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. -/- PS from the author: I maintain a list of errata plus corrections on my website (which can easily be found by googling my name). If you discover additional errors, typos, or unfortunate formulations, I would be grateful to hear from you. -/- . (shrink)

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. -/- . (shrink)

Contrary to popular belief, I argue that 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 within Leibniz’s 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 Leibniz’s relativism about motion; and Leibniz has a straightforward response to Newton’s challenge that the observable effects of the inertial forces of rotational motions empirically distinguish absolute from relative motions. (shrink)

In his recent book, The Empirical Stance, Bas van Fraassen forcefully raises the question of what a philosophical position can or should be. He mainly discusses this question with regard 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. It will be argued that, contrary to van Fraassen’s view, not all versions of naïve empiricism run into the problems identified by him. In the second part of the paper the case will be made that, contrary to van Fraassen’s thesis, the stance empiricist is in at least as bad a position as the naïve empiricist with regard to the task of providing a radical critique of metaphysics, which van Fraassen takes to be an essential task that any empiricist should be able to accomplish. The third part of this essay concerns van Fraassen’s general proposal, and examines the question whether a philosophical position can possibly consist in a stance. It will be suggested that this is not the case. With regard 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. Furthermore, it will be proposed that as a philosopher-empiricist one should want, or, at least, allow some form of metaphysical theorizing to be part of the philosophical enterprise after all. (shrink)

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. (shrink)

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. (shrink)

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. (shrink)

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.

Review of Kant’s Moral Metaphysics, edited by Benjamin Lipscomb and James Krueger, de Gruyter, 2010.

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. (shrink)

Response to critical comments by Edward Slowik on my article 'Leibniz on Motion and the Equivalence of Hypotheses' in The Leibniz Review 18 (2008).

It is argued that the popular story that portrays Kant’s philosophical development as a gradual emancipation from his Leibniz-Wolffian roots that culminated in a total rejection of the Leibnizian 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. It is claimed (...) that this assessment is correct; the correctness is demonstrated with respect to Kant’s and Leibniz’s theories of space. (shrink)

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. (shrink)

In Immanuel Kant's pre-critical writings as well as in his main critical work, the Critique of Pure Reason, one finds a whole battery of fierce attacks on core doctrines of Leibnizian philosophy, e.g., the monadology, the principle of the identity of indiscernibles, the principle of sufficient reason, the doctrine of the pre-established harmony, or the relationalist theory of space and time. It is tempting to read Kant's philosophical development as a gradual emancipation from his Leibnizian upbringing, culminating in a thorough (...) rejection of Leibnizian philosophy as a paradigm case of the kind of dogmatic metaphysics that Kant wants to overcome with his critical philosophy. But in addition to the familiar texts in which Kant attacks the Leibnizians there are several curious, less well-discussed passages in which Kant speaks in highly approving terms of Leibniz. In these passages Kant self-avowedly defends Leibniz against his Leibniz-Wolffian followers who, according to Kant, have seriously misunderstood Leibniz's original position. Kant maintains that a correct reading of Leibniz reveals that his own and Leibniz's views are in fact very close, and that with regard to many issues that are central to transcendental idealism Leibniz had already tried to say what Kant then made explicit in his critical work. The project of this essay is to lay the foundation for the examination of an unorthodox reading of the relation between Leibnizian metaphysics and Kantian transcendental idealism, according to which Kant's critical philosophy can correctly be described as the "true apology of Leibniz", as Kant claims, while Kant's sharply critical objections in the pre-critical works and in the Critique of Pure Reason for the most part don't apply to Leibniz's original theory but to Leibniz-Wolffian school-philosophy. The present essay provides the necessary groundwork for the examination of this unorthodox reading by showing that, and to what extent, these Kantian objections do not apply to Leibniz himself, and by arguing that Kant's reading of certain central Leibnizian doctrines in which Leibnizian metaphysics is represented as a forerunner of transcendental idealism is indeed defensible. (shrink)