Meeting 43

We are using the same link as last spring. If you don’t have it, email us at

DATE: Tuesday, October 26

TIME: 1 PM Princeton time (ET) / 8 PM Bucharest time (UTC+2)

PANEL: Early Modern Correspondence and Open-Ended Inquiries Therein

SPEAKERS: Ovidiu Babeș (University of Bucharest) & Monica Solomon (Bilkent University)

Solid Explanations: Descartes on Mathematically Modelling the Fall of Water

Ovidiu Babeș

My presentation focuses on an episode of mixed-mathematical practice in Descartes’ correspondence: the explanation of the freefall of water. In a 1643 exchange with Constantijn Huygens and Marin Mersenne, Descartes provided a quantitative explanation of the phenomenon of water flowing out of a filled vertical tube. I argue that this episode helps delineate the precise role of mixed-mathematics and natural philosophy in Descartes’ natural scientific practice. I show that his mixed-mathematical explanation is not natural philosophically innocent, making use of many conceptual maneuvers and demonstrative strategies which transgress disciplinary boundaries.

Traditionally, such exercises belonged to mixed-mathematics, a bundle of disciplines that were subordinated mathematics and physics. Mixed-mathematics had little to do with establishing the natural causes of phenomena. One might suspect this is especially true in the case of mixed-mathematics framed as patchy problem-solving, a practice at the heart of Mersenne’s scientific activity in the 1630s and 1640s. After all, Mersenne (and Constantijn Huygens) simply wrote to Descartes asking for a mathematical explanation of the motion of water in freefall. The issue had practical outcomes, and seemed disconnected to any explanatory ambition in natural philosophy.

However, if one studies the development of Descartes’s explanation, the role of natural philosophical concepts and commitments becomes more and more salient. For instance, Descartes packed his physical account of liquidity within his mathematical treatment of the freefall of water, thereby creating important conceptual gaps between how liquid bodies and solid bodies behave in freefall. These gaps resulted in several properties of bodies of liquids which were emergent on the collection of single drops of liquid. Descartes’ systematic natural philosophy does not have the available conceptual resources to account for these emergent properties. Instead, his mixed-mathematical explanation of the flow of water navigated around this constraint by quantitative means. Even if Descartes’ explanation delves into physics as deeply as it can, it does not delve into Descartes’ own physics.

The Hooke – Newton correspondence of 1679

Monica Solomon

I will follow the Hooke-Newton correspondence of 1679 with an eye towards interpretations of the original question posed by Hooke and the follow-up exchanges. Several scholars (De Gandt 1995; Guicciardini, 2005, 2020; Gal 2002;  Marshall Miller 2014; Nauenberg 1994, 1998, 2005; Westfall 1971 to name but a few) have scrutinized this series of correspondence mainly because of the two great (and peculiar) personalities and their priority disputes.

In his first letter, Hooke asks Newton, among other things, for “[his] thoughts of that [hypothesis or opinion of his] of compounding the celestiall motions of the planets of a direct motion by the tangent & an attractive motion towards the centrall body.” Part of the question seems to be that of understanding trajectories as composed of certain motions. It is less clear at which level of generality we should try to answer the question and whether those motions have anything to do with forces (And if so, with which or what kind of forces?)

Throughout the exchange we discover that the original question, which seemed like a well-defined problem in geometry, turns out to be anything but. As we witness Hooke and Newton trying to explain trajectories of bodies under gravity as an attractive force with a center, we also see the difficulties involved in finding the right quantities that make our problems tractable in term of geometrical representations of trajectories. Instead of making Newton or Hooke the characters of this narrative, I will focus on the details of the problem, its interpretation, and possible solutions.

The methodological lesson is that the standards for judging replies as answers or solutions to a specific problem can hardly fit into disciplinary boundaries. Consequently, exchanges such as this one (and correspondence materials more broadly) reveal a far more dynamic disciplinary landscape, one in which physics and mixed-mathematics are sometimes in tension, but never far apart from each other. In particular, a consequence of this analysis is that we should probably give up on describing such processes or series as an example of “mathematization.” 

Meeting 42

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DATE: Tuesday, October 19

TIME: 1 PM Princeton time (ET) / 8 PM Bucharest time (UTC+2)

PANEL: Skepticism and the Passions in Hume’s Philosophy

SPEAKERS: Charles Goldhaber (University of Pittsburgh), Manuel Vasquez Villavicencio (University of Toronto), Anik Waldow (University of Sydney) & Margaret Watkins (Seattle Pacific University)


Spirits and Skepticism in Hume’s Treatments of the Passions 

Margaret Watkins 

In the Treatise, Hume avoids physiological explanations of our perceptions and experiences. But why?  Does physiology simply not fall within the scope of his investigation? Or is he skeptical about the  validity of “natural philosophy” in general? He seems to express such skepticism in “Of the Rise and  Progress of the Arts and Sciences,” and some Treatise passages suggest that attempting to “penetrate  into the nature of bodies” will add little to our understanding of human nature, even as it generates  the possibility of embarrassing mistakes.

