 A further objection to Malebranche’s occasionalism from one of his contemporaries is found in the work of Bernard le Bovier de Fontenelle (1657–1757), the eventual perpetual secretary of the Paris Académie des Sciences. In his 1686 Doutes sur le système physique des causes occasionelles, Fontenelle argues that Malebranche’s mechanistic physics is incompatible with his occasionalism. This is so because according to mechanism, bodily collision necessitates change in motion. But then bodily collision satisfies Malebranche’s main requirement for being a true cause insofar as it has a necessary connection to its effect; thus the conflict with occasionalism. In his 1688 Entretien sur la métaphysique, Malebranche offers the response that the laws governing the bodily effects of collision derive from God’s will rather than from the nature of bodies (Malebranche [OC], 12:164). For different assessments of this response to Fontenelle, cf. Downing (2005) and Schmaltz (2008).