In the opening of the book, the authors lay their cards on the table. They briefly explain the difference between the opposing ideas of materialism and substance dualism and then state, “our aim is to set before you a brief history of the idea that we are embodied souls.” Their goal is present a counterclaim to philosophers like Jaegwon Kim who states “each of us is a soul, my soul is the thing that I am”, and Owen Flanagan who says, “the mind or the soul is the brain.”
The Soul in Greek thought
In the first chapter, the authors trace the concept of the soul or psyche within Greek thought as it is found specifically in the Greek philosopher Plato. In examining Plato, they show Plato taught the immortality of the soul along with the concept of reincarnation. For Plato, the soul pre-existed before being embodied and is not tied to any particular body. The body was also viewed as a prison of the soul, and the desire was ultimately to escape the imprisonment of the body. Ultimately, the soul is set in contrast to the body because it is; indestructible, immortal and imperishable. Next, the authors examine Plato’s student Aristotle. For Aristotle, a soul requires a body for life, and each soul is specifically tied to its identity with its body.
The Soul in Medieval Christian thought
In the second chapter, the authors move on to examine the teaching of Augustine and Saint Thomas Aquinas. Concerning Augustine, the authors explain that we see the affirmation of Plato and the rejection of Aristotle. Augustine is a substance dualist and also taught the immortality of the soul. For Augustine, the soul is immortal because it is a simple thing and is indivisible. The soul is also a rational thing and cannot cease to exist. While Augustine follows Plato in the form of substance dualism, Aquinas taught that the soul was immaterial by nature. Here Aquinas continues the concept of dualism but wants to move the soul from the category of substance to the immaterial. Aquinas goes on to argue that a soul is specific to its individual body and because it is not corporeal, it is also indivisible. Finally, he declares that a soul can subsist without the body and is immortal by nature. For Aquinas, the soul is created at birth by God. With this shift in thought, the new question in philosophy arises, how does an immaterial soul interact with a material body?
The Soul in Continental thought
Chapter three is primarily concerned with the philosophical teaching of Descartes. The authors show how some of what Descartes writes and has been attributed to him as original thought, can be traced back to Augustine. The authors explain that for Descartes, “death is the irreversible breakdown of the bodily machine, and the soul leaves the body because of its brokenness.” Descartes also follows the teaching of Aquinas that the soul is immaterial and distinct from the body; in fact, he thinks that the soul itself is not located in space, period. Descartes is comfortable conceding that the casual interaction between an immaterial soul and a material body is a mystery that cannot be solved. He does hypothesise through scientific means that this interaction may occur primarily through the pineal gland. In Descartes writing, he concludes three things about the soul; that the soul must be a created thing, the soul must be independent of the body and can survive death, and as a result, the soul must be immortal.
The Soul in Locke, Butler, Reid, Hume and Kant
In the fourth chapter of the book, the authors explore what they describe as a shift in the philosophy of the soul. Where the soul ceased to be and had become the mind instead. These philosophers begin to address the continuity of identity over time regardless of the changing shape of the body. For Locke, this meant that a person’s identity was the equivalent of their consciousness. This idea then tied one’s soul to the sum of their memories. Does the question then become if I begin to lose my memory does my identity also change? Some philosophers argued against this train of thought proposing that identity remains the same regardless of what one can remember. Other hypothetical situations are proposed, such as questioning if a person is still the same ‘I’ if they were to lose a limb. What is interesting is that these questions often revolve around a limb such as a hand or a leg but never consider the fact that a person cannot continue to exist without their brain and how that might correlate to consciousness and the soul. Other philosophers in the chapter go as far as to make statements such as “as simple immaterial substances, souls are not part of the natural world.” This thought seems to do an injustice to the creation account found in Genesis that we are physical material beings formed by our Creator. It appears to subdivide humanity into that which is natural, namely the body, and that which is unnatural, the soul.
The problem of the Soul-Body Casual Interaction
The fifth chapter in the book explores the question of how the body and the soul interact with one another. Also, the authors explore how philosophical ideas are shaped and differ depending on whether or not one believes the soul to be a substance that takes up space or something immaterial. If the philosopher takes the Cartesian view of the soul that it is immaterial, then they will struggle to explain how an immaterial soul interacts with a material body.