Yet we do find a few forays into explicit physiology in the Treatise, as well as language that seems  dependent on contemporary anatomical theories. I will argue that Hume sometimes uses this language literally, and that interpreting him in this way can help us understand aspects of his theory of the  passions. In particular, we tend to read past his references to “animal spirits”—those refined liquids  thought to play a role in voluntary motion, sensation, and passions. If we notice these references at  all, we tend to assume that they are metaphorical, standing in for phenomenological concepts that  might be described in other ways. But sometimes the re-description is not easy at all, which suggests  that Hume is using current theories of anatomy as plausible explanations. A survey of Treatise 2’s  references to animal spirits in comparison with related treatments in the Dissertation on the Passions suggests that Hume recognized that he had been relying heavily on physiology in parts of the Treatise and wished to avoid appealing to this increasingly controversial hypothesis within physical anatomy.  The changes leave him without much explanation for how calm passions motivate or how we can  develop “strength of mind.” But he can still support a deterministic story of the operation of the  passions based on observed correlations, which is what he needs for grounding a theory of moral  judgment where our actions reliably follow those passions that themselves reliably spring from our  character. Hume’s later text supplies this grounding with more skeptical care.  

Hume’s sceptical methodology and the moderation of the passions 

Manuel Vásquez Villavicencio 

David Hume opens A Treatise of Human Nature with a quite surprising affirmation: the philosophy and  the sciences of his time, despite the achievements of the Scientific Revolution, are still in a state of  alarming imperfection. According to him, even “those systems, which have obtained the greatest credit,  and have carried their pretensions highest to accurate and profound reasoning” had only a “weak  foundation” and were the victims of innumerable contradictions (T intro 1). To remedy this situation,  I contend, Hume adopts a new approach to philosophical methodology as the foundation of his  science of human nature. This new approach to philosophical methodology materializes in a sceptical  methodology that Hume presents in the introduction to the Treatise. In this paper, I offer a reconstruction of this methodology to claim that along with considerations about the nature of the  appropriate research objects and explicative strategies for his science of man, Hume includes the  moderation of the passions playing a role in the motivation of philosophical research, especially  curiosity. I claim that this is the case because, although being the essential motor of our epistemic  pursuits, curiosity can become the source of important misconceptions and unpleasant emotional  states such as those which, based on the psychological theories of his time, Hume calls “melancholy”  and “despair.” Hume’s sceptical methodology thus understood is a response to the fact that, according  to him, the philosophers who preceded him did not sufficiently recognize the fundamental role of  human nature in all our epistemic pursuits. For him, I argue, one should give a privileged position to  the study of human nature while recognizing that human nature comprises deeply interwoven  intellectual, emotional, and social aspects.

How not to be an uncouth Monster? Hume and Buffier on Epistemic Role of the Sentiment of Humanity 

Anik Waldow 

Although Buffier is not normally considered an influence on Hume, new evidence suggests that Hume  possessed a copy of Buffier’s Grammaire françoise and had access to his Éléments de metaphysique during  his time in La Flèche. In the Éléments, as well as his influential Traité des premières verités, Buffier uses the  concept of the monster to specify the features of human reason and the need to accept the guidance  of the sentiment humain in the formation of epistemically significant judgements. In this paper I compare  Hume’s famous uncouth monster passage to Claude Buffier’s reflections on monsters as creatures  who lack thoughts and sentiments that other humans can share. The aim of this comparison is to  understand better the account of epistemic judgement Hume continued to rely on even after the sceptical despair of Book I. I argue that this account essentially revolves around the belief that we  have to acknowledge the other as a cognitive equal if we want to enter into an epistemic relationship  with the world. In forming this relationship, the sentiment of humanity and the ability to share  opinions and feelings across different individuals plays the crucial role of enabling the mind to self identify as reasonable and engage in a process of reflective correction. This type of correction is not  dissimilar to the correction that forms part of Hume’s general point of view. It involves the mind’s  readiness to take up different perspectives and to negotiate conflicting evidence by following the  guiding influence of a sentiment common to all. While this interpretation does not provide a solution  to the sceptical challenge, it details the features of a process through which commendable epistemic  judgements can be formed. 

Abstract of “Hume’s Real Riches” 

Charles Goldhaber 

While describing his “fortunes” and “disappointments” in “My Own Life,” Hume draws  attention to a feature of his character which he values above any degree of fame or material wealth.  This is his “naturally…cheerful and sanguine temper” (MOL 6, Mil xxxiv). An “open, social, and  cheerful humour” (MOL 21, Mil xl), Hume explains, buoyed him against reproach and obscurity,  encouraging continued study. He thus views it as “a turn of mind which it is more happy to possess,  than to be born to an estate of ten thousand a year” (MOL 9, Mil xxxvi). Hume’s appraisal here agrees  with the Sceptic’s in his four essays on human happiness: “A propensity to hope and joy is real riches:  One to fear and sorrow, real poverty” (Sc 22, Mil 167). 

