My main interests in philosophy lie in a general area that one might call 'historically informed and inspired philosophy' by which I mean a kind of philosophy that is grounded in the ideas and questions of philosophers of the past but also contributes to the contemporary philosophical debate. My motivation to engage in a dialogue with these historical figures is not mere historical curiosity but primarily the belief that this is an invaluable tool for doing worthwhile philosophical research in general. For starters, all philosophy, including contemporary philosophy, is, in some sense, history of philosophy, in that it involves close analysis of, and critical engagement with, extant texts written by other philosophers. In this respect, it does not make much of a difference whether the author of the text in question is still alive, or has been dead for several hundred years. And, arguably, by not restricting one’s reading to texts that were written within the last couple of decades or so, one vastly increases one’s chances of finding works to grapple with that are both truly excellent and exciting, given one’s particular philosophical tastes and sensibilities. Second, most of the central philosophical questions and problems that we are thinking about today did not just spring from our heads yesterday like Athena from the head of Zeus, but developed over time and thus possess a rich history. Philosophy does not happen in a vacuum. To my mind, the presuppositions and implicit assumptions that are built into many philosophical questions and problems can only be adequately understood if their historical lineage is sufficiently appreciated. And since understanding the presuppositions of a problem is a necessary condition for understanding the problem itself, and since understanding a problem is a necessary condition for making progress towards solving it, I take a certain amount of historical work to be an essential component of any kind of responsible philosophical research. Last but not least, thinking oneself into the arguments and systems of past philosophers keeps one’s mind young and agile, and prevents one from taking one’s own perspective too seriously. There are many different legitimate and fruitful ways to approach the ‘big questions’, and it is healthy to remember that. In this respect, doing history of philosophy is similar to traveling to foreign lands, and experiencing different cultures. It is a wonderfully enjoyable antidote to closed-mindedness and parochialism.
The historical period in which I feel most at home in ranges from the mid-17th to the early 20th century. Most of my work so far has been on various aspects of the theoretical philosophy of Gottfried Wilhelm Leibniz and Immanuel Kant. But my favorite dead interlocutor is probably Arthur Schopenhauer. I also have a long-standing side-interest in the history of aesthetics, and, more recently, have begun to engage more seriously with the history of ethics, in particular, the history of ethical theories that centrally thematize compassion in some way (be it positively or negatively), as well as with various existentialist thinkers from the 19th and early 20th century. Last but not least, I love animals, and so I work on animal ethics too.
The World According to Kant — Appearances and Things in Themselves in Critical Idealism, Oxford University Press (2021). Online Access!
The World According to Kant offers an interpretation of Immanuel Kant’s critical idealism, as developed in the Critique of Pure Reason and associated texts. Critical idealism is understood as an ontological position, which comprises transcendental idealism, empirical realism, and a number of other basic ontological theses. According to Kant, the world, understood as the sum total of everything that has reality, comprises several levels of reality, most importantly, the transcendental level and the empirical level. The transcendental level is a mind-independent level at which things in themselves exist. The empirical level is a fully mind-dependent level at which appearances exist, which are intentional objects of experience. Empirical objects and empirical minds are appearances, and empirical space and time are constituted by the spatial and temporal determinations of appearances. On the proposed interpretation, Kant is thus a genuine idealist about empirical objects, empirical minds, and space and time. But in contrast to other intentional objects, appearances genuinely exist, which is due both to the special character of experience compared to other kinds of representations such as illusions or dreams, and to the grounding of appearances in things themselves. This is why, on the proposed interpretation, Kant is also a genuine realist about empirical objects, empirical minds, and empirical space and time. This book develops the indicated interpretation, spells out Kant’s case for critical idealism thus understood, pinpoints the differences between critical idealism and ‘ordinary’ idealism, such as Berkley’s, and clarifies the relation between Kant’s conception of things in themselves and the conception of things in themselves by other philosophers, in particular, Kant’s Leibniz-Wolffian predecessors.
