Paul Lodge

Thanks to the efforts of Paul Schrecker and John W. Nason some half century ago, the University of Pennsylvania is home to microfilm reproductions of over one hundred thousand hand-written pages drawn from the collection of Leibniz’s papers presently housed in the Niedersächsische Landesbibliothek, Hannover. The microfilms are to be found on the mezzanine floor of the reference section in the Van Pelt Library and are readily accessible to visitors. Xerox copies may be made, although the Van Pelt Library stresses that the microfilms remain the property of the Niedersächsische Landesbibliothek, and that permission to copy must be obtained from Hannover beforehand.

Locke and Leibniz on Substance gathers together papers by an international group of academic experts, examining the metaphysical concept of substance in the writings of these two towering philosophers of the early modern period. Each of these newly-commissioned essays considers important interpretative issues concerning the role that the notion of substance plays in the work of Locke and Leibniz, and its intersection with other key issues, such as personal identity. Contributors also consider the relationship between the two philosophers and contemporaries such as Descartes and Hume

It has become something of a received view among contemporary scholars that Leibniz first adopted the pre-established harmony around the time of the Discourse on Metaphysics and Correspondence with Arnauld, i.e., 1686-87. However, in their recent contribution to the Cambridge Companion to Leibniz, Christia Mercer and Robert Sleigh Jr. have challenged this orthodoxy by claiming that Leibniz was committed to the doctrine, in all but name, by April 1676. In the present paper, I argue that the evidence that Mercer and Sleigh present to support their somewhat radical thesis is problematic in a number of respects. But rather than embracing the ‘received view’, I present further evidence in favor of the view that Leibniz had in fact adopted the pre-established harmony by 1679.

This paper illuminates Leibniz’s conception of faith and its relationship to reason. Given Leibniz’s commitment to natural religion, we might expect his view of faith to be deflationary. We show, however, that Leibniz’s conception of faith involves a significant non-rational element. We approach the issue by considering the way in which Leibniz positions himself between the views of two of his contemporaries, Bayle and Locke. Unlike Bayle, but like Locke, Leibniz argues that reason and faith are in conformity. Nevertheless, in contrast to the account that he finds in Locke’s Essay, Leibniz does not reduce faith to a species of reasonable belief. Instead, he insists that, while faith must be grounded in reason, true or divine faith also requires a supernatural infusion of grace.

Between 1698 and 1706 Leibniz was engaged in one of his most interesting correspondences, with the Dutch philosopher and physicist Burcher de Volder. The two men were concerned primarily with the question of how the motion of bodies can be explained without appeal to the direct intervention of God. Leibniz presented a naturalistic account of motion to De Volder, but failed to convince him of its adequacy. I shall examine one reason for this failure - the disagreement that arose over the issue of whether there is a substance whose nature is constituted by extension.

Section 17 of Leibniz’s Monadology contains a famous argument in which considerations of what it would be like to enter a machine that was as large as a mill are offered as reasons to reject materialism about the mental. In this paper, I provide a critical discussion of Leibniz’s mill argument, but, unlike most treatments, my discussion will focus on texts other than the Monadology in which considerations of the mill also appear. I provide a survey of three previous interpretations of the argument and a partial defence of one of them, namely the one that Marc Bobro and I offered in Stepping Back Insider Leibniz's Mill (The Monist, 1998). However, I also argue that a fourth interpretation is necessary to account for the appearances of Leibniz’s mill in at least some of his writings.

According to Robert Sleigh Jr., “The opening remarks of DM.18 make it clear that Leibniz took the results of DM.17 as either establishing, or at least going a long way toward establishing, that force is not identifiable with any mode characterizable terms of size, shape, and motion.” Sleigh finds this puzzling and suggests that other commentators have generally been insufficiently perplexed by the bearing that the DM.17 has on the metaphysical issue. He notes that §17 of the Discourse is a presentation of “the argument of the Brevis demonstratio to the effect that Descartes erred in measuring force in terms of mass and velocity, rather than in terms of mass and the square of velocity,” and observes that, given this, it is initially plausible to think that Leibniz ought to have concluded the very opposite, for “if force were measurable in terms of mass and the square of velocity—then force would be characterizable in terms of size and motion.”

In discussion of Leibniz’s philosophical methodology Donald Rutherford defends the view that Leibniz regarded metaphysics as an a priori demonstrative science. In the course of this discussion Rutherford isolates and tries to deflect a significant challenge for his view, namely the observation that in many of his mature writings on metaphysics Leibniz appears to defend his views by means of a posteriori arguments. I present some prima facie difficulties with Rutherford’s position and then offer an alternative account of how Leibniz thought he needed to establish metaphysical claims. My suggestion is that the challenge that Rutherford poses may be best answered by attending to the fact that Leibniz recognized a kind of metaphysical enquiry, ‘real metaphysics’, that is essentially a posteriori, in virtue of the fact that it is concerned not just with possible kinds of beings, but with the kinds of beings that God actually created.

Seine Kritik an Descartes' Auffassung vom Körper gründet Leibniz bekanntlich auf Erörterungen zur Teilbarkeit und Ausdehnung. Obgleich jene Argumentation im Fokus einer Auseinandersetzung mit Leibniz' Metaphysik angesiedelt werden muss, ist sie bisher nicht recht verstanden worden. Mein Anliegen hier ist im Kern, Leibniz' Gedankengang zu explizieren und dessen Stichhaltigkeit auszuleuchten. Das Argument, um das es geht, ist wohl am ehesten aus der Darlegung in Leibniz' Korrespondenz mit Antoine Arnauld bekannt, findet sich jedoch zudem im späteren Briefwechsel mit De Volder. Neben Parallelen gibt es zwischen den Verfahrensweisen, die Leibniz in den zwei Korrespondenzen jeweils favorisiert, gleichwohl derart signifikante Differenzen, dass es nicht unbegründet scheint, ihm auch zwei Argumentationslinien zuzuschreiben -die Unterschiede dieser Linien werde ich im Folgenden auch hinsichtlich ihres Entstehungszusammenhangs beleuchten und einen Ausblick auf weitere Forschungserfordernisse wagen