Such remarks, I argue, suggest that Hume had a substantive conception of the good life,  consistent with his moral theory: A cheerful disposition is agreeable and useful to oneself and others,  and enables one’s other talents to be so as well. The remarks also raise important questions about the  point of philosophy. I argue that Hume viewed his philosophy as playing a moderate role in the inculcation of a cheerful disposition. Contra interpreters such as James Harris, Hume does not agree  with his Sceptic’s denial that it is “in a man’s power…to correct his temper” (Sc 28, Mil 169).  Philosophy can to a degree “regulate our sentiments” by “plac[ing] opposite characters in proper  contrast” (EHU 1.1, SBN 6), as Hume’s four essays on happiness do. And, in an ironic twist,  philosophy can correct our tempers by revealing its own limitations. This humiliation through  skeptical philosophy can “abate [the] pride” of those “inclined, from their natural temper, to  haughtiness and obstinacy,” encouraging an open and social “modesty” (EHU 12.24, SBN 162).


Meeting 41

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DATE: Tuesday, October 12

TIME: 1 PM Princeton time (ET) / 8 PM Bucharest time (UTC+2)

PANEL: Newton on Hypotheses

SPEAKERS: Areins Pelayo (University of Illinois) & Kirsten Walsh (University of Exeter)


The Metaphysical and Empirical Criteria in Newton’s Hypotheses

Areins Pelayo

Newton disdained ‘Cartesian hypotheses,’ yet admitted that hypotheses were useful if examinable  by experiments. Throughout his career, Newton tinkered with two theses: the corpuscularity of light and  the aether—two ideas that some commentators agree Newton treated as hypotheses. In this paper, I  propose six implicit criteria (four metaphysical and two empirical) that these two hypotheses satisfy,  which makes sense of Newton’s conflicting remarks on hypotheses. My proposal combines the partial  pictures of Cohen (1999, 1969), Dobbs (1991), Janiak (2008), Shapiro (1993), and Walsh (2014). The  four metaphysical criteria are (i) Non-contradiction, (ii) Parsimony, (iii) Mechanism, and (iv) Divine  Conformity. The two empirical criteria are (v) the Analogy of Nature and (vi) Experiment. I pay special  attention to how Newton’s theology and alchemy inform these criteria. For instance, because God could  not directly cause gravity, Newton speculated that an aether was its cause. I thus show, with these six  criteria, why it made sense for Newton to reject Cartesian hypotheses.

The Instrumental Roles of Newton’s Optical Hypotheses

Kirsten Walsh

Early modern experimental philosophers often appear to commit to, and utilise, corpuscular and mechanical hypotheses. This is somewhat mysterious: such hypotheses frequently appear to be simply assumed, odd for a research program which emphasises the careful experimental accumulation of facts. Isaac Newton was one such experimental philosopher, and his optical work is considered a clear example of the experimental method. Focusing on his optical investigations, I identify three roles for hypotheses. Firstly, Newton introduces a hypothesis to explicate his abstract theory. The purpose here is primarily to improve understanding or uptake of the theory. Secondly, he uses a hypothesis as a platform from which to generate some crucial experiments to decide between competing accounts. The purpose here is to suggest experiments in order to bring a dispute to empirical resolution. Thirdly, he uses a hypothesis to suggest an underlying physical cause, which he then operationalises and represents abstractly in his formal theory. The second and third roles are related in that they are both cases of scaffolding: hypotheses provide a temporary platform from which further experimental work and/or theorising can be carried out. In short, the entities and processes included in Newton’s optical hypothesis are not simply assumed hypothetical posits. Rather, they play instrumental roles in Newton’s experimental philosophy.

Meeting 40

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DATE: Tuesday, October 5

TIME: 1 PM Princeton time (ET) / 8 PM Bucharest time (UTC+2)

PANEL: Émilie du Châtelet’s Epistemic Foundations

SPEAKERS: Clara Carus (Paderborn University), Anne-Lise Rey (Université Paris Nanterre) & Aaron Wells (Paderborn University)


Émilie du Châtelet’s Account of Knowledge in Light of her Determination of ‘a Being’

Clara Carus

In this paper I aim to shed light on Du Châtelet’s account of knowledge through her understanding of ‘a being’. In paragraph 35 of her Institutions Physiques Du Châtelet determines a being [un Etre] as that which can exist and whose determinations do not entail a contradiction. Along with her predecessor Wolff, she deems the determination of a being (a ‘thing’ in Wolff) to rest on a rational principle of non-contradiction: if I can prove that an idea is free of contradiction it is possible and thus a being – if an idea entails a contradiction it is a chimera. A being thus need not be actually physically present to be a being – its beingness rests solely on its possibility on the basis of non-contradiction of its determinations. The actuality of a being on the other hand is explained on the basis of the principle of sufficient reason. Du Châtelet’s understanding of a being in its possibility and in its actuality subsequently serves as the foundation of her definition of essence, attributes and modes, as well as substance and paints a clear picture of her account of knowledge of the natural world, as I will present in this paper. 

