Immortal Souls

Preface

The title of this book is bound to bring to mind two philosophers who are explicitly mentioned only here and there in what follows, but nevertheless loom large in the background throughout. The first is Plato (427-347 B.C.), whose dialogue Phaedo is the great work on the soul and its immortality in the history of Western philosophy. My longtime readers will not be surprised to find that the names of Aristotle (384-322 B.C.) and Thomas Aquinas (1225-1274 A.D.) appear with greater frequency in the book, and that I favor their position where it differs from Plato's. All the same, though he was mistaken on crucial matters of detail, it was Plato who first got right the most important things - that the highest part of human beings is the intellect, that the intellect is incorporeal, that this entails that the soul survives death and is indeed immortal, that it will be rewarded or punished after death, and that all of this can be arrived at by philosophical reasoning independently of any special divine revelation.1 It would be potentially misleading to describe the book's aim as that of vindicating Plato, but I'll risk doing so anyway (albeit with the qualifications one would expect a Thomist to make).2 The truth is dearest, but Plato is still dear to me.

The book is also intended to refute the other thinker its title will evoke, namely David Hume (1711-1776). Hume's essay "On the Immortality of the Soul" is perhaps the most eloquent expression in Western thought of the falsehood that belief in life after death can find no rational support short of a special divine revelation (which, of course, he did not think has ever been given us). Hume's Treatise of Human Nature, from which I borrow my subtitle, is the most influential source of the errors concerning substance, the self, the intellect, and the will that have led modern man radically to misunderstand his own nature. Clearing away this intellectual rubbish is a prerequisite to establishing that Plato was right and Hume wrong.

As my subtitle indicates, the immortality of the soul is far from the only topic to be treated in the pages that follow. Indeed, immortality is addressed only at the end, in the last two chapters. Even the word "soul" will rarely be used until then. That is deliberate. Nothing I have to say in the first ten chapters strictly requires using the word. Also, "soul" has many connotations, not all of them relevant to the topic of a particular chapter, and some of them unfortunate in any case. Rather than repeatedly and needlessly risking misunderstanding and having to make tiresome qualifications, it seemed better to avoid the word until absolutely necessary. This is not the way discussions of the soul usually proceed. But given the word's ambiguity, my view is that the least potentially confusing approach is first to give as thorough an account of human nature as is possible without using the word, and only then to explain where the notion of the soul fits in.

The book is, then, a general treatment of the metaphysics of human nature. It addresses the main philosophical controversies concerning the self and personal identity, the nature of concepts, the relationship between thought and language, the freedom of the will, embodiment, animal intelligence, perceptual experience, innatism versus empiricism, dualism versus materialism, the philosophical implications of neuroscience and computer science, transhumanism, and so on. To be sure, the book is not exhaustive. Certain matters could have been treated in greater depth. For example, much more could be said about the nature and classification of the sensory powers and the appetites. Certain matters are not treated at all. For example, I say nothing about the distinction between the sexes, which is no small part of human nature. (I will treat that at length in a later book.) I had to draw the line somewhere. But the guiding criterion was to address every topic that needed to be addressed in order to defend the sober Aristotelian-Thomistic middle ground position between Cartesianism on the one hand and materialism on the other.3 For that reason, the book's length was unavoidable. Because human nature is complex, the ways we can go, and have gone, wrong about it are multifarious. I have tried to refute the errors that are most prevalent today.

The book's eleven chapters are grouped into four parts. Part I addresses the question "What is mind?" Chapter 1 gives a brief overview of what I will argue is the correct answer, which is that a mind is a self or persisting substance having, as its essential attributes, intellect and will. The next three chapters are then devoted to expounding and defending this answer in depth. Chapter 2 defends the reality and irreducibility of the self; chapter 3 explains the nature of the intellect and its irreducibility to any of the powers we share with other animals; and chapter 4 explains the nature of the will and establishes its freedom.

Part II is devoted to the question "What is body?" Chapter 5 explains the nature of the material world in general and shows that the Aristotelian theory of form and matter not only has not been refuted by modern science, but is if anything vindicated by modern science. Chapter 6 addresses the nature of living matter, specifically, and in particular discusses what it is to be an animal.

The book defends the traditional Aristotelian view that human beings are by nature rational animals, and these first two parts are essentially devoted to explaining what "rationality" and "animality" each amount to. Part III, which is labeled "What is a human being?", refutes the two main modern misconceptions about the relationship between rationality and animality. Chapter 7 is a critique of Cartesian dualism, which radically sunders the human mind from the physical world, making the body something entirely extrinsic and inessential to us. Chapter 8 refutes materialism, establishing that though we are indeed bodily by nature, we are not entirely so, and that the intellect in particular is incorporeal or non-physical. Chapter 9 refutes currently popular claims to the effect that neuroscience has vindicated materialism, and that the mind is a kind of computer program implemented in the hardware of the brain.

The upshot of this part of the book is that a human being is a single psychophysical substance with both corporeal and incorporeal properties and powers. Part IV turns finally to the question "What is the soul?" Chapter 10 argues that, since the intellect is an incorporeal part of a human being, it carries on beyond the death of the body, and that indeed on careful analysis this entails all the main elements of the traditional doctrine of the immortality of the soul. Chapter 11 explains how the position defended in the book relates to the Aristotelian thesis that the soul is the form of the body, and its implications for the origins of the soul and the prospects for its reunion with the body by way of a resurrection of the dead.

Again, many other topics are treated along the way. Many of these are also topics I have addressed in earlier work, such as my book Philosophy of Mind, which first appeared almost twenty years ago.4 They are addressed in greater depth here, and in some cases my views have changed. For example, that earlier book is much too sympathetic to Cartesianism, especially in its treatment of perception. The approach of this book is much more consistently Aristotelian-Thomistic. Having said that, though Aristotle and St. Thomas are by far the greatest influences on my own views, this book is not concerned with exegesis of their work. The claims and arguments I defend in this book are mine, and not always necessarily theirs. If, on some topics, I say something that sounds very much like what they say, that is because I think they were right about it. If, on other topics, I say something that is different from anything they say, or even conflicts with what they say, that is because I think my approach is better. Like other Thomists, I am often accused of following Aquinas too closely, but also of not following him closely enough. In reality, I try only ever to follow an argument wherever it leads.

I also emphasize, again, that this book is concerned only with what philosophy can, all by itself, tell us about its subject. It is not about theology, highly relevant though it is to theology. Many are bound to be surprised at just how much can be established by purely philosophical arguments where the existence and nature of the soul are concerned - just as, as I have shown in my book Five Proofs of the Existence of God, much can be established by purely philosophical arguments where the existence and nature of God are concerned.5 Immortal Souls, like Five Proofs, is intended as a contribution to understanding the praeambula fidei or "preambles of faith" - that is to say, the philosophical premises in light of which it can be rationally established that a special divine revelation really has occurred (though exactly how that can be established is a topic for another time).

In this connection I will acknowledge one final lacuna that I think is unavoidable in a philosophical book with the particular purposes this one has, but has been increasingly palpable to me all the same. I refer to the absence of any treatment of the moral and spiritual ramifications of being a creature with an immortal destiny, yet deeply enmeshed in the material world, with the suffering and liability to death that that entails. The years during...