Paul Lodge

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.

Unlike most of the other great philosophers Leibniz never wrote a magnum opus, so his philosophical correspondence is essential for an understanding of his views. This collection of essays by pre-eminent figures in the field of Leibniz scholarship is a most thorough account of Leibniz's philosophical correspondencee. It both illuminates Leibniz's philosophical views and pays due attention to the dialectical context in which the relevant passages from the letters occur. The result is a book of enormous value to all serious students of early-modern philosophy and the history of ideas.

In a recent paper, Dennis Plaisted examines an important argument that Leibniz gives for the existence of primitive concepts. After sketching a natural reading of this argument, Plaisted observes that the argument appears to imply something clearly inconsistent with Leibniz’s other views. To save Leibniz from contradiction, Plaisted offers a revision. However, his account faces a number of serious difficulties and therefore does not successfully eliminate the inconsistency. We explain these difficulties and defend a more plausible alternative. In the process, we call attention to the neglected topic of Leibniz’s views on the nature of conceiving, and reveal his commitment to the somewhat surprising thesis that one can conceive something through a concept even if one has no conscious grasp of that concept.