Martin Lin

The seventeenth century was nearly unanimous in regarding causation as a necessary connection. If the cause exists or occurs, then, necessarily, the effect exists or occurs. The source of this unanimity has puzzled scholars. That causation is a necessary connection was not commonly held by medieval philosophers nor is it a commonly held opinion today. What accounts for this surprising seventeenth century consensus? In this chapter, I examine both Spinoza and Leibniz on efficient causation and argue that both regard efficient causation as a form of necessitation. But I conclude that their explicit reasons for doing so are not shared. Thus, their explicit reasoning sheds little light on the puzzle.

abstract: Leibniz holds that there are no two perfectly similar things, a doctrine he calls the Principle of the Identity of Indiscernibles (the PII). What is his attitude toward its modal status? Most commentators hold that the principle is best understood as a necessary truth because it is allegedly entailed by doctrines such as the conceptual containment theory of truth, the Principle of Sufficient Reason (the PSR), and the denial of purely extrinsic denominations, which are arguably regarded by Leibniz as necessary truths. In this paper, I argue against this consensus and show that (1) neither the conceptual containment theory of truth, nor the PSR, nor the denial of purely extrinsic denominations give Leibniz a good reason to hold that the PII is necessary; (2) Leibniz says that the PII is contingent in the correspondence with Clarke and not for dialectical reasons; and (3) the argument that Leibniz gives for the PII in §21 of his Fifth Letter to Clarke has been misunderstood; properly interpreted, it gives Leibniz a cogent argument rooted in some of his most important doctrines for the conclusion that the PII is a contingent truth.

In Spinoza’s metaphysics, we encounter many puzzling doctrines that appear to entangle metaphysical notions with cognitive, logical, and epistemic ones. According to him, a substance is that which can be conceived through itself and a mode is that which is conceived through another. Thus, metaphysical notions, substance and mode, are defined through a notion that is either cognitive or logical, being conceived through. He defines an attribute as that which an intellect perceives as constituting the essence of a substance. Intellectual perception, something cognitive, is used to define an attribute, something metaphysical. And he claims that if something exists there is a reason why it exists and if something doesn’t exist there is also a reason why it doesn’t. Thus, a reason, something cognitive or epistemic, is necessary for existence or nonexistence. What are we to make of the intimate connections that Spinoza sees between metaphysical, cognitive, logical, and epistemic notions? Between being and reason? In this book, I argue for what might be called a realist interpretation: although Spinoza is confident that the order of being mirrors the order of reason, he believes that they are two orders, not one. There is inherence over and above conceptual dependence; there is causation in addition to causal explanation; the world has a nature that we can grasp and that our way of grasping it does not interpose an impenetrable conceptual veil between it and us.

It is often thought that, although Spinoza develops a bold and distinctive conception of God (the unique substance, or Natura Naturans, in which all else inheres and which possesses infinitely many attributes, including extension), the arguments that he offers which purport to prove God’s existence contribute nothing new to natural theology. Rather, he is seen as just another participant in the seventeenth century revival of the ontological argument initiated by Descartes and taken up by Malebranche and Leibniz among others. That this is the case is both puzzling and unfortunate. It is puzzling because although Spinoza does offer an ontological proof for the existence of God, he also offers three other non‐ontological proofs. It is unfortunate because these other non‐ontological proofs are both more convincing and more interesting than his ontological proof. In this paper, I offer reconstructions and assessments of all of Spinoza’s arguments and argue that Spinoza’s metaphysical rationalism and his commitment to something like a Principle of Sufficient Reason are the driving force behind Spinoza’s non‐ontological arguments.

For Spinoza, human desire manifests the striving for self-preservation exhibited by all natural things. In the dissertation, I argue that Spinoza's theory of desire provides the basis for his theory of human nature, its place in the larger natural order, and its ethical possibilities. Human nature presented a particularly pressing problem for the seventeenth century on account of the ways in which modern science had reconceived the natural world. No longer were appeals to hylomorphism, substance pluralism, on final causes countenanced by progressive modern philosophers, and instead a post-Copernican and mechanical philosophy held sway. These developments were primarily worked out in the domains of astronomy, chemistry, and mechanics, but had not been adequately extended to answer the question of the place on the human being in the natural world. Spinoza's theory of desire provides an answer to this question. I begin by examining Spinoza's metaphysical arguments in support of the conatus doctrine in general, and present a new interpretation of these arguments according to which they are much stronger and more interesting than have been previously supposed. I then show how Spinoza uses this general metaphysical principle to account for human nature more specifically, focusing especially on the human body, cognitive psychology, and moral psychology.

The editors of this volume, in their introduction, take Jonathan Bennett’s A Study of Spinoza’s Ethics as the exemplar for the eleven essays collected here, hailing Bennett’s book as setting “new standards for philosophical research on Spinoza”. Bennett’s work is indeed a worthy model. Aside from its more generic virtues, such as learnedness and conceptual rigor, perhaps what is most distinctive about Bennett’s treatment of Spinoza is his method, which he calls the “collegial approach.” This method proceeds by studying “the texts in the spirit of a colleague, an antagonist, a student, a teacher—aiming to learn as much philosophy as one can from studying them.” Bennett has, employing this approach, produced a large number of useful works on early modern philosophers, and his efforts concerning Spinoza are among the best of them. But does Bennett’s example provide any unity for this collection? A number of these essays, Della Rocca’s and Manning’s, for example, indeed take what could be fairly described as a collegial approach to the study of Spinoza. Still others, however, such as Kulstad’s, place more emphasis on historical scholarship than the collegial approach prescribes. This matters, however, very little. Exemplary as Bennett’s work is, the study of the history of early modern philosophy has, in recent years, benefited from the work of scholars using a wide variety of methods. I think it fair to say that the essays collected in this volume, not at all to their detriment, reflect this diversity.

: Perhaps the central problem which preoccupies Spinoza as a moral philosopher is the conflict between reason and passion. He belongs to a long tradition that sees the key to happiness and virtue as mastery and control by reason over the passions. This mastery, however, is hard won, as the passions often overwhelm its power and subvert its rule. When reason succumbs to passion, we act against our better judgment. Such action is often termed 'akratic'. Many commentators have complained that the psychological principles that Spinoza appeals to in his account of akrasia are mere ad hoc modifications to his philosophical psychology. I show, on the contrary, that these principles follow from some of the most important and interesting aspects of Spinoza's philosophy of mind

Metaphysical rationalism, the doctrine which affirms the Principle of Sufficient Reason (the PSR), is out of favor today. The best argument against it is that it appears to lead to necessitarianism, the claim that all truths are necessarily true. Whatever the intuitive appeal of the PSR, the intuitive appeal of the claim that things could have been otherwise is greater. This problem did not go unnoticed by the great metaphysical rationalists Spinoza and Leibniz. Spinoza’s response was to embrace necessitarianism. Leibniz’s response was to argue that, despite appearances, rationalism does not lead to necessitarianism. This paper examines the debate between these two rationalists and concludes that Leibniz has persuasive grounds for his opinion. This has significant implications both for the plausibility of the PSR and for our understanding of modality.