The aim of this dissertation is to provide a critique of the idea that skepticism was the driving force in the development of early modern thought. Historian of philosophy Richard Popkin introduced this thesis in the 1950s and elaborated on it over the next five decades, and recent scholarship shows that it has become an increasingly accepted interpretation. I begin with a study of the relevant historical antecedents—the ancient skeptical traditions of which early modern thinkers were aware—Pyrrhonism and Academicism. Then (...) I discuss the influence of skepticism on three pre-Cartesians: Francisco Sanches, Michel de Montaigne, and Pierre Charron. Basing my arguments on an informed understanding of both ancient Greek skepticism and some of the writings of these philosophers, I contend that it is inaccurate to predominantly characterize Sanches, Montaigne, and Charron as skeptics. To support his thesis about the singular influence of skepticism on early modern thought, Popkin says that René Descartes’ metaphysical philosophy was formed as a response to a skeptical threat and that Descartes ultimately conceded to the force of skepticism. He also argues that David Hume was a Pyrrhonist par excellence. I disagree with Popkin’s claims. I argue that Descartes was not as deeply affected by skepticism as Popkin suggests and that it is inaccurate to characterize Hume as a Pyrrhonist. By offering this critique, I hope to make clear to the readers two things: first, that Popkin’s thesis, though it is both enticing and generally accepted by many scholars, is questionable with regard to its plausibility; second, that the arguments I present in this dissertation reveal that further research into the role of skepticism in early modern philosophy is in order. (shrink)

My dissertation has two main parts. In the first half, I draw out an underlying presupposition of Descartes' philosophy: what I term "atomism of thought." Descartes employs a radical procedure of doubt in order to show that the first principle of his philosophy, the cogito, is an unshakeable foundation of knowledge. In the dialogue that follows his dissemination of the Meditations, Descartes reveals that a whole set of concepts and rational principles innate in our minds are never doubted. These fundamental (...) units of thought are indivisible, distinct, and isolated, and enable the possibility of any rational demonstration. Atoms of thought are perfectly individuated because God has created them as such. Likewise, our minds have been fashioned such that we necessarily have a clear and distinct perception every time we alight upon these simple notions. In the second part of the dissertation, I take up critiques of Descartes' view given by Nietzsche and Heidegger. In the chapter on Nietzsche, I attempt to fill a lacuna in scholarship about Nietzsche's commentary on Descartes. More specifically, I argue that once the foundation of God is displaced, the basis for accepting atomism of thought dissolves. In the final chapter, I analyze Heidegger's critique of Cartesian atomism. I first look at Heidegger's critique of classical truth as correspondence from Being and Time, and show how it is relevant to a critique of atomism. Then I show how the early Heidegger's holistic philosophical framework can provide an alternative that avoids the pitfalls of atomism. While I limit the scope of my analysis to Descartes' particular formulation, atomism of thought was an influential doctrine throughout modern philosophy. This aspect of Cartesianism has persisted and continues to be a significant theoretical underpinning of many contemporary views. It is my contention that Nietzsche and Heidegger have important contributions to make to this area of thought, and the relative neglect of their work in recent scholarship is a detrimental oversight. (shrink)

: It is generally accepted that skeptical scenarios must be possible to raise legitimate skeptical doubt. I argue that if the possibility in question is supposed to be genuine metaphysical possibility, the skeptic's reasoning does not straightforwardly succeed. I first motivate the metaphysical possibility requirement on skeptical scenarios : it's a plausible position that several authors accept and that a family of prominent views—sensitivity, safety, relevant alternatives—are committed to. I argue that plausible constraints in modal epistemology show that justification for (...) believing that certain global skeptical scenarios are metaphysically possible rests on some justified beliefs about the external world, and that this undermines the skeptical argument. While there may still be local skeptical challenges, skeptics cannot appeal to the metaphysical possibility of skeptical scenarios to generate global external world skepticism. (shrink)