Atomism, the Mechanical Philosophy, and Empirical Viability

CHAPTER TWELVE

ATOMISM, THE MECHANICAL PHILOSOPHY, AND EMPIRICAL VIABILITY

Does Gassendi’s atomism have any novel character? This issue, which dominates much of the commentary on Gassendi, may be addressed by paying close attention to the fit of his atomism with a broader mechanical philosophy, and the empirical viability of his atomist hypothesis. One prominent view is that his atomism differs in rela- tively insignificant ways from that of the ancients, and numerous interpreters suggest the notable differences are those which Gassendi himself frequently stresses—the rejection of certain ancient claims on theological or doctrinal grounds, or what Margaret Osler has called the ‘baptism’ of Epicurean views. Yet Gassendi further distinguishes his atomism from its ancient sources by more detailed accounts of macrophysical phenomena such as the forces acting upon, and the manifest qualities of, macrophysical objects. His atomist accounts of magnetism and air pressure, for example, have no exact, detailed forerunners among the ancient atomist writings.1 It is also pertinent in this context to note Gassendi’s rejection of Epicurus’s views not simply on doctrinal grounds but in order to avoid untoward results for his physics or cosmology (which was theo- logically-influenced though not doctrinal). Epicurus, for example, suggests there are infinitely many atoms in infinitely great space for- ever existing across infinite time, which view Gassendi rejects on doctrinal grounds.2 However, Gassendi also cannot accept this

1 Some ancient works provide important steps towards Gassendi’s novel atomist accounts, though. Thus, one likely source for Gassendi’s reasoning regarding the void in his barometric account is Hero’s account of the vacuum, and the rudi- mentary mechanism for Gassendi’s atomist account of magnetism is found in the Lucretian or Democritean accounts of attractive forces. 2 It is not clear that Gassendi’s doctrinal grounds regarding this issue were widely accepted. After all, a number of contemporary authors promoted some form of inﬁnitism without meeting the Church’s criticism. The notion that God might create inﬁnite worlds was licensed by the 1277 condemnation of the Aristotelian denial of the possibility of creating multiple worlds. Bruno may have been burned at the 322 part iii—chapter twelve

Epicurean view because if there were infinitely many atoms, then things might be as they are naturally and without any need for God’s providence—since eventually infinitely many atoms acting on their own might yield the structures and relations familiar to us. Thus it is to preserve not doctrine but God’s ultimate role in determining the outcome of bodily interactions that Gassendi rules out the possibility of an infinite universe and the infinitely many atoms that might inhabit it.3 Completely apart from modifying Epicurean claims, Gassendi crafts a novel atomism insofar as he tailors his views specifically to counter the competing matter theorists of his time, and in particular the pre- mier non-atomist corpuscularian, Descartes. The part of cartesian matter theory which is most unacceptable to Gassendi is the plenist view that matter equals extension, such that there is no space not occupied by matter: In our times appears the famous René Descartes, who considers the world as being neither finite nor infinite but indefinite, as is also in fact matter—which in the beginning occupied the entirety of space or, rather, was itself space (because he does not distinguish space from bodily extension, since he also admits no void at all), then would have been fragmented by God in a way to be resolved into tiny particles comparable to Empedocles’ small fragments or Heraclitus’ bits.4

stake for holding such views, thought the Inquisition records are silent on the matter; q.v. Maurice A. Finocchiaro, “Philosophy versus Religion and Science versus Religion: the Trials of Bruno and Galileo”, in Giordano Bruno: Philosopher of the Renaissance, ed. Hilary Gatti (Aldershot, UK; Burlington, VT: Ashgate, 2002); and F. Beretta, “Giordano Bruno e l’Inquisizione Romana. Considerazioni sul Processo”, Bruniana e Campanelliana 7 (2001) 2, 15–50. The going concern in the seventeenth century was not whether God could create infinite worlds, though. Rather, the worry was over what the universe would be like were that actually the case, and the late Scholastics tended to demur on such claims; q.v. Edward Grant, The Foundations of Modern Science in the Middle Ages: their Religious, Institutional, and Intellectual Contexts (Cambridge; New York: Cambridge University Press, 1996); and Roger Ariew (1999), esp. 167–171. 3 Q.v. his letters to Louis de Valois (Count of Alais) of October 24 and November 7, 1642 (O VI 158a, 159a). One result of this view is that the argument from design—if not for God’s existence, then at least for God’s particular role—requires a very specific design. Leibniz—who read Gassendi as well as Bruno—addressed such a difficulty by his principle of sufficient reason. He thereby guaranteed that, given infinite possible worlds, the world God created was in fact the best possible world, reflecting omniscience and providence at once. 4 O I 257b–258a.