Cartesian Metaphysics: The Scholastic Origins of Modern Philosophy (review)

Descartes scholars can welcome this book. Secada supports trends in scholarship that criticize seeing Descartes as merely an anti-skeptical foundationalist, and he challenges many prominent interpretations of Descartes's metaphysics. In addition, Secada helpfully references Scholastic sources to provide context for Descartes's views. This book is also valuable for philosophers in contemporary metaphysics and epistemology. Secada uses the tools and idiom of analytic philosophy to explain and defend Descartes, and he is sympathetic to Descartes's project, even if he grants that aspects of it "are difficult to articulate clearly and convincingly" (174).

The book's central theme is the contrast between Descartes's "essentialism" and the "existentialism" of Scholastics. Secada explains the distinction as follows: "Essentialism (existentialism) is the doctrine, first, that one cannot know the existence (essence) of any substance without first knowing its essence (existence), and, secondly, that one can know the essence (existence) of some substance without knowing its existence (essence)" (8). Cartesian Metaphysics interprets Descartes's corpus as a defense of essentialism in the light of Scholastic existentialism.

The first three chapters set the stage. Chapter One distinguishes essentialism from existentialism. Chapter Two provides historical background necessary to understand the role of Scholasticism in Descartes's thought. Chapter Three discusses the role of Christian Platonism in both Descartes and the Scholastics, especially their shared Augustinian presupposition that knowledge of essences is of "how things are in themselves" (56).

The next three chapters discuss the metaphysical status of ideas. In Chapter Four, Secada contrasts Descartes's "immanent" theory according to which "the immediate objects of ideas must exist in the mind" (85) with the "realist Scholastic" theory that "takes mental acts to be immediately directed towards things" (83). In Chapter Five, this account is applied to an interpretation of the Second Meditation as a defense of intellectualist essentialism against Scholastics and empiricists. "Contrary to the Scholastics and other empiricists, Descartes attributed to the intellect and not to the senses the power to reach the world of substances existing outside of the inner theatre of the mind" (116). Through comparing Descartes with Suarez and Gassendi, Secada argues that all the proofs of existence in the Meditations, including for the cogito, argue from knowledge of essence to knowledge of existence. Chapter Six turns to Descartes's proofs for the existence of God. According to Secada, even for a posteriori proofs, knowledge of God's existence depends on knowledge of his essence.

The last three chapters examine Descartes's theory of substance. Chapter Seven reconstructs Descartes's distinction between substances and properties. A substance is something that "exists without inhering" and "exists uncaused" (185). Secada discusses the nature of substance, how substances other than God can be "uncaused," and the plausibility of Descartes's sharp distinction between substances and properties. The chapter ends by arguing that Descartes's doctrine about the relationship between substances and properties inadvertently "heralds Spinoza's pantheism" (185). Chapter Eight examines real and essential properties in Cartesian metaphysics in contrast to Suarez and Fonseca, and ends with a partial defense of Descartes's ontological argument. Chapter Nine offers a detailed discussion of two fundamental substances in Descartes's metaphysics: body and mind. Secada argues that Descartes offers no satisfactory explanations of body, mind, or the relationship between the two.

As is clear from this brief summary, Cartesian Metaphysics is a rich book. It presents important historical details without endless irrelevant details (see especially the sketch of Descartes's Scholastic background on 27-33). The exegetical arguments make strong cases for new interpretations of Descartes. Secada effectively shows that Descartes is more concerned with metaphysics than with refuting skepticism. Comparisons with Suarez and Fonseca shed new light on Cartesian arguments. Reconstructions of Cartesian arguments even tempt one to take Descartes seriously in contemporary metaphysics. And the criticisms of Descartes are thought-provoking.

Unfortunately, the...