Errata: Given that during every read-through (of which there were many) before sending the final draft of the book to the publisher, I found several typos and errors, I cannot say that I am surprised that these unpleasant discoveries have continued even after the publication of the book. So far, no major error has surfaced but even the small ones bug me quite a bit. And so I decided to maintain a running list of errata plus corrections on my website, which can be found here. If you discover additional errors, typos, or unfortunate formulations, I would be grateful to hear from you.
Articles and Chapters
“The Labyrinth of the Continuum: Leibniz, the Wolffians, and Kant on Matter and Monads,” in Karl Schafer and Nicholas Stang (editors), The Sensible and Intelligible Worlds: New Essays on Kant’s Metaphysics and Epistemology, Oxford/New York: Oxford University Press (2022), 185–216. Download!
The problem at the center of this essay is how one can reconcile the continuity of space with a monadological theory of matter, according to which matter is ultimately composed of simple elements, a problem that greatly exercised Leibniz, the Wolffians, and Kant. The underlying purpose of this essay is to illustrate my reading of Kant’s philosophical development, and of his relation to the Wolffians and Leibniz, according to which, (a), this development was fueled by ‘home-grown’ problems that arose within the framework of the Wolffian philosophy from which Kant started out, and, (b), on his journey to critical idealism, Kant gradually moved away from Wolffianism, but closer to Leibniz, which, however, he came to realize only some years after the publication of the Critique of Pure Reason. This reading is illustrated by showing that the problem of how to reconcile the continuity of space with a monadological theory of matter is a problem that Kant inherits from Leibniz and the Wolffians, in whose thinking it already plays an important role, that Leibniz’s mature solution to the problem differs markedly from the Wolffian solution, and that Kant’s early, pre-critical solution is largely Wolffian, while his later critical solution is largely Leibnizian, as he himself notes with gleeful satisfaction. The discussion also reveals that this problem is one of the key problems that fueled Kant’s philosophical development and, eventually, led him to the discovery of transcendental idealism.
“Kant on the (alleged) Leibnizian misconception of the difference between sensible and intellectual representations,” in Brandon Look (editor), Leibniz and Kant, Oxford/New York: Oxford University Press (2021), 177–210. Download!
Kant attacks the Leibnizians on various fronts but the objection that occurs most frequently in his writings is that they are committed to an untenable conception of the relation between sensible and intellectual representations. They regard the difference between intellectual and sensible representations as a merely ‘logical’ difference that concerns their form, namely, their different degrees of distinctness, while in truth it is a difference in kind that concerns their nature, origin, and content. In the first part of this essay, I provide a detailed reconstruction of what exactly this objection amounts to, and show why Kant takes this misconception to be so significant that he keeps coming back to it over and over again. The misconception is so significant because virtually all of the other mistaken doctrines of the Leibnizians can be traced back to it. Several commentators have argued that Leibniz is not guilty of the confusion of sensible and intellectual representations that Kant accuses him of. But this does not automatically clear him from all the other errors that Kant takes to be closely connected with this confusion. In the second part of this essay, I take a look at Leibniz's theory of confused perceptions and examine whether he is committed to one of these errors, namely, the view that we could learn something about things in themselves by experience if our senses were acute enough or our powers of 'disfusing' perceptions were strong enough.
“Finite minds and their representations in Leibniz and Kant,” in Sally Sedgwick and Dina Edmundts (editors), Internationales Jahrbuch des Deutschen Idealismus/International Yearbook of German Idealism (2019), 47−80. Download!
This essay examines some of the ways in which the assumption of the essential finitude of the human mind, in contrast to the infinitude of God’s mind, bears on Leibniz’s and Kant’s accounts of our representational capacities. This examination reveals several underappreciated similarities between their views, but also some notable differences that help us pinpoint where and in what ways Kant departs from his celebrated predecessor. The fruits of this examination are a better understanding of Kant’s conception of the discursivity of our understanding, his account of the difference between concepts and intuitions, and the particular flavor of his idealism.