Du Châtelet’s epistemic situation : Power and limits of knowledge

Anne-Lise Rey

The project of this intervention is to question the epistemic status of the knowing subject in “Institutions de physique”. It is a question of asking whether it stems from a form of epistemic impotence specific to our condition of being human endowed with a limited understanding or if this limitation is not, on the contrary, the starting point of a redefinition of our power to know.

Science and the Principle of Sufficient Reason: Du Châtelet’s Departures from Wolff

Aaron Wells

Emilie Du Châtelet takes the principle of sufficient reason to be one of the two foundations of all our reasoning. In this she agrees with Wolff, who is widely agreed to be a key influence on the substance–accident–mode ontology of her Institutions. So we might expect that Du Châtelet understands the principle of sufficient reason (PSR) along basically Wolffian lines.

In this talk I lay out some ways in which, to the contrary, Du Châtelet breaks with Wolff regarding the scope and epistemological content of the PSR. I also suggest, in a more promissory way, that these differences have major consequences for how Wolff and Du Châtelet conceive of the relationship between the PSR and science. A final goal of the paper is to give a clearer account of some basic features of Du Châtelet’s PSR.

First, regarding scope: Wolff takes the PSR to range over all possible properties, including simple positive properties that exist necessarily and immutably. These properties, roughly, are the building blocks of the essences of possible substances. Therefore, Wolff’s PSR governs necessary and not just contingent features of the world. Du Châtelet agrees with Wolff that there are some necessary and immutable simple positive properties. However, she takes the PSR to hold only in the realm of the contingent. Moreover, her PSR ranges in the first instance over propositions or judgments, and only indirectly, insofar as these propositions are true, over their referents).

Second, regarding epistemological content: Wolff takes the PSR to guarantee a grasp of real grounds: objective properties, and dependence relations among them, that our cognitive faculties can track. These dependence relations are transitive. By contrast, Du Châtelet takes the PSR to guarantee the possibility of answers to certain questions (namely how- and why-questions); these answers enable understanding. While sometimes the means to answering these questions will appeal to real grounds, such as causes, this is not always true. Strictly false hypotheses, or merely ideal mathematical claims, can enable understanding. When understanding is indexed to success in answering how- and why-questions, rather than to real grounding relations such as causation, there is no reason to expect that it will be transitive. 

To gesture at some broader implications: Wolff famously defines science as “the habit of demonstrating propositions, i.e., the habit of inferring conclusions by legitimate sequence from certain and immutable principles;” these principles typically involve real definitions that express essences (Discursus Praeliminarius §30). Wolff’s PSR plays a key role in backing his ambitious conception of science. The PSR is needed to prove that there are real essences, and that we can represent these essences and their connections in a unified deductive scientific theory. By contrast, since Du Châtelet’s PSR only pertains to the contingent, ranges over propositions rather than their referents, and fails to guarantee a grasp of transitive real grounding relations, it is not apt to back such an ambitious conception of science. And indeed, Du Châtelet does not advocate an ambitious Wolffian conception of science and explanation. Fully exploring how and why she does so, however, is a project for another time. 

Meeting 39

We are using the same link as last spring. If you don’t have it, email us at

DATE: Tuesday, September 28

TIME: 1 PM Princeton time (ET) / 8 PM Bucharest time (UTC+2)

PANEL: Theories of Mental Representation in Early Modern Philosophy

SPEAKERS: Manuel Fasko (University of Basel), Lauren Slater (Birkbeck College), Peter West (Durham University)

CHAIR: Patrick Connolly (Lehigh University)


This panel explores treatments of mental representation in Early Modern philosophy. By considering representation as it was understood by three thinkers – Descartes, Berkeley, and Anton Wilhelm Amo – this panel will explore the various ways the Early Moderns thought one thing could represent another. In doing so, the panel will show that ‘representation’, in Early Modern philosophy, is a complex issue. For instance, while some thinkers werecommitted to a simple, univocal notion of representation, others came to appreciate that there is more than one way in which things might represent. For some thinkers, this was even manifested in a terminological distinction; between representation and signification.

