The authors of this book believe that the time has come for presenting the case for the soul again in an age when it has been largely left out of general consciousness. As they note, the ‘commonsensical’ (ordinary person's) view since ancient times has been that we have souls, not least because most people find it hard to believe that the person perishes at death. In spite of the title, the book attempts two things: in the first half (cc. 1-4) to give a history of thought about the soul; in the second half (cc. 5-8) to propose the authors' own brand of dualism, which they call ‘non-Cartesian dualism’ in a sustained argument against contemporary materialist theories of the mind and human beings (Sosa, Kim, Honderich, Dennett, Armstrong and others). Non-Cartesian dualism seeks to overcome the difficulty raised by Descartes's theory for the interaction of body and soul.
The reviews of the main contributors to thought on the soul in the early chapters bring to light many interesting points, but sometimes miss important points. The authors would have strengthened their own case if they had given more of Plato's arguments for the immateriality of the human soul (the senses are bodily like the things they perceive, and the soul is immaterial like the Ideas which it knows). They were clearly happiest in writing about St Augustine and are particularly informative about his arguments for the immateriality of the soul, which they focus on self-consciousness. Original sin remained a difficulty for St Augustine when it came to the origin of the soul, for how do we inherit guilt from Adam if our soul is not propagated by generation? In the end, the authors quote Augustine as saying that he did not think the question mattered and seem to rest content with this. But surely the origin of the soul is crucial for showing that the soul is immortal, as Aquinas clearly perceived (ST 1a 118,2: if it comes from matter it cannot be immaterial or immortal).
I felt that the authors lacked sympathy for Aquinas, were too ready to find fault with him and were not entirely fair to him, partly because of misunderstanding him on some points. Aquinas does not say that the soul moves the body through the heart in humans, only in animals. They rather miss the decisive point that the soul gives existence to the body and thus can remain distinct when no longer individuated by a body after death. They also fail to take sufficient note of Aquinas's idea that the human soul is a subsistent form. This was the crucial development by Aquinas of Aristotle's idea of the soul as the form of a human being, which allowed the soul to be immortal (a difficulty of Aristotle's theory). Nor does Aquinas explicitly say that the separated soul is not my ‘I’ but is not a person because it does not have the complete nature of a human being. The authors clearly prefer the view of C.S. Lewis and Richard Neuhaus that my soul is my ‘I’.
The reader will find questions raised by Locke's equation of the person with consciousness neatly answered in the sections on Joseph Butler and Thomas Reid. The historical part of the book, however, only takes us up to Kant. Something could have been said about the revival of dualism among British philosophers like H.D. Lewis in the second half of the 20th century. And, on the Aristotelian/Thomist side, Peter Geach deserved a mention, especially as the authors use his idea of ‘basic activities’ (unacknowledged). Although Wittgenstein may not seem to support the soul, he said some valuable things about thinking and understanding which point to the immateriality of the mind and merit attention. His remarks about dualism at the end of the Blue Book should also have been taken into account.
The second half of the book provides a trenchant criticism of materialist views of the mind and, in particular, of various forms of identity-theory (that thoughts can be correlated with events and processes in the brain). This part seems to be written in a quite different style, more typical of much academic philosophical writing today, with long sentences (only three whole sentences on p. 164). Although the authors refer throughout to ‘we believe’, it would have been helpful to know who wrote which parts, as is common in many books of dual authorship. The strength of their argument in this second part is double pronged: first, our behaviour is teleological: the beginning of our actions is choosing a goal and this cannot be explained physically because it is undetermined if we are free. Second, dualism allows for interaction between body and soul because there clearly is more to our actions than neuro-scientists can explain. I found the argument from teleology impressive.
In their conclusion, the authors opine that any discussion of the soul will lead to discussion about the origin of the world. Thus one's view of the soul is affected by one's view of the world. How can the rational arise from the irrational? As they note that the main reason for the denial of the soul by materialists today is their determination to exclude dualism, it seems a little strange that the authors should turn to dualism as their preferred view of the soul rather than give more attention to views that more obviously preserve the unity of body and soul.
The main strength of this book is the case that it presents against materialism. It also interestingly focusses on arguments against the soul from natural science: for instance, if the soul is the source of action in moving the body, is there not an input of energy that violates the principle of the conservation of energy? But the authors rather assume the existence of the soul; this needed to be argued for much more, especially today, when it is thought that we do not need the soul to explain life. Consideration of the question of the origin of the soul is indispensable if we want to show that human beings are not merely products of evolution (a favourite theme of Benedict XVI). The authors talk too generally about ‘interaction’ between body and the soul without focussing on specific activities of the mind, like forming concepts, thinking, understanding. They would then have been in a better position to show that the human soul is immortal because immaterial, but they devote surprisingly little space directly to immortality, very briefly on p. 211. There is clearly much work still to be done in arguing for the soul in a way that preserves the unity of the human person and immortality of the soul.
