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 dialoguePhaedo isthe 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 themost 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’sTreatise 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 rela