On a typical reading of Descartes, ideas represent their objects in the external world in virtue of a causal (albeit mysterious) relation that holds between them. However, there are also signs that Descartes thought the relation between ideas and objects is more like the relation between words and their meanings. Berkeley, in contrast, assumes that representation must involve resemblance. It remains unclear why he took this to be the case and, moreover, why he seems to attribute this view to his opponents, including Locke. Finally, Amo maintains that the role of ideas is to stand in for and present that which is absent. For instance, Amo argues that there are no ideas in the mind of God since nothing is absent from his understanding. However, it is not clear how Amo thinks ideas present that which is absent. Is it the same way that a portrait might be said to stand in for its subject or more like the way a politician stands in for (and thereby represents) her constituency?

A consideration of the various ways in which this question was addressed during the period will also deepen our understanding of the important Early Modern concept of ‘ideas’: mental objects which, in some form or another, represent the external world to us.

Re-presenting Representation: Cartesian Ideas and their Objects

Lauren Slater

In the preface to the Meditations, Descartes distinguishes between ideas taken in the material sense and ideas taken in the objective sense. I argue that this distinction helps to uncover an ambiguity in the word ‘representation’ for Descartes. Sometimes, Descartes seems to understand ‘representation’ as a notion of presentation: a presentation of content in the mind. At other times, Descartes seems to use ‘representation’ in a more everyday sense: the sense in which representation is a relation that holds between ideas and external features and objects. I then turn my attention to sensory ideas and their representational status; since, out of all the kinds of ideas, they seem the most likely to represent the external world to us. I argue that Cartesian sensory ideas do represent (in the relational sense) external objects and features, even though they bear no resemblance to them. This is possible due to the language-like connection between the body and the mind that is instituted by God.

“No representation without resemblance: Berkeley’s resemblance thesis and the necessary conditions for representation

Manuel Fasko

While we also ought to distinguish two kinds of representation in Berkeley’s writings, I will not focus on how words ‘represent’ things. Rather, I will focus on the (representational) relation between our ideas and the part of reality they are ideas of (i.e. the part of reality they represent). It is widely agreed that Berkeley is convinced that resemblance is necessary for representation. However, there is currently no (exhaustive) list of all the further necessary conditions that representation requires. I argue that there are in fact three necessary conditions which this kind of representation requires. First, there ought to be an act of perceiving (in order to have something we can have an idea of). Second, an act of imagining or remembering is necessary (by means of which an idea of something is generated). Third, representation necessarily requires resemblance (i.e. our idea of A is only one of A and not of B if it resembles A). Yet, on a closer look this third condition, in turn, requires two sub-conditions because the relation of resemblance only obtains if i) there is an agreement between the relata in at least one respect and ii) there is an act of comparing.

Amo on Ideas and Representation

Peter West

Prior to Anton Wilhelm Amo’s writing in the 1730s, it is possible to identify two dominant accounts of the way an idea represents its object. First, a causal (or quasi-causal) theory which has been attributed to Descartes and other Cartesians. Second, a resemblance theory which can plausibly be attributed to Berkeley and other critics of the epistemology espoused in Locke’s Essay. However, in his Inaugural Dissertation (published in 1734) Amo characterises an idea as something that represents by means of standing in for something which is absent. I argue that, in doing so, Amo offers a novel theory of representation that requires neither causation nor resemblance. Instead, for Amo, ideas play a specific functional role in the mind (comparable to the role played by sensations in the body) by means of which they represent – that is, stand in for – their objects. This explains why Amo argues that there are no ideas in the mind of God; there being nothing absent in God’s mind, it would not be possible for something to play this functional role.

Meeting 38

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DATE: Tuesday, September 21

TIME: 1 PM Princeton time (ET) / 8 PM Bucharest time (UTC+2)

PANEL: Robert Boyle: Philosophy and Experiment

SPEAKERS: Marina Paola Banchetti-Robino (Florida Atlantic University), Michelle DiMeo (Science History Institute), William Eaton (Georgia Southern University)


Fish, Function, and Philosophy: The Petty/Boyle Dissections

William Eaton

A turning point in the history of science occurred in the cold, damp, conditions of Dublin during the winters of 1653, when William Petty painstakingly taught Robert Boyle anatomy. Together they dissected a few human cadavers, dogs, pigs, and a lot of fish. Up to that point, Boyle’s scientific work had been largely theoretical. He read scientific books up to 12 hours a day, suffering headaches from reading so much. But this work was different. It was hands-on applied Baconiansm. Boyle would later claim that he learned more about the universe cutting up fish with Petty than in all the books he had ever read. Though seldom given much attention due to his spectacular achievements at Oxford just a few years later, I think we can learn a lot from these early experiments. They solidified Boyle’s endorsement of the mechanical philosophy and influenced his approach to science (not just his chymistry, but his work in pneumatics, medicine, and other areas). He learned firsthand the need for more than one experiment, the value of unsuccessful experiments, the fact that individual specimens and background conditions vary greatly, to not rely on authority for scientific truth, that the best authority is your own experience in a careful observation, and that empirical evidence should be the deciding factor between completing mechanical explanations. Boyle’s progress in science accelerated when he started using empirical evidence to decide between competing mechanical explanations. I argue that this occurred for the first time when he realized Harvey’s mechanical explanation of the circulation of the blood was correct, and Descartes’s equally mechanical theory was mistaken. Under Petty’s guidance he saw with his own weak eyes that the heart is more like a pump than it is a furnace. Pumps over percolation, in the cold Irish winter.

