: This paper presents a detailed account of Descartes' derivation of his second law of nature—the law of rectilinear motion—from a priori metaphysical principles. Unlike the other laws the proof of the second depends essentially on a metaphysical assumption about the temporal immediacy of God's operation. Recent commentators (e.g., Des Chene and Garber) have not adequately explained the precise role of this assumption in the proof and Descartes' reasoning has continued to seem somewhat arbitrary as a result. My account better (...) reveals the dependence of the second law on fundamental principles about time and causality. (shrink)

Utilizing Einstein’s comparison of General Relativity and Descartes’ physics, this investigation explores the alleged conventionalism that pervades the ontology of substantival and relationist conceptions of spacetime. Although previously discussed, namely by Rynasiewicz and Hoefer, it will be argued that the close similarities between General Relativity and Cartesian physics have not been adequately treated in the literature—and that the disclosure of these similarities bolsters the case for a conventionalist interpretation of spacetime ontology.

As críticas de Newton e Voltaire endereçadas à negação do vazio por parte de Descartes compartilham uma estrutura básica: ambos parecem concordar que tal tese cartesiana conduz a implicações indesejáveis tanto no campo da mecânica, quanto no que diz respeito à teologia. Entretanto, embora Newton admita as implicações teológicas da negação do vazio, elas não constituem o fim último de sua crítica, o que parece ocorrer na crítica de Voltaire. Ao contrário, os argumentos newtonianos para assumir o vazioencontram na mecânica (...) não apenas um campo de prova; eles constituem uma parte importante da fundamentação de um dos pilares do newtonianismo: o espaço absoluto. (shrink)