Abstract

In this account of the philosophical and scientific pursuits of Pierre Gassendi , I challenge a traditional view which says that the inspiration, motivation, and demonstrative grounds for his physical atomism consist not in his empiricism but in his historicist commitments. Indeed, Gassendi suggests that it's a consequence of our best theory of knowledge and sound scientific method that we get evidence which warrants his microphysical theory. ;The primary novelty of his theory of empirical knowledge is his proposal, against the Stoics and Descartes, that it is not a necessary condition of our knowing some claim that we are certain of it. This move immediately broadens the scope of what we can know through the senses, as does his suggestion that we include among such knowledge claims those assertions about what is hidden to the senses which we legitimately infer from the evidence of the perceptually given. ;On the basis of these epistemological positions, Gassendi develops his views on scientific method according to which we attain and justify our best empirical claims by deduction yet, he believes, these claims are at root probabilistic, and we may maintain hypotheses as the basis of our scientific reasoning so long as there is some empirical evidence for them, however broadly construed. ;Hence Gassendi suggests that his atomism constitutes a 'most likely hypothesis' for which we have empirical evidence--which of necessity is found indirectly in 'indicative' signs, those surface level phenomena for which he takes the existence of atoms to be a sine qua non condition. Perhaps the paramount case of such evidence consists in those microscopic observations of crystalline formation and dissolution that he takes to demonstrate the molecular structure of matter--a key and innovative consequence of his atomism. ;The robust character of Gassendi's method emerges in his appeals to indirect evidence for claims about the unobservable and his willingness to count this as adequate empirical grounds for maintaining an atomist hypothesis. Remarkably, he stands at the dawn of the modern era with at least a proposal as to how to resolve one of empiricism's more vexing difficulties, still with us in some form today