The Role of Negative-Empirical Concepts in Sennert and Boyle

Marina Paola Banchetti-Robino

This presentation examines the role played by negative-empirical concepts in the chymical philosophy of Daniel Sennert (1572-1637), which mediates between the strictly Aristotelian and the strictly Democritean theories of matter by modifying the notion of substantial form and by employing an operational definition of substances as the limits attained by the analytical method of the laboratory. Sennert appropriates this ‘negative-empirical conception of chemical substance’, as Bernadette Bensaude-Vincent and Isabelle Stengers have called it, from the tradition of Scholastic alchemy.  Sennert’s work anticipates the important role that the idea of negative-empirical concepts would play in later early modern chemistry, particularly in the chymical philosophy of Robert Boyle.  In fact, negative-empirical concepts would acquire particular explanatory power in one of Sennert’s most influential experimental procedures, the ‘reduction to the pristine state’, an experiment that was later appropriated by Boyle to provide empirical support for his mechanistic notion of essential form.  The paper will show that, far from being insignificant in the history of early modern chymistry, the work of Sennert had important influence on later chymists and, in particular, on the work of Robert Boyle who adopted both the experimental procedure of reduction to the pristine state and a negative-empirical conception of chymical atoms to support a mechanistic but non-reductionist conception of chemical substances.

Boyle’s Medical Recipes as Experiments Proving the Corpuscular Philosophy

Michelle DiMeo

This paper will focus on several interrelated medical texts that Boyle published in the final years of his life. By applying Boyle’s methods for the experimental process onto his medical recipe trials, I show how Boyle used practical experiments like recipes to prove his theories on the corpuscular philosophy. Boyle’s thoughtful articulation of method provides a rare view into how natural philosophers contextualized the personal experience and direct observation used in “household science” within developing theoretical frameworks.  

Meeting 37

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DATE: Tuesday, September 14

TIME: 1 PM Princeton time (ET) / 8 PM Bucharest time (UTC+2)

PANEL: Locke’s Theory of Personal Identity in Context

SPEAKERS: Anita van der Bos (University of Groningen) & Michael Jacovides (Purdue University)


The Implications of Locke’s Theory of Personal Identity on the Belief of the Resurrection of the Same Body: The Debate between Whitby and Bold (download handout)

Anita van der Bos

Locke’s distinction between ‘man’, ‘person’, and ‘body’ was a big innovation in the seventeenth century. His theory of personal identity was the centre of many debates and is still discussed today. In the talk I’ll be giving today I want to familiarize you a bit with a lesser known debate, the one between Daniel Whitby and Samuel Bold. I’ll be focussing on Whitby’s critique of Locke. I intend to show that Whitby fails to understand what Locke meant with ‘person’, ‘man’, and ‘body’. Whitby’s interchangeable use of Lockean terms makes his account of the resurrection contradictory and problematic. It also shows that he and Locke are talking past one another.

Hobbes’s Influence on Locke’s Theory of Personal Identity

Michael Jacovides

According to Locke, in order to judge identity “aright, we must determine what Idea the Word it is applied to stands for: It being one thing to be the same Substance, another the same Man, and a third the same Person.” Hobbes writes, “we must consider by what name any thing is called, when we enquire concerning the Identity of it; for it is one thing to ask concerning Socrates whether he be the same Man, and another to ask whether he be the same Body.” I want to draw out the influence of Hobbes’s account of identity in de Corpore on Locke’s theory of identity and the influence of his discussion of persons in Leviathan on Locke’s theory of persons. This will help us understand Locke’s doctrine that sameness of body requires sameness of all corporeal constituents, explain his mention of sources of motion in his treatment of the identity of artifacts and living things, and, most importantly, clarify the role of composition in his account of identity. I’ll show how Locke’s theory of personal identity is, in the first instance, a Lockean solution to a Hobbesian problem. I close by explaining a mysterious but illuminating argument against Hobbes’s philosophy of mind in Locke’s chapter on personal identity.

