William of Ockham on Metaphysics: The Science of Being and God by Jenny E. Pelletier (review)

“Ockham never wrote a commentary on Aristotle’s Metaphysics,” Jenny Pelletier tells us at the beginning of this monograph, “but the absence of such a commentary does not allow us to infer that he was uninterested in or skeptical of metaphysics” (1–2). Her central contention is that Ockham had a robust conception of metaphysics as a distinct branch of scientific knowledge concerning being and God. It is an argument worth making insofar as many scholars in recent years have held that Ockham lacks a metaphysics or rejects the possibility of one. In opposing these claims, Pelletier also has much to say about what Ockham’s metaphysics includes and how it relates to other sciences. As the study of being, it considers the categories and other matters of fundamental ontology, thus playing a key role in Ockham’s nominalist project of ontological reduction—a role Pelletier insists is not usurped by logic or semantics. Furthermore, as the study of God, Ockham’s metaphysics contributes importantly to his theology in ways that belie some traditional objections against it.

Chapter 1 describes Ockham’s understanding of the nature of science with the aim of establishing that metaphysics meets his criteria. Strictly speaking, science is a habit of evidently cognizing true and necessary propositions as the conclusions of demonstrations. Crucially, however, Ockham also explains the conditions under which such cognitive habits are grouped together to form an aggregate science. Pelletier’s analysis of these conditions is perhaps the most important feature of the book. It includes considering the different senses in which a subject may be regarded as “primary” within a given aggregate science, and the possibility of overlap and “subalternation” between different sciences. It allows Pelletier to mount her initial argument for Ockham’s conception of metaphysics as a science: metaphysics is an aggregate of all the scientific habits in which we grasp propositions featuring the term ‘being’ as their subject or predicate. Hence, “being” is the first subject of metaphysics by “primacy of predication,” although by “primacy of perfection” that place goes to God, as the most perfect being it studies.

In chapter 2, Pelletier takes up Ockham’s theory of concepts and concept-formation, explaining how he thought we arrive at a concept signifying and truly predicable of all beings. Part of her aim here is to further defend her central conclusion. The existence of a concept of being, she says, “is decisive for justifying the claim that Ockham has a concept of metaphysics” since “it means that the metaphysician has a delineated and circumscribed subject matter” (127). In addition, the chapter provides helpful answers to several questions I still had by this point in the book: Why does it fall to metaphysics, rather than logic or semantics, to consider the categories and other matters of fundamental ontology? What keeps metaphysics, with its maximally broad subject matter, from collapsing into a mere “sum of all sciences” (142)? Pelletier draws effectively on her previous discussion of overlapping and subalternate sciences to answer these questions.

Less successful, in my view, are her efforts in chapters 3 and 4 to absolve Ockham of some traditional charges against his theology. In chapter 3, for instance, Pelletier follows up an excellent discussion of the univocity of Ockham’s concept of being by addressing the worry that applying this concept univocally to God and creatures might endanger the “maximum dissimilarity” between them. She denies it. But she recognizes that preserving this dissimilarity requires an answer to the question (as she puts it), “what then is the ontological justification of the univocal predication of concepts and words over God and creatures?” (196). She concludes that the solution lies in the “thinness” of the concept of being. Its lack of “deep content” allows us to predicate it of maximally dissimilar objects, whereas we could not do this if it signified anything more. Perhaps. But a critic might...