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.

In a text written during his stay in Paris, Leibniz, to deny ontological reality to relations, employs an argument well known to the medieval thinkers and which later would be revived by Francis H. Bradley. If one assumes that relations are real and that a relation links any property to a subject – so runs the argument – then one falls prey to an infinite regress. Leibniz seems to be well aware of the consequences that this argument has for his own metaphysical views, where the relation of inherence (‘inesse’) plays such a central role. Thus, he attempts first to interpret the relation of inherence as something ‘metaphoric’, originating from our ‘spatial way’ of looking at the surrounding world; and then he tries to reduce it to the part-whole relation which clearly he considers weaker, from the ontological point of view, than that of ‘being in’.

In this article, I propose a conjecture concerning the transmission of Spinoza’s Korte Verhandeling (KV) in the 1670s involving Leibniz. On the basis of a report about Spinoza’s philosophy written down by Leibniz after some conversations with Tschirnhaus in early 1676, I suggest that Tschirnhaus may have had in his possession a manuscript copy of KV and that his account of Spinoza’s doctrine to Leibniz was colored by this text. I support the hypothesis partly by means of external evidence, but mainly through a comparative analysis of Leibniz’s report and the doctrine contained in KV, showing that the report in important respects corresponds better to this text than to Ethics. I finally point to the importance that this hypothesis, if true, would have for our knowledge of Tschirnhaus’ role in the first diffusion of Spinoza’s philosophy outside Holland and for our understanding Leibniz’s reception of Spinoza in the mid-1670s.

My aim in this paper is to underscore the novelty of Leibniz’s teleology from a historical perspective. I believe this perspective helps deliver a better understanding of the finer details of Leibniz’s employment of final causes. I argue in this paper that Leibniz was taking a stance on three central teleological issues that derive from Aristotle, issues that seem to have occupied nearly every advocate of final causes from Aristotle to Leibniz. I discuss the three Aristotelian issues, and how major thinkers treated them in the medieval period. I argue that Leibniz rejected all of the mainstream Aristotelian teleological views on these issues. I conclude that Leibniz broke with longstanding threads of teleological thinking in ways that were often extreme.

Leibniz holds that nothing in nature strictly corresponds to any geometric curve or surface.Yet on Leibniz’s view, physicists are usually able to ignore any such lack of correspondence and to investigate nature using geometric representations. The primary goal of this essay is to elucidate Leibniz’s explanation of how physicists are able to investigate nature geometrically, focussing on two of his claims: (i) there can be things innature which approximate geometric objects to within any given margin of error; (ii) the truths of geometry state laws by which the phenomena of nature are governed. A corollary of Leibniz’s explanation is that physical bodies do have boundaries with which geometric surfaces can be compared to very high levels of precision. I argue that the existence of these physical boundaries is mind-independent to such an extent as to pose a significant challenge to idealist interpretations of Leibniz.