always mediated through subjective, private mental events (I see the brain as an object of experience, but do not experience the brain directly; I could observe the neuron firing as an object of experience as well).

Both the brain observed by Bertrand Russell’s physiologist and the tree outside Richard Swinburne’s window are objects of experience, which we know through our senses and perceive in our minds. Even our own brains are objects of experience; if I could somehow see my own brain with a mirror, I would not really be seeing my brain; I would see its image reflected in glass, as an object of experience. And because experience is always prior, we could argue for dualism as Swinburne does, but we could also argue for idealism; perhaps the physical world of public experiences is a property of the experiences of our own minds, rather than a reality separate from them; after all, colours, tastes, smells, etc., exist in the mind, in our perceptions/experiences, rather than things in themselves.

The realization that experience is prior to all knowledge, even our distinction between “mind,” “brain,” or “body,” affirms Swinburne’s argument that the self is the point of origin for all knowledge, and can be imagined independently from our bodily knowledge/experience. That said, the importance of the body remains an important focus of Swinburne’s writing, for he acknowledges the role evolutionary processes played in giving rise to the mind (or soul), even if it may be logically possible for the mind to exist without the body/continue on after death.

On this topic, Thomas Nagel, who also reviewed Swinburne’s book (2020), points out that:

Swinburne has shown that our first-person self-awareness appears to reveal a mental reality independent of anything physical; but we can take this appearance at face value only if we are confident that the mental has no metaphysically necessary connections with the physical that are concealed from the first-person point of view—which is precisely the issue.[4]

However, by appealing to experience, we could (again) also argue for a form of idealism (or a kind of monism based on experience), for our experience is really all we have (as Bertrand Russell’s above example demonstrates).

Upon reviewing the book, one thing I found lacking was a discussion of mind-brain correlations/clear examples in which brain states affect behavior, as I feel that the greatest challenge to Swinburne lies in this area; while Swinburne spends a great deal of time defining terms and arguing for the logic of his arguments, time spent analyzing the findings of more recent and contemporary neuroscience would have been appreciated as well. The Libet experiments were indeed mentioned (noted above), and Swinburne spends three pages discussing the split-brain experiments of Roger Sperry (involving an epilepsy treatment that resulted in the cutting of the corpus callosum, which connects the two hemispheres of the brain). Swinburne offers a number of implications of the divided brain and his idea of the soul (and he finds a way to make each compatible with his own argument), but there are further implications/related procedures and findings he does not discuss (pp. 148-149).

One of these comes from psychologist Michael Gazzaniga, and his observation that there are many separate modules or systems in the brain, one of which acts as a kind of “interpreter” and ascribes a narrative to the objects and events coming in through the senses. Either the relationship of this module to the “I” (could this be the center of one’s “ego” or consciousness?) and how this might resolve the possible dilemma posed by split brains is not discussed; it remains an interesting, missed opportunity.[5]

Finally, another missed opportunity comes as a result of my recent review of Stephen Braude’s Dangerous Pursuits[6] (2020), which includes chapters on the nature of the soul’s possible existence after death (how it might perceive or communicate with others, for example), as well as a brief discussion on the evidence for reincarnation (a topic which Braude has written on extensively elsewhere).[7] At several points, Swinburne takes the time to acknowledge that the soul’s independent existence from a particular body is only logically possible; Braude’s work might offer evidence which might show that the soul’s existence apart from the body is more than just logically possible.

To sum up, Swinburne’s book provides a compelling discussion of a topic that is of special interest to me as a reader. While Swinburne’s presentation of the material is very rigorous and thorough in its presentation; the topic itself (and the brief length of the book) hold the reader’s interest, especially given that Swinburne does not shy away from difficult or challenging questions, and remains determined to defend his dualist position (as unpopular as it may be in our time). He takes time to define all his terms before putting them to use, and his chapters logically follow after one another, as he builds his argument.

Finally, it should be noted that Swinburne also keeps the book focused; I later learned that he converted to Eastern Orthodoxy quite late in life, though his religious convictions do not come into play at any point during this book, even while discussing such topics as the immortality of the soul (indeed, Swinburne keeps a sceptical position regarding these matters, and does not consider any claims/evidence for life after death, as noted already).

In short, this book offers a clear and diligent discussion of an interesting topic, and is well worth the reader’s time/consideration. It offers an important contribution to the literature on philosophy of mind, and has already sparked a number of questions/comments/concerns in my mind, as the last few paragraphs of this review attest.