One of the distinctive features of modern science is a commitment to empiricism—a fundamental expectation that theoretical hypotheses will survive encounters with observations. Those that comport with the theory's explanations and predictions confirm the theory. Anomalous observations that do not fit theoretical expectations disconfirm it. Moreover, experiments can be contrived to generate observations that might serve to confirm or disconfirm a theory. Philosophers of science may disagree as to how exactly all of this is supposed to work, but the basic (...) empiricist expectation almost goes without saying. To deny it is to rule one's self out of the bounds of the scientificenterprise.Strange as it might seem to modern... (shrink)

John Arbuthnot's celebrated but flawed paper in the Philosophical Transactions of 1711-12 is a philosophically and historically plausible target of Hume's probability theory. Arbuthnot argues for providential design rather than chance as a cause of the annual birth ratio, and the paper was championed as a successful extension of the new calculations of the value of wagers in games of chance to wagers about natural and social phenomena. Arbuthnot replaces the earlier anti-Epicurean notion of chance with the equiprobability assumption of (...) Huygens's mathematics of games of chance, and misrepresents the birth ratio data to rule out chance in favour of design. The probability sections of Hume's Treatise taken together correct the equiprobability assumption and its extension to other kinds of phenomena in the estimation of wagers or expectations about particular events. Hume's probability theory demonstrates the flaw in this version of the design argument. (shrink)

In the Optics, Descartes claims that telescopes and microscopes lead to morally certain knowledge. It is unclear, however, that Descartes’s expressed confidence in these instruments is warranted. In this article, I show how a limited range of telescope and microscope observations could lead to morally certain knowledge for Descartes, and how observations beyond this range admit of enough reasonable doubt to undermine moral certainty. I also explain moral certainty as a form of knowledge in Descartes’s scientific practices, his epistemic commitment (...) to optical instruments, and I offer an explanation for why Descartes never used optical instruments in his scientific endeavours. -/- ---- -/- Dans la Dioptrique, Descartes prétend que les télescopes et les microscopes donnent accès à des connaissances moralement certaines. Cependant, il n’est pas certain que la confiance accordée par Descartes à ces instruments soit justifiée. Dans cet article, je montre comment une gamme limitée d’observations effectuées à l’aide d’instruments d’optique pourraient mener aux connaissances moralement certaines pour Descartes, et comment d’autres observations allant au-delà de cette gamme introduisent suffisamment de doute raisonnable pour saper cette certitude morale. Enfin, j’interprète la certitude morale comme une forme de connaissance dans l’empirisme de Descartes, j’explique son engagement épistémique envers les instruments d’optique, et j’éclaire les raisons pour lesquelles il n’a jamais employé d’instruments d’optique dans ses propres recherches scientifiques. (shrink)