Meeting 36

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DATE: Tuesday, May 4

TIME: 1 PM Princeton time (EST) / 8 PM Bucharest time (GMT+2)

PANEL: Plants in Early Modern Natural Philosophy: Mechanico/Chymical Investigations

SPEAKERS: Oana Matei (Vasile Goldis Western University of Arad & University of Bucharest) and Fabrizio Baldassarri (Ca’ Foscari University of Venice):


Particles and Spirits: Fundamental Processes of Nature in Mid-Seventeenth Century Studies of Plants

Oana Matei

Gardening, plant cultivation, experiments that involve vegetables, trees, herbs and flowers do not seem, at first glance, to be very philosophical. However, in England, in the second part of the seventeenth century, a significant number of natural philosophers (such as Robert Boyle, John Evelyn, Kenelm Digby, Nehemiah Grew, John Woodward) were actively involved in such activities and were not interested just in the utility that such experiments could bring. Their concern went even beyond the study of external and internal features of plants.  I propose to look at experiments with plants in the second part of the seventeenth century as attempts to investigate the fundamental processes of nature. Although sometimes with different backgrounds, theoretical assumptions and metaphysical allegiances, in their endeavours, naturalists used plants as laboratories that illustrate processes of nature and where fundamental transformations take place and can be investigated. Apart from the instrumental use of plants, mid-seventeenth century natural philosophers adopted an operational vocabulary emerged from experimental practices and that, in spite of their different theoretical presuppositions, allowed them to communicate experimental results and knowledge. To support this claim, I will discuss the cases of John Evelyn and John Beale in relation to other early fellows of the Royal Society, such as Robert Boyle and Kenelm Digby.

Herba Impatiens, Mimosa, and Tulips: Plants in Cartesian Mechanical Philosophy of Nature (1618-1662)

Fabrizio Baldassarri

In this paper, I aim to explore a crucial section of the study of botany, namely the mechanical understanding of plant life that developed in the Cartesian context. In presenting the case of a few specimens discussed by Descartes and early Cartesians, I show their attempts to provide a complete mechanization of their nature—namely the structure, functioning, scents, and flavor of plants. This is particularly interesting, insofar as Descartes’s natural philosophy has a theoretical and speculative approach to nature, devising a general framework in which all bodies could be encompassed, with little discussions of particular cases. The need to deal with such cases, generally triggered by Mersenne’s curiosity, at least for the case of Descartes himself, is therefore meaningful from both a methodological and a natural philosophical points of view. Embedded within mechanical interpretations of the life of plants, I present Descartes’s discussion of the ambretta flower and the Mimosa pudica, comparing this investigation with Beeckman’s description of the herba impatiens, another type of noli-me-tangere; then, I focus on Regius’s mechanical description of the Mimosa pudica; finally, I deal with Florent Schuyl’s description of tulips. I also show how much this mechanical approach to vegetal bodies influenced the science of plants in the second half of the seventeenth century.

Meeting 35

We are using the same link as in the fall. If you don’t have it, email us at

DATE: Tuesday, April 27

TIME: 1 PM Princeton time (EST) / 8 PM Bucharest time (GMT+2)

PANEL: Leibniz on Laws and Spiritual Causation

SPEAKERS: J. Brian Pitts (University of Lincoln, University of Cambridge, University of South Carolina) & Andrew Chignell (Princeton University)


The Mind-Body Problem and Conservation Laws: An Outline in Light of the Growth of Physical Understanding

J. Brian Pitts

The success of science, especially physics, is often invoked as contrasting with the degeneration of world-views involving immaterial persons, whether purely spiritual or embodied.  A perennially popular question from the 17th century to the 21st is how, if at all, human minds can interact with bodies in light of physical conservation laws.  (Recently popular property dualism, if not epiphenomenalist, faces a similar question.)  This question has survived and helped to bring about a transition from a time in which educated opinion generally took interactionist mind-body dualism for granted to a time in which mind-body interactionism is widely rejected.  Leibniz was an early proponent of this objection in defense of a non-interactionist dualist view, pre-established harmony, a view popular in 18th century Germany for a time before the recovery of interactionism. 

This work aims to survey how this conservation law issue has been treated over the centuries, especially how it did (or did not) reflect relevant theoretical and experimental knowledge pertaining to conservation laws, as well as how well it worked as an argument (which, e.g., ought not to beg the question).  Leibniz’s Theodicy presents his objection as due to a growth in physical knowledge about conserved quantities since Descartes’s day: whereas Descartes accepted a conserved quantity of motion, Leibniz accepted a conservation of a directed vector quantity (momentum) as well as vis viva (an ancestor of energy), which was controversial.  In the 19th century, energy conservation was accepted.  In the later 19th century with the rise of electromagnetic waves, the handful of global conservation laws associated with point particles acting at a distance was replaced (in serious physics) with local conservation laws for each part of the world separately; in favorable circumstances the local laws can be integrated into a global law.  The local laws are (in those favorable circumstances) logically stronger, but they also permit milder failure modes.  In the 19th and 20th centuries, a connection between conserved quantities and symmetries of physical laws came to be understood, especially in connection with the principle of least action culminating in Noether’s work in 1918, which also included a converse:  a symmetry implies a conserved quantity and vice versa.  Also quantum mechanics appeared, with unclear implications.