On the other hand, if one believes the soul is material or substantive in nature, then the question arises, where is the soul spatially located? Is the soul located in the brain, or is it the form of the entire body, and if so, do you lose a part of your soul if you were to lose a limb? If one takes a Cartesian view of the soul, the question arises, why is one person’s soul paired with their particular body and not another person’s body? Also, if souls are not spatially located what is to keep one person’s soul from interacting with and influencing someone else’s body? We might also ask is it even possible for a non-spatial object to exist at all? The laws of physics seem to dictate that for the law of cause and effect to be true, the soul would need to be spatially located.
On the other hand, a Cartesian dualist might argue that we lack the full knowledge of what none spatial souls are capable of doing and not doing. Here the philosopher must retreat to mystery. While these may be interesting questions to reflect on, dualism in either camp, the substance dualist or Cartesian dualist seem to pose more unanswerable questions that in the end retreating to the unknown. It seems instead that a much more straightforward answer would be to go the physicalist route and do away with these hypothetical questions altogether.
The Soul and Contemporary Science
In chapter six, the authors move on to the intersection of science and a dualist anthropological approach to the soul. The challenge they suggest is for the dualist to reconcile their beliefs with modern scientific discovery and specifically as they indicate the mapping of the regions of the brain that correlate to human action. Their argument ultimately resides in the idea that while there is a casual interaction between the soul and the brain, that does not demand that the brain is the soul. The dualist can propose that the soul and the brain interact during the time frame in which the soul is attached to the body during biological life. They state that the opposing view is that “science makes belief in the soul unreasonable because it makes impossible any appeal to the casual interaction between a soul and its physical body.” In the final section of the chapter, the authors explore how soul-body casual interaction seems to conflict with the scientific idea of the conservation of energy. The scientific argument is that the body is a closed system in which a soul would need to introduce energy into the brain to cause a reaction, and this would violate the conservation of energy of a closed system. The authors conclude that this may mean that the mind and or body is not a closed system, and the soul does introduce energy into the brain when causation occurs.
Contemporary Challenges to the Soul
In chapter seven, the authors attempt to respond to seven contemporary challenges to a dualist philosophy of humanity. First, they address the idea that dualism is essentially proposing humanity to be a ghost that lives inside of the machine, which is the body. Next, they address what is called the private language argument. Then, they go on to explore Ockham’s Razor and the issue of personal identity. The fourth challenge they discuss is the argument from neural dependence, and they address several arguments for personal identity. Finally, the authors address very shorty a proposed argument from evolution.
Thoughts on the Future of the Soul
In the final short chapter, the authors give their views and comments on a few areas of study they feel will be necessary for the continued research of the soul-body debate. Ultimately, because they conclude that dualism is the Christian view, they seem to think that a materialist approach to the topic is not one that can also support a Christian worldview. What appeared to be lacking and incongruent with this chapter is the reminder that the Christian belief and hope is in the bodily resurrection that is physical and material.
In summary, this brief history of the soul has traced philosophical thought about the human body and the idea of a material and immaterial soul through historical visiting several influential thinkers along the way. It is important that the reader is reminded that this book is written from a philosophical standpoint rather than a theological one. In chapter two, the writers give one page of support to their view that “Hebrew and Christian sources …testify to the belief in the reality of an afterlife for individual persons.” They state that “this is often described in terms of bodily resurrection, but there is also an affirmation that, at death and prior to the resurrection, the soul (or the person) is with God.” Their working assumption then is that scripture has already validated their claim of dualistic anthropology. For further study and proof of this, they point the reader to John Cooper’s book Body, Soul and Life Everlasting; Biblical Anthropology and the Monism-Dualism Debate. For more on that book see my article here: Book Review: Body, Soul and Life Everlasting; Biblical Anthropology and the Monism-Dualism Debate
I found this book useful in articulating and summarising some of the important dualist thinkers and how they have approached the body-soul problem. I did, however, find it problematic that they assumed the Bible to prove their point without much discussion on the Biblical texts. It is hard to be disappointed, however, because that is not the purpose of the book. I would recommend this book as a way to get a handle on some of the basic philosophical thought of important philosophers such as; Plato, Aristotle, Augustine, Aquinas, Descartes, Locke and several others. Both materialist and dualist struggle to fully be able to articulate or explain human consciousness. It seems though that the dualist view of the body/soul becomes very problematic to defend from a Cartesian standpoint because of the issues of causation. On the other hand, a substance dualism approach also struggles to articulate a spatial location for the soul.