Edward Feser’s Five Proofs of the Existence of God* (San Francisco: Ignatius Press, 2017) has been out for a few weeks now, though I received my copy, ordered in June, just a few days ago. The book commands serious reading and serious reading is slow reading. I am therefore quite early on in my reading and reflecting upon the book. Even so, I do have some comments on the book I would like to offer, the first of which is that the book is extraordinarily well organized: Feser tells you in advance and clearly what he will do, does it, and then, periodically and helpfully, sums up where the argument stands, telling you what he thinks the book has done.
Second, the book spells out a version of classical Aristotelian metaphysics or, more specifically, of the natural theology that the Aristotelian tradition thinks that that metaphysics includes. This metaphysics adheres to a resolute rationalism, according to which the real is intrinsically rational or, better, intelligible. It upholds, then, among other principles, the principle of non-contradiction, according to which no being can both be and not be, in any one respect and at any one time, and the principle of excluded middle, according to which all beings must either be or not be, in any one respect and at any one time.
In Five Proofs, to be sure, Feser does not so much set forth or defend such principles as he thinks and argues in accordance with them. But he does set forth and defend the theses that are specific to and indeed define any specifically Aristotelian version of rationalism, those of the theory of actual being and potential being, in short, of act and potency, and the distinction between them. Thus the characterization (pp. 18, 19, etc.) of change as “the actualization of a potential.”
Third, the book’s perspective is thoroughly and straightforwardly Aristotelian in upholding in addition the thesis that philosophy, more specifically, metaphysics, and, more specifically still, natural theology are, not just speculative theories, but demonstrative sciences. That is, it is held, within them there are to be found arguments that are not only valid and sound, arguments, but indeed also demonstrative or apodictic arguments, in a word, proofs. And thus the book’s primary claim, that natural theology can prove the existence of God in, as its title tells us, [at least] five ways. As Feser puts it (p. 15):
A long line of thinkers, from the beginnings of Western thought down to the present day—Aristotelians, Neo-Platonists, Thomists and other Scholastics, early modern rationalists, and philosophers of some other schools too, whether pagans, Jews, Christians, Muslims, or philosophical theists—have affirmed that God’s existence can be rationally demonstrated by purely philosophical arguments. The aim of this book is to show that they were right, that what long was the mainstream position in Western thought out to be the mainstream position again.
I have for decades now, since undergraduate days, understood full well that the Aristotelian tradition has viewed the philosophical disciplines as, at least in principle, philosophical sciences and at least some of the classical arguments for the existence of God as demonstrative arguments. Still, when I read the above passage of Feser, I found myself, on the one hand, enjoying a refreshed appreciation of just what those views are, and, on the other, a determination to put his claim to the test: that is, I found myself committed to the task of determining which of the theses advanced in his book are supported by arguments both explicit and valid, sound, and demonstrative, most particularly those theses immediately involved in the purported proofs of the existence of God.
And that led me to see more clearly than before what one of the primary aims of my ongoing series of posts devoted to the reading of and reflecting upon Aquinas’s Commentary on Aristotle’s Metaphysics has been, that of determining which of the theses, if any, of the Aristotelian metaphysics have been actually proven by Aquinas in the Commentary; this in turn is a purpose subordinated to that of determining which of the theses, if any, of the theses of, finally, metaphysics are supported by arguments both explicit and valid, sound, and demonstrative, most particularly those theses immediately involved in the purported proofs of the existence of God.
It is in line with these aims that although, in my posts of July 16, 2017, and August 19, 2017, the “Aquinas’s Argument That One Science Must “Rule” the Others. A Critical Assessment” and “Aquinas’s Argument That Wisdom Is the Ruler of the Other Sciences. A Critical Assessment,” respectively, I found two central arguments of the first paragraph of Aquinas’s “Prologue” to his commentary to be both valid, in that, if their premises true, their conclusion has to be true, I did not find it to be evident that they are also sound. That is, though it is evident in both cases that that the arguments are valid, it is not evident that, in addition, their premises, and therefore also their conclusions, are all true. Much less, I will add now, is it evident that they are demonstrative.
Let me close by noting that, along with other works by Feser, his Five Proofs will serve as a constant companion as I work my way through Aquinas’s commentary on Aristotle’s Metaphysics. That, it seems to me, is reason enough for me to identify this introduction to Feser’s work as the seventh in the series of posts dedicated to the sustained reading of and commentary upon Aquinas’s.
Until next time.
* You may easily purchase a copy of Five Proofs through Amazon.com., by simply clicking on the following:
** Thomas Aquinas, Commentary on the Metaphysics of Aristotle. Translated and introduced by John P. Rowan (Revised edition; Notre Dame, Indiana: Dumb Ox Books, 1995 )
This edition of Aquinas’s text is serving as the text at hand in the present series of readings and comments. It is available online, at:
If you prefer to do your reading in hard copy, you may easily purchase a copy of the work through Amazon.com., by simply clicking on the following: