Etienne Gilson’s essential book on philosophy and its history

You might suppose from the title of Etienne Gilson’s The Unity of Philosophical Experience [orig. 1937; Ignatius Press, 1999] that it is a book about philosophy in general. And ultimately it is.

But its bulk is devoted to detailed accounts of the ideas of thinkers Gilson regards as having gotten things badly wrong, such as Abelard, Ockham, Descartes, Malebranche, Kant, and Comte. There is relatively little about thinkers Gilson regards as having gotten things largely right, such as Aristotle and Aquinas. This might seem odd. For the sympathetic reader might suppose that the experience of philosophers like Aristotle and Aquinas should surely count as least as much as (indeed, more than) that of more wayward thinkers, when elucidating the nature of philosophy.

But such a reaction would reflect a misunderstanding of the book’s title. “Philosophical experience,” as Gilson uses the phrase, has nothing to do with some way of life or psychological profile that philosophers share in common. He’s not concerned with “what it’s like to be a philosopher,” as Thomas Nagel might say.

A clue to what he does mean is provided by the titles he gives the book’s first three parts, viz. “The Medieval Experiment,” “The Cartesian Experiment,” and “The Modern Experiment.” The “experience” referred to in Gilson’s title is analogous to the experience on which empirical science rests. It has to do with a kind of experimentation to which certain philosophical ideas have, in a way, been put.

What way is that?

Gilson holds that “the history of philosophy is to the philosopher what his laboratory is to the scientist.” The theories of empirical science entail predictions which can be tested by observation. By contrast, metaphysical theories, which concern matters that transcend what can be observed, cannot be tested that way. All the same, such theories also have their entailments, and if a metaphysical theory leads to conclusions that are incoherent or otherwise known to be false, then we have grounds for rejecting it.

Now, given the limitations of the individual human intellect, not all the implications of a metaphysical theory are ever worked out or understood by the individual thinker who came up with it. We need to look to what his successors had to say in developing further the thinker’s premises, taking them in new directions, criticizing them, and so on. Hence, it is to the history of philosophy, rather than to the laboratory, that we must look in order to test metaphysical theories. The “experiments” to which such a theory is put are, essentially, embodied in the historical record of what happened as the theory was developed and criticized in this way.

What about the “unity” referred to by Gilson in his title?

Gilson is speaking here of the way that, as he argues, a number of philosophical theories from the Middle Ages to the present have made a similar type of opening move and been led thereby into the same problematic outcome. The opening move in question is essentially that of trying to transform metaphysical questions into questions of some other type. The problematic outcome is skepticism about metaphysics. But this skepticism always turns out to be intellectually unsatisfactory, so that it is always followed by a renewed attempt at metaphysics–but often one that makes a new opening move of the same general type, so that the cycle begins again. The lesson this series of experiments teaches us is that it is a mistake to make an opening move of the type in question.

Examples of this sort of move that are discussed by Gilson include the attempt to reduce metaphysical questions to questions of logic, which Gilson associates with Peter Abelard. There is also the attempt to resolve metaphysical questions by way of theology, which Gilson associates with thinkers like Bonaventure. Ockham, Gilson argues, essentially tries to resolve metaphysical questions by appeal to human psychology. Descartes does so by modeling all knowledge on mathematics. Kant, Gilson says, modeled it on Newtonian physics, and Comte on sociology.

Such views (which Gilson calls logicism, theologism, psychologism, mathematicism, physicism, and sociologism, respectively) essentially try to turn metaphysics into something else. They do so by taking one part of reality (such as mathematical truth, or physical reality, or the human mind) and modeling the whole of reality on it.

But metaphysics by its nature is concerned precisely with the whole–with being qua being–so that attempts to make it about a part of the whole, thereby distorting it, will inevitably fail. Critics of metaphysics conclude from this series of failures that there is something wrong with metaphysics itself, but this is a non sequitur. For the failures reflect the distortion of metaphysics rather than anything in the nature of metaphysics itself. And that metaphysical inquiry keeps reviving even in the wake of these failures reflects the fact that there are real questions that it alone can address–questions that go deeper than those addressed by the other branches of human knowledge that too many metaphysicians have mistakenly tried to model metaphysics on.

This is the context in which Gilson makes his famous remark that “philosophy always buries its undertakers”. This, he suggests, is a “law” established by the philosophical “experiments” he has described in the book (in a way analogous to the manner in which physical laws are established by physical experiment). And there are further laws that are so established, such as the law that “by his very nature, man is a metaphysical animal” and the law that “as metaphysics aims at transcending all particular knowledge, no particular science is competent either to solve metaphysical problems, or to judge their metaphysical solutions”.

He takes “philosophical experience” thereby to have vindicated the approach of thinkers like Aristotle and Aquinas (though he emphasizes that this does not entail that they have given us the last word).

Gilson’s account suggests the following analogy (mine, not his). Heresy, in the strict theological sense, involves plucking some element of Christian doctrine out from its larger dogmatic context and thereby distorting it. (The word “heresy” comes from the Greek hairesis, which connotes “taking” or “choice.”) For example, Monophysitism so emphasizes Christ’s divinity that it destroys his humanity, thereby distorting the thesis that Jesus is God. Modalism so emphasizes divine unity that it destroys the distinctness of the three divine Persons, thereby distorting the doctrine of the Trinity. And so on. The metaphysical errors Gilson describes are analogous to this, insofar as they involve “taking” or “choosing” some part of reality (mathematics, physics, mind, or whatever) and erroneously modeling the whole on it, thereby distorting both the whole and the part.

We can extend the analogy further. Pope St. Pius X, in Pascendi Dominici Gregis, famously characterized modernism as “the synthesis of all heresies.” Philosophy since the time of Ockham has had an analogous character, so that it is no accident that most (though, admittedly, not all) of what Gilson recounts in The Unity of Philosophical Experience occurred after his time, and during the post-medieval period especially.

Modern philosophy can therefore be characterized as a kind of “synthesis of all metaphysical errors.” It has recapitulated errors seen previously in the history of philosophy (such as in the Pre-Socratic period) but ramified and exacerbated them, and in a relatively short historical period. And because the moral and political errors characteristic of the modern world have followed from these metaphysical errors, Gilson’s book is a key text for understanding not just modern philosophy, but modernity in general.

(Editor’s note: This essay originally appeared on Dr. Feser’s blog in a slightly different form and is reprinted here with the author’s kind permission.)