Reviewed by: The Chemical Philosophy of Robert Boyle: Mechanicism, Chymical Atoms, and Emergence by Marina Paola Banchetti-Robino Laura S. Keating Marina Paola Banchetti-Robino. The Chemical Philosophy of Robert Boyle: Mechanicism, Chymical Atoms, and Emergence. New York: Oxford University Press, 2020. Pp. x + 196. Hardback, $85.00. The past thirty years have seen substantive debate on the nature of Robert Boyle’s self-described “Mechanical” or “Corpuscularian” philosophy, its treatment of kinds and qualities, its relation to his experimental studies, its relation to other sixteenth- and seventeenth-century matter theories, and its role in the development of chemistry. Using several different strands from this literature, Marina Banchetti-Robino aims to show how Boyle addresses issues relevant to philosophy of chemistry today: the emergent nature of chemical properties (chapter 4), the mereology of fundamental chemical wholes (chapter 5), and the nonreducibility of chemistry to physics. The last issue frames the whole book, which she describes as “a careful and critical look at how Boyle helps to define the transition from the physics of the mechanical philosophy to a modern conception of chemistry” (7). Specifically, she presents Boyle’s dissatisfaction with a Cartesian particle-level approach (chapter 2) in terms of Boyle’s aiming to revise it to save chemistry: “The challenge for Boyle is to provide empirical support for mechanistic corpuscularianism without sacrificing chemistry itself. To succeed in this task, Boyle revises the mechanical hypothesis to accommodate ontological realism about chemical properties and about their causal agency in nature. Thus, he develops a nuanced theory of matter that combines a mechanistic conception of fundamental particles with a realist ontology of chemical qualities, causes, and substances” (85). Her interpretation involves two main threads. One presents how Boyle expands a Cartesian explanatory basis to include stable, structured aggregates to ground chemical kinds. She traces this innovation back to earlier nonmechanistic corpuscular theories (chapter 1) and, using William Newman’s term ‘chymical atom’ for the stable corpuscles of homogeneous substances revealed through chemical experimentation, connects Boyle’s theoretically posited aggregates with his experimental work and realism for chemical kinds (chapter 3). The second, problematic, thread presents Boyle’s project in natural philosophy to be, in part, “to accommodate ontological realism about chemical properties and about their causal agency in nature” (85). She takes this realism about qualities to be established by Boyle’s formulating “a conception of chemical properties as emergent, dispositional, and relational” (77), and by a “complex corpuscularian ontology that allows him to formulate autonomously chemical explanations in which structural differences account for chemical differences, chemical properties have causal power, and material bodies with different essential properties belong to different material species” (77–78). One can accept the thread involving “chymical atoms” without accepting her view of Boyle’s goal regarding qualities. The problem with the latter is that it turns Boyle’s project there on its head: it treats [End Page 508] Boyle’s explananda—causally efficacious qualities that are a large part of the phenomena of nature—as theoretically justified explanantia. One culprit here is understanding Boyle as trying to replace a narrow mechanistic explanatory approach, “strict mechanicism,” that allows explanation of natural phenomena only in terms of the shape, size, and motion of individual particles of matter. That there was such a sect has been contended in the literature, as Banchetti-Robino herself notes. Nonetheless, she represents Boyle as rejecting such explanations not merely because they are doubtful or too speculative but because they would undermine the existence of chemistry. She writes that Boyle was “not satisfied with simply explaining all chemical reactions and transformations by appealing to the motions and other mechanical affections of fundamental particles. Boyle clearly understood that strict mechanicism held negative implications for considering chemistry as a systematic natural philosophy independent of mechanics or, to use more contemporary terminology, for considering chemistry as an autonomous science with its own distinctive explanations” (68). If one is not convinced that Boyle saw prior mechanical philosophers’ explanatory bases constrained in that chemistry-threatening way, then her overall framing of Boyle’s aims appears misguided. Further, it is not explained why Boyle’s specification of chemical explananda is insufficient to safeguard chemistry a place in natural philosophy. A...