“The synthetic nature of geometry, and the role of construction in intuition,” in Stefano Bacin, Alfredo Ferrarin, Claudio La Rocca, and Margit Ruffing (eds.), Kant und die Philosophie in weltbürgerlicher Absicht: Akten des XI. Internationalen Kant Kongresses 2010 in Pisa, Volume V, Berlin/New York: Walter de Gruyter Verlag , 89–100. Download!
Most commentators agree that (part of what) Kant means by characterizing the propositions of geometry as synthetic is that they are not true merely in virtue of logic or meaning, and that this characterization has something to do with his views about the construction of geometrical concepts in intuition. Many commentators regard construction in intuition as an essential part of geometrical proofs on Kant’s view. On this reading, the propositions of geometry are synthetic because the geometrical theorems cannot be proved in purely conceptual or logical terms. Other commentators see the main role of pure intuition and the figures constructed in pure intuition in that they provide a model for Euclidean geometry. On views of this kind, the propositions of geometry are synthetic because the geometrical axioms are substantive truths about one of our forms of intuition. On the interpretation proposed in this essay, what Kant means by claiming that the propositions of geometry are synthetic is not only that the Euclidean axioms and theorems cannot be reduced to tautologies or logical truths, but also that they apply to really possible objects. Construction in intuition plays no essential role in (what we now call) ‘pure’ geometry on Kant’s view. But the fact that the concepts of geometry can be constructed in intuition is of crucial importance in the context of Kant’s transcendental philosophy of geometry, because, among other things, it allows him to explain how Euclidean geometry is possible as an a priori synthetic science in the sense just indicated.
“Kant, the Leibnizians, and Leibniz,” in Brandon Look (editor), The Continuum Companion to Leibniz, London/New York: Thoemmes Continuum Press (2011), 289–309. Download!
A popular story about Kant's relation to Leibniz presents Kant as a Leibniz-Wolffian by education who, inspired by his encounter with the teachings of Newton and Hume, took on the project of reconciling Leibniz-Wolffian metaphysics with Newtonian science and of responding to epistemological skepticism, a project that led him further and further away from his Leibniz-Wolffian roots and culminated in the total rejection of the Leibniz-Wolffian philosophy in the Critique of Pure Reason. In this essay, four shortcomings of the popular story are identified and several suggestions are made about how to amend and expand the story in order to overcome these shortcomings. Furthermore, some of the most important Leibnizian doctrines that influenced Kant are collected and their role in Kant's philosophy is discussed.
“Disentangling Leibniz’s views on relations and extrinsic denominations,” Journal of the History of Philosophy 48.2 (2010): 171–205. Download!
Most commentators agree that Leibniz advocates some version of a doctrine of the ideality or reducibility of relations, but there is considerable disagreement about what exactly this doctrine means. I argue that Leibniz’s views on relations are more complex than has been previously appreciated, and that, despite some ‘reductionist’ strands in Leibniz’s position, it is seriously misleading to describe him as a reductionist about relations without adding some important qualifications. The complexity of Leibniz’s views on relations tends to be obscured by the common assumption that they can be captured in one unified thesis, or a small number of closely related theses, and by the widespread neglect to take Leibniz’s division of reality into several ontological levels into consideration. I disentangle ten Leibnizian theses about relations, extrinsic denominations, and their relation to intrinsic denominations. Some of these theses express a kind of dependence of extrinsic denominations on intrinsic ones, and some of them can even be counted as articulations of a form of reductionism. But, overall, the general tenor of Leibniz’s position on extrinsic denominations remains non-reductionist.
“Leibniz on motion—Reply to Slowik,” The Leibniz Review XIX (2009): 139–147. Download!
