Clear and distinct perception is the centrepiece of Descartes’s philosophy — it is the source of all certainty — but what does he mean by ‘clear’ and ‘distinct’? According to the prevailing approach, what it means for a perception to be clear is that its content has a certain objective property, like truth. I argue instead that clarity is at least partly a subjective, phenomenal quality whereby a content is presented as true to the perceiving subject. Clarity comes in degrees. (...) Any weak degree of clarity, available to the senses, can be merely subjective, since what it presents as true may not actually be true. But complete clarity, available to intellectual perception, has an objective dimension, since what it presents as true is always some truth, some bit of reality. Further, I argue that the other perceptual qualities that Descartes identifies — obscurity, confusion, and distinctness — are all defined in terms of clarity. Of particular note is the fact that distinctness is not a positive feature to be added to clarity: a distinct perception is just a completely clear perception. (shrink)

The category of sympathy marks a number of basic divisions in early modern approaches to action explanations, whether for human agency or for change in the wider natural world. Some authors were critical of using sympathy to explain change. They call such principles “unintelligible” or assume they involve “mysterious” action at a distance. Others, including Margaret Cavendish, Anne Conway, and Gottfried Wilhelm Leibniz, appeal to sympathy to capture natural phenomena, or to supply a backbone to their metaphysics. Here I discuss (...) how concerns about sympathetic actions form at least a partial background for differing seventeenth-century conceptions of what it is to explain action. I argue that critics of sympathy generally insist on an “atomistic” approach to action explanation, which makes primitively relational phenomena come out as problematic. Proponents of sympathy, by contrast, allow for a more holistic approach to action explanation, which allows for such basic connections. Hence, divergent attitudes toward sympathetic action in part explain differences in approaches to explanation. I conclude by showing how some of these core concerns fade into the background when in the eighteenth-century sympathy gets psychologised and individualised. (shrink)

In this paper we study the impact of Leibniz’s critique of infinite numbers in his metaphysics of bodies. After presenting the relation that the German philosopher establishes in his youth between the notions of body, extension and infinite quantities, we analyze his thoughts on the paradoxes of the infinite numbers and we claim that his defense of the inconsistency of such numbers is an inflexion point in his conception of body and mark the beginning of his offensive against the res (...) extensa. (shrink)

How language works — its functions, mechanisms, and limitations — matters to the early moderns as much as it does to contemporary philosophers. Many of the moderns make reflection on language central to their philosophical projects, both as a tool for explaining human cognition and as a weapon to be used against competing views. Even in philosophers for whom language is less central, we can find important connections between their views on language and their other philosophical commitments.

In two rarely discussed passages – from unpublished notes on the Principles of Philosophy and a 1647 letter to Chanut – Descartes argues that the question of the infinite extension of space is importantly different from the infinity of time. In both passages, he is anxious to block the application of his well-known argument for the indefinite extension of space to time, in order to avoid the theologically problematic implication that the world has no beginning. Descartes concedes that we always (...) imagine an earlier time in which God might have created the world if he had wanted, but insists that this imaginary earlier existence of the world is not connected to its actual duration in the way that the indefinite extension of space is connected to the actual extension of the world. This paper considers whether Descartes’s metaphysics can sustain this asymmetrical attitude towards infinite space vs. time. I first consider Descartes’s relation to the ‘imaginary’ space/time tradition that extended from the late scholastics through Gassendi and More. I next examine carefully Descartes’s main argument for the indefinite extension of space and explain why it does not apply to time. Most crucially, since duration is merely conceptually distinct from enduring substance, the end or beginning of the world entails the end or beginning of real time. In contrast, extension does not depend on any enduring substance besides itself. (shrink)

Resumen En este trabajo evaluamos el impacto que la adopción de la relatividad del movimiento tiene en la metafísica de Leibniz. En particular argumentamos que el abandono de la comprensión absolutista del mismo anula su noción juvenil de sustancia corpórea. En primer lugar analizamos cómo entiende Leibniz las nociones de cuerpo y movimiento en el periodo juvenil y defendemos que la comprensión absolutista de este último constituye una piedra angular en su primera concepción de la sustancia corpórea. En segundo lugar (...) exponemos los argumentos leibnizianos a favor de la relatividad del movimiento durante el período parisino y mostramos su repercusión en el concepto juvenil de sustancia corpórea.In this paper we evaluate the impact of Leibniz's defense of relativity of motion on his metaphysics. We argue that the abandonment of the absolutist position makes void his first notion of corporeal substance. First, we analyze Leibniz's conception of body and movement in his youth and explain how the assumption of absolute motion during these years plays a role in his notion of corporeal substance. Second, we examine his arguments in favor of relativity of motion during the Parisian period and show the repercussion on his first conception of the corporeal substance. (shrink)

