Petri Gassendi Disquisitio metaphysica seu dubitationes et instantiae adversus Renati Cartessi metaphysicam & responsa.
Amsterodami : Apud Iohannem Blaev ;1644 $ 3,000
From the most wonderful “Stanford Encyclopedia of Philosophy”
In 1641 the theologian and mathematician Marin Mersenne invited Gassendi and several other eminent thinkers to contribute comments on the manuscript of René Descartes’s Meditations (1641); Gassendi’s comments, in which he argued that Descartes had failed to establish the reality and certainty of innate ideas, were published in the second edition of the Meditations (1642) as the fifth set of objections and replies. Gassendi enlarged upon these criticisms in his Disquisitio metaphysica, seu duitationes et instantiae adversus Renati Cartesii metaphysicam et responsa (1644; “Metaphysical Disquisition; or, Doubts and Instances Against the Metaphysics of René Descartes and Responses”).
“For many commentators, Gassendi’s empiricist theory of knowledge and objections to Descartes’s Meditations count as his paramount philosophical contributions. In his core epistemology, he offers the first modern model of knowledge from the senses to be integrated with a physiological account of perception. In his objections to Descartes, he rejects the clarity and distinctness criterion, seeks to undermine the reasoning behind the cogito, and assails the ontological argument. Each of these views represents a battle Gassendi has taken up against the Aristotelian tradition or the Cartesian stance; his thoroughgoing empiricism poses an alternative to both of these competing perspectives.One cornerstone of Gassendi’s anti-Aristotelianism is the suggestion that there is nothing necessary about the way the world is. God, he proposes, could have made the world work in any number of ways, and the contingent history and character of Creation means that there is nothing immutable about the essence of a material thing. (That a ‘substance’, in either the Aristotelian or Cartesian sense, might have an immutable essence, is a different matter, and insofar as Gassendi has such a notion (for example, with respect to space, time, matter, and void) he agrees that such things feature unchangeable sine qua non characteristics.) Moreover, Gassendi maintains, regardless of whether there are any essences and whether they might be mutable, there are none to which we have any epistemic access. The sole originating source of our knowledge is the information the senses provide, such that what we know is closely linked to what we can perceive. However, as Descartes notes, we can perceive only appearances. Gassendi draws from this point the very uncartesian lesson that appearances are all we can know about, too—thereby ruling out knowledge of unperceivable essences. One line of this reasoning can be found in his discussion of classical skeptical tropes concerning the relativity of evidence from the senses to individual experience—that honey tastes sweet to me, though bitter to you; and that fire seems hot to us, though not so to insects that live near fire (O III (DM) 388b; R 535). Since different people have distinct experiences, our knowledge of honey’s taste or fire’s heat differs from person to person and thus is not a reliable guide to invariable characteristics of, for example, the honey or fire. In cases like these we know a thing’s qualities only as we record them on a subjective basis. Such sensory information, based on experiences which vary intersubjectively, cannot yield judgments about a thing’s qualities which do not vary in that (or any other) way. Hence we lack knowledge of the thing’s essence, if indeed there is one. More broadly, from our principal source of ideas—the senses—we know only how things appear to us (O III (DM) 311b-312a; R 184). (If we are to have knowledge of an object’s essence, Gassendi proposes, such requires a “perfect interior examination” of that object, which is apparently not something we may gain from empirical study.) ”
Gassendi believed that there was no conflict between his mechanistic atomism and the doctrines of Roman Catholicism; indeed, he took pains to emphasize their compatibility. Although his works were originally published in latin , a French abridgement of them appeared in the second half of the century, as did English translations of various excerpts. His ideas were taught in Jesuit schools in France, in English universities, and even in newly founded schools in North America. Gassendi and Descartes both believed that all natural phenomena could be explained in terms of matter and motion alone. They disagreed about the details of their mechanical accounts of the world, in particular about their theories of matter and their approaches to scientific method.