Besides Leibniz, the issue engaged Euler, Kant, Maxwell, Helmholtz, Broad, and others, and continues to appear frequently in the contemporary philosophy of mind.  While the understanding available from physics has grown or in some cases changed, the philosophical treatment has remained largely static in roughly the physics of the 1860s among both friends and foes of interactionist dualism (with occasional exceptions).  General Relativity, now over a century old, also affects the discussion, albeit not in ways previously proposed.  This paper aims to survey the growth of knowledge on the conservation law mind-body issue. 

Leibniz on Miracles in the Best Possible World 

Andrew Chignell

Leibniz makes repeated efforts to stretch the frame of his rationalist-determinist picture to accommodate the traditional portrait of God as miraculously intervening in the natural world.  His goal is effectively to save the appearances of religious doctrine (or at least avoid direct conflict with biblical orthodoxy) while sticking to his metaphysical principles.  In this paper I consider Leibniz’s way of putting these two commitments together and argue that it is coherent: he can have his miracle doctrine and eat his deterministic cake too.  However, the combination results in a certain amount of epistemic inhospitableness, at least for finite minds.  This raises questions about whether it could really obtain in the best possible world. 

Meeting 34

We are using the same link as in the fall. If you don’t have it, email us at

DATE: Tuesday, April 20

TIME: 1 PM Princeton time (EST) / 8 PM Bucharest time (GMT+2)

PANEL: Hadot, Spiritual Exercises, and Philosophy as a Way of Life

SPEAKERS: Sorana Corneanu (University of Bucharest), Dana Jalobeanu (University of Bucharest), Paul Lodge (University of Oxford)


Reading, meditation and enactment: Hadot’s formative exegetics

Dana Jalobeanu (University of Bucharest)

In my paper I am trying to reassess some of Pierre Hadot’s contributions to the history of philosophy from the perspective of the ‘practice turn’ we are all living through in the later years (especially those of us dealing with history of science). I will be looking at a particular class of spiritual exercises (“imaginative spiritual exercises”) and show what we gain if we think of them as recorded (philosophical) practices. 

“Spiritual exercise” is an umbrella term designating a wide array of practices of reading, research and meditation having in common a personal, existential engagement, described in terms of an imaginative, emotional and cognitive repositioning of the practitioner with respect to “the whole” (Nature, or Universe). Spiritual exercises constitute, according to Hadot, one of the trademarks of a philosophical way of life. Much has been said about these spiritual exercises, and Hadot followers and critiques attempted to define, classify and describe them. So, in looking at a particular class of spiritual exercises I am following in the footsteps of those who attempted to clarify and classify spiritual exercises. 

Meanwhile, I also intend to address a more general set of problems having to do with our ways of reading and interpreting texts. I begin with Hadot’s proposal for a “formative exegetics,” i.e., a way of reading based on two guiding principles: 1) ancient texts record philosophical practices (spiritual exercises) and 2) these recordings are done through a process of “bricolage” through which one re-assembles set building blocks (references, quotes, formulas, topics coming from a limited number of sources). Reading becomes thus a process of disentangling, from the bricolage, the philosophical practices (i.e., spiritual exercises) recorded in a text.  In my talk I will try to put these principles at work, showing on a set of choice examples what are the steps of Hadot’s  “formative exegetics,” and what insights do we gain if we read texts in this way. 

Lived logic: the discipline of assent and the cure of error

Sorana Corneanu (University of Bucharest)

Philosophy as a way of life, Hadot tells us, is the counterpart of theoretical philosophical discourse. If, according to the Stoics, for example, the latter is comprised of logic, physics and ethics as bodies of arguments, the former consists in living logic, physics and ethics, i.e., in engaging in the types of practical exercises that will train us to think and speak well, to contemplate the cosmos, and to engage in just actions. In this talk, I would like to take up the ‘lived logic’ component of the art of living as Hadot construed it. What does it mean for logic to be lived? In other words, how are we to understand the idea that the stuff of logic – our thinking, judging, reasoning, arguing, etc. – can be taken up as a transforming practice? Moreover, is this supposed to be a purely intellectual practice, or are there crossovers with the other quarters of the mind, such as the passions and the imagination? I propose to investigate these questions with the help of Epictetus on the discipline of assent in the Discourses and Galen on the cure of error in The passions and errors of the soul, to which I will add some comments on the historiographic and conceptual gains that looking at logic as a practice can afford. 

Philosophy as a 21st Century Way of Life?

Paul Lodge

The expression ‘philosophy as a way of life’ emerged in the writings of Pierre Hadot primarily as a tool for making sense of some of those who are standardly referred to as ‘ancient philosophers’. Perhaps unsurprisingly, however, it has since served as a source of inspiration for how philosophy might be conceived, and indeed rejuvenated, today. After introducing a recent project which has this as its express aim, I discuss an article by two of the people involved in it, Stephen Grimm and Caleb Cahoe, in which an attempt is made to articulate three principles that should underwrite such a conception.