This essay is a reply to Edward Slowik's critical discussion of my paper "Leibniz on Motion and the Equivalence of Hypotheses."
“Leibniz on motion and the equivalence of hypotheses,” The Leibniz Review XVIII (2008): 1–40. Download!
I argue that, contrary to popular belief, Leibniz is not hopelessly confused about motion. Leibniz is indeed both a relativist and an absolutist about motion, as suggested by the textual evidence, but, appearances to the contrary, this is not a problem; Leibniz’s infamous doctrine of the equivalence of hypotheses is well supported and well integrated in his physical theory; Leibniz’s assertion that the simplest hypothesis of several equivalent hypotheses can be held to be true can be explicated in such a way that it makes good sense; the mere Galilean invariance of Leibniz’s conservation law does not compromise his relativism about motion; and Leibniz has a straightforward response to Newton’s challenge that the observable effects of the inertial forces of rotational motions allow us to empirically distinguish absolute from relative motions.
“The modal strength of Leibniz’s principle of the identity of indiscernibles,” in Dan Garber and Steven Nadler (editors), Oxford Studies in Early Modern Philosophy, Oxford/New York City: Oxford University Press (2008), 191–225. Download!
It is surprisingly difficult to determine what modal strength Leibniz wants to ascribe to his principle of the identity of indiscernibles (PII). I consider this question by examining (i) some direct textual evidence, (ii) Leibniz's main arguments for PII, (iii) Leibniz's presumable response to a prominent contemporary defense of the necessity of PII against Max Black style counterexamples, and (iv) Leibniz's views about the possibility of primitive haecceities. I conclude that Leibniz probably takes PII to be necessary.
“Kant’s critique of the Leibnizian philosophy: contra the Leibnizians, but pro Leibniz,” in Dan Garber and Béatrice Longuenesse (editors), Kant and the Early Moderns, Princeton: Princeton University Press (2008), 41–63 (and 214–223 notes). Download!
I argue that the popular story that portrays Kant's philosophical development as a gradual emancipation from his Leibniz-Wolffian roots that culminates in a total rejection of Leibniz's philosophy by 1781 is not accurate. Kant's many objections against the Leibnizian philosophy in the critical period are not directed against Leibniz himself but against the Leibniz-Wolffians. Kant considers Leibniz's philosophy to be very close to his own, calling the Critique of Pure Reason the "true apology" of Leibniz. I submit that this assessment is correct, and illustrate the closeness of Kant and Leibniz by identifying several important similarities in their theories of space.
“Must Empiricism Be a Stance, and Could it Be One? How to Be an Empiricist and a Philosopher at the Same Time,” in Bradley Monton (editor), Images of Empiricism: Essays on Science and Stances, with a Reply from Bas van Fraassen, Oxford/New York City: Oxford University Press (2007), 271–318. Download!
In his recent book, The Empirical Stance, Bas van Fraassen raises the question of what a philosophical position can or should be. He mainly examines this question with respect to empiricism but his discussion makes it clear that he takes his proposed answer to be generalizable: not only empiricism but philosophical positions in general should be understood as stances rather than dogmata. The first part of this essay is devoted to an examination of van Fraassen’s critique of ‘naïve’ or dogmatic empiricism, which represents an integral part of his argument for stance empiricism. I argue that not all versions of naïve empiricism run into the problems identified by him. In the second part of the paper, I go on to show that, contrary to what van Fraassen claims, the stance empiricist is in no better position to provide a radical critique of metaphysics than the naïve empiricist. The third part concerns van Fraassen’s general proposal. I examine the question of whether a philosophical position can possibly consist in a stance and suggest that the answer is no. With respect to empiricism, this has the implication that if one wants to be a philosopher and an empiricist at the same time one needs to subscribe to a form of naïve empiricism. Moreover, as a philosopher-empiricist one should want, or at least allow, some form of metaphysical theorizing to be part of philosophy after all.