Writing about the history of science and the history of philosophy involves assumptions about the role of context and about the relationships between past and present ideas. Some historians emphasize the context, concentrating on the intellectual, personal, and social factors that affect the way earlier thinkers have approached their subject. Analytic philosophers take a critical approach, considering the logic and merit of the arguments of past thinkers almost as though they are engaging in contemporary debates. Some philosophers use the ideas (...) of historical figures to support their own philosophical agendas. Scholarly studies of the French natural philosopher Pierre Gassendi (1592–1655) exemplify many of these .. (shrink)

Pierre Gassendi (b. 1592, d. 1655) was a French philosopher, scientific chronicler, observer, and experimentalist, scholar of ancient texts and debates, and active participant in contemporary deliberations of the first half of the seventeenth century. His significance in early modern thought has in recent years been rediscovered and explored, towards a better understanding of the dawn of modern empiricism, the mechanical philosophy, and relations of modern philosophy to ancient and medieval discussions. Through an arch-empiricism—tempered by adherence to key elements of (...) Church doctrine—Gassendi views metaphysics as a realm for speculation grounded in the possibility of empirical confirmation, logic as a psychologistic and probabilistic enterprise, knowledge of the external world as built on and subject to sensory-based evidence, and ethics in quasi-hedonist, possibly quantifiable terms. His philosophy is a constant review of other sources, a thorough consideration of the landscape into which his own empiricism fits and represents an alternative to contrasting claims, past and present. Other hallmarks of his thought include an atomist matter theory, explorations and defenses of the new physics, objections to the Meditations, and refutations of contemporary Aristotelians and mystical thinkers. His presentation of an empiricism, atomism, and new cosmology in historical and philosophical context greatly advanced the community of scholarship in his day, and represents a then-new model of research and exposition. (shrink)

This is about the tension between Epicurean and Galilean accounts of motion in Gassendi. For my more recent thoughts on this, see http://philpapers.org/rec/LOLCEG.

Michael Jacovides For Locke, the first step in inquiring into perception should be reflection: “What Perception is, every one will know better by reflecting on what he does himself, when he sees, hears, feels, etc. or thinks, than by any discourse of mine” (2.9.2). As a second step, I say, we may learn from reading him. Locke’s use of the term ‘perception’ is somewhat broad. At one point, he tells us that “having Ideas and Perception” are “the same thing” (2.1.9). (...) Elsewhere, he includes the perceiving the agreement of ideas and perceiving the meaning of signs among the varieties of perception (2.21.5). What I have to say will be about perception as psychologists classify it nowadays. I will first discuss sensation in general and then elucidate some of the subtleties of Locke’s account of the visual perception of shape. I’ll close with some remarks on Locke account of time perception. (shrink)

Let me begin with what may seem a very minor point, but one which I think reveals something about how many philosophers today conceive of their subject. During the past few decades, there has been an increasing tendency for references in philosophy books and articles to be formatted in the ‘author and date’ style (‘see Fodor (1996)’, ‘see Smith (2001)’.) A neat and economical reference system, you may think; and it certainly saves space, albeit inconveniencing readers by forcing them to (...) flip back to the end of the chapter or book to find the title of the work being referred to. But what has made this system so popular among philosophers? A factor which I suspect exerts a strong subconscious attraction for many people is that it makes a philosophy article look very like a piece of scientific research. For if one asks where the ‘author-date’ system originated, the answer is clear: it comes from the science journals. And in that context, the choice of referencing system has a very definite rationale. In the progress-driven world of science, priority is everything, and it's vitally important for a career that a researcher is able to proclaim his work as breaking new ground. Bloggs (2005) developed a technique for cloning a certain virus; Coggs (2006) showed how certain bits of viral DNA could be spliced; and now Dobbs (2007) draws on both techniques to develop the building blocks of a new vaccine. The idea is that our knowledge-base is enhanced, month by month and year by year, in small incremental steps (perhaps with occasional major breakthroughs); and in the catalogue of advances, the date tagged to each name signals when progress was made, and by whom. (shrink)

The employment by seventeenth-century natural philosophers of stock theological notions like creation, immensity, and eternity in the articulation and justification of emerging physical programs disrupted a delicate but longstanding balance between transcendent and immanent conceptions of God. By playing a prominent (if not always leading) role in many of the major scientific developments of the period, God became more intimately involved with natural processes than at any time since antiquity. In this discussion, I am particularly concerned with the causal and (...) spatio-temporal relations between God and nature in the seventeenth century as recent scholarship has revealed how dramatically traditional conceptions of these relations were transformed by philosophers and scientists like Descartes, Malebranche, More, and Newton. (shrink)

This essay demonstrates the inadequacy of contemporary substantivalist and relationist interpretations of quantum gravity hypotheses via an historical investigation of the debate on the underlying ontology of space in the seventeenth century. Viewed in the proper context, there are crucial similarities between seventeenth century theories of space and contemporary work on the ontological foundations of spacetime theories, and these similarities challenge the utility of the substantival/relational dichotomy by revealing a host of underlying conceptual issues that do not naturally align with (...) that distinction. (shrink)