Corpuscles, Mechanism, and Essentialism in Berkeley and Locke

Corpuscles, Mechanism, and Essentialism in Berkeley and Locke MARGARET ATHERTON MUCH OF THE RECENT WORK Oil Locke and, to some extent, on Berkeley as well has stressed corpuscular mechanism as central to an understanding of their work. Indeed, in the case of Locke, it is close to becoming a contemporary orthodoxy that Locke's motive in writing the Essay was tO provide a foundation or a defense for corpuscular mechanism? There is as well a growing literature devoted to showing that Berkeley too had a close involvement with corpuscular science, although, in his case, as a critic. ~ This attention to corpuscular mechanism has raised two different but related puzzles. The first is that Locke, the enthusiast of corpuscles, has a number of negative things to say about them, 3 and the second is that Berkeley, the critic, appears on at least some occasions to be happy to talk about corpuscles and what they do. 4 | think these puzzles can usefully be discussed together because, even though the A recent paper by Arnold Davidson and Norbert Hornstein says that this is a position with which "everyone now agrees" ("The Primary/SecondaryQuality Distinction: Berkeley, Locke and the Foundations of Corpuscular Science," Dialogue23 [1984]: 281-3o3). ' See, for example, Nancy L. Maull, "Berkeley on the Limits of Mechanistic Explanation," in Colin Turbayne, ed., Berkeley:Criticaland InterpretiveEssays(Minneapolis: Universityof Minnesota Press, 1982), 95-1~ Margaret D. Wilson, "Did Berkeley Completely Misunderstand the Basis of the Primary-SecondaryQuality Distinction in Locke?" in Turbayne, ed., Berkeley,lO8-123; Barry Stroud, "Berkeley v. Locke on Primary Qualities," Philosophy55 (April 198o): 149-66. See, for example, Maurice Mandelbaum, Philosophy,Scienceand SensePerception(Baltimore: Johns Hopkins Press, 1964); Margaret D. Wilson, "Superadded Properties: The Limits of Mechanism in Locke," AmericanPhilosophicalQuarterly 16 (1979): 143-5o; and M. R. Ayers, "Mechanism, Superaddition, and the Proofs of God's Existence in Locke's Essay,"The PhilosophicalReview 9~ (1981): 210--51. I have written on this issue in "Knowledge of Substance and Knowledge of Science in Locke's Essay,"HistoryofPhilosophyQuarterly 1 (1984): 413-28. 4 See I. C. Tipton, "The 'Philosopher by Fire' in Berkeley's Alciphron," in Turbayne, ed., Berkeley, 159-73; Daniel Garber, "Locke, Berkeley and Corpuscular Scepticism," in Turbayne, [471 48 JOURNAL OF THE HISTORY OF PHILOSOPHY 29"1 JANUARY 1991 problems differ, they stem from a related source: what I believe to be a misconception of science in the seventeenth and early eighteenth century, in which the importance of corpuscular mechanism has been exaggerated. The puzzles can in fact be dissolved if corpuscular mechanism is set in a wider context. As I hope to show, this wider context permits a somewhat more complicated view of how both Locke and Berkeley relate to the science of their time and to each other. I should add that, arguing as I am for greater complexity , what I am going to propose here can only be regarded as an introductory description of a general case to be made. The puzzle about Locke is that, though he accepts and makes use of theorizing in terms of corpuscles, he also points to a number of problems about their use. In one place or another, Locke says that we are unable to explain how particles cohere 5(2.23.23) , how motion is transferred by matter (2.23.28), whether matter is infinitely divisible (2.23. 31), and, most dramatically, that we have no idea how primary qualities give rise to or account for their secondary qualities (4-3-12). On the one hand, Locke clearly believes that there are bodies too small to see, that they are extended, solid, and can move, and that it is relevant in attempting to explain at least some phenomena to refer to the impact of corpuscles on one another. Thus, there seems reason to say Locke was a mechanist. On the other hand, it is far easier to find places in the Essay where Locke explicitly raises difficulties for mechanism than it is to find places where he explicitly attempts to provide a justification for mechanism. 6 The problem has been, then, to find room, within what is taken to be Locke's overall favorable attitude towards corpuscularianism, for the...