Thomas Aquinas on the Immateriality of the Human Intellect by Adam Wood

Abstract

Reviewed by: Thomas Aquinas on the Immateriality of the Human Intellect by Adam Wood Daniel D. De Haan Thomas Aquinas on the Immateriality of the Human Intellect. By Adam Wood. Washington, D.C.: The Catholic University of America Press, 2020. Pp. 335. $75.00 (hardcover). ISBN: 978-0-8132-3256-0. I was keen to review Adam Wood’s recent contribution to debates on Aquinas’s arguments for the immateriality of the intellect. I immediately discovered his book treats far more than my narrow interest had anticipated. In six engaging chapters Wood explores an impressive array of disputed questions on Aquinas’s views on the physical and metaphysical aspects of the human soul and intellectual powers. The arguments for the immateriality of the intellect are confined to the fifth chapter, but Wood does show—sometimes surprisingly— how many different debates are directly relevant to understanding Aquinas’s [End Page 307] contentions that the human soul is incorporeal, immaterial, incorruptible, immortal, and compatible with the resurrection. The questions driving each stage of Wood’s monograph are clearly sign-posted and typically are variations on two basic questions: What should we say is Aquinas’s view on X, given rival readings of Aquinas’s view on X? and what are the philosophical merits of holding such a view today? Most of the book is dedicated to an accurate interpretation of Aquinas’s positions, which Wood helpfully situates amongst the positions and objections of Avicenna, Roger Mareston, Francisco Suárez, David Armstrong, Saul Kripke, William Jaworski, and many other historical and contemporary thinkers. For these investigations alone I heartily recommend Wood’s study to anyone interested in a critical survey and contribution to the major disputes orbiting Aquinas on the intellect’s immateriality. Before considering some challenges to Wood’s argument for the intellect’s immateriality, I will give an overview of the book’s major theses. Chapter 1, “Forms as Limiting Principles,” commences with Aquinas’s hylomorphism. The central challenge is squaring hylomorphism with Aquinas’s contention that the intellectual soul is an immaterial form that can subsist apart from the body. Wood shows why explicating matter and form as “stuff and structure” or “referent and truthmaker” cannot meet this challenge, but the analogy of being can. He explains how Aquinas’s sixfold division of being illuminates an understanding of form as an immaterial mode of being and limiting principle of esse which can be directly participated in without matter. The human intellect “is an accidental form inhering directly in the human soul, rather than in the human being as a whole. Consequently, the human intellect has its act of being in an immaterial mode. This is what Aquinas primarily means by asserting its immateriality” (39). Wood marshals these resources to defend two theses of Aquinas. First, contrary to universal hylomorphism, the intellect can directly inhere in the rational soul alone; it need not inhere in a composite of form and spiritual matter. Second, that the rational soul both subsists in itself and informs matter is philosophically justifiable and coherent. Chapter 2, “Forms as Essences, Structures, Truthmakers, and Powers,” clarifies that “form” can mean either the essence as a whole—including matter and form—or the formal part of an essence, like souls and other substantial forms. Because Aquinas rejects the plurality of substantial forms, he maintains that the soul provides the single overarching structure for the essence of the whole composite. Essences locate composites within a kind or species. “Yet within the essence it is the form of the part that does the important identity-determining work, because matter on its own, or prime matter, is pure potentiality, and not actually anything at all. It takes some structuring or ‘perfecting’ by a form of the part for matter to exist in act as flesh, bones, or anything else” (72). The soul also plays a “unifying role” as the “overarching structure” that unites “material components into a single composite whole synchronically, and maintains its unity diachronically even as it cycles bits of matter in and out throughout its career” (73). Additionally, Wood identifies the [End Page 308] roles substantial forms play as grounding powers and other properties of the composite...