The Principle of Sufficient Reason —the principle that everything has a reason—plays a central role in Leibniz’s philosophical system. It is rather difficult, however, to determine what Leibniz’s attitude towards the modal status of the PSR is. The prevailing view is that Leibniz takes the PSR to be true necessarily. This paper develops a novel interpretation and argues that Leibniz’s PSR is a contingent principle. It also discusses whether a merely contingent PSR can do the metaphysical (...) heavy lifting that Leibniz aims for. The paper shows that, despite appearance to the contrary, this is possible. In a nutshell, the argument is that the only possible PSR violation Leibniz allows for is God’s creation of a suboptimal world; there is no Leibnizian possible world, though, which intrinsically violates the PSR. Despite its contingency, then, Leibniz’s PSR is modally robust enough to serve as a foundational principle of his metaphysics. (shrink)

This essay deals with a Leibnizian version of the argument from the contingent existence of the world to the necessary existence of God, especially with the statements of the argument presented by Father Copleston in his famous B.B.C. debate with Bertrand Russell and, more recently, by Richard Taylor, in his Metaphysics. The essay is divided into two parts. In the first part, I am chiefly concerned with showing how the principle of sufficient reason, together with the claim that (...) something contingent exists, will allow us to conclude, without any appeal to the impossibility of an infinite series of contingent causes, that there exists a necessary being distinct from the world of contingent beings. In the second part of the essay, I try to show that, in a form strong enough to support the argument, the principle of sufficient reason has the implication—undesirable to many, but not all theists— that nothing could be logically contingent. (shrink)

This article aims to reconstruct the way by which Leibniz presents in some of his texts an a posteriori proof of God’s existence. To this end, we intend to demonstrate the centrality of the Principle of Sufficient Reason applied to the contingency of the passage to the existence of a given world. Once demonstrated the existence of God by these ways, and still taking into account the Principle of Sufficient Reason - now applied to the existence (...) of this world in particular -, we will discuss the theory of possible worlds and Leibniz’s thesis according to which the Actual World is the most perfect possible. (shrink)

Leibniz has long faced a challenge about the coherence of the distinction between necessary and contingent truths in his philosophy. In this paper, I propose and examine a new way to save genuine contingency within a Leibnizian framework. I conclude that it succeeds in formally solving the problem, but at unbearable cost. I present Leibniz’s challenge by considering God’s choice of the best possible world (Sect. 2). God necessarily exists and necessarily chooses to actualise the best possible world. The actual (...) world therefore could not be different, for if it were different it would be a distinct and inferior world and hence would not be created. In Sect. 3 I defend Leibniz from this challenge. I argue that while it is necessary for God to choose to create the best possible world, it is not necessary for any world to be the best possible. This is because the criterion for judging perfection can itself be contingent. Different criteria will judge different worlds as the best. Thus it is necessary for God to create the best, but not necessary which is the best. Distinguishing between possible worlds in Leibniz’s sense and in the modern sense allows a fuller exposition of this position. There are worries that can arise with the claim that the criterion of perfection is contingent. I consider two of the most pressing (Sect. 4). The first argues that the criterion is in God’s understanding and hence is necessary; the second alleges that a contingent criterion of perfection violates Leibniz’s cherished Principle of Sufficient Reason. These worries are well-grounded, and examining them reveals a deep incompatibility between this solution and Leibniz’s metaphysical views. I conclude that there is a real solution available, but that it is unacceptable to Leibniz or a Leibnizian. The search for a genuine solution that is genuinely Leibnizian goes on. (shrink)

I examine several alleged grounds of the principle of sufficient reason in Leibniz’s philosophy. These include the nature of a requisite and a sufficient condition, the nature of truth, and the nature of harmony. I argue that Leibniz does not ground the PSR in any of these ways. Instead, he is committed to a value-based grounds of the PSR: God creates the best possible world, and the fact that the PSR obtains in this world contributes to it (...) being the best. I conclude by considering some objections to this way of grounding the PSR. (shrink)

The aim of this paper is to defend the ontological Principle of Sufficient Reason (PSR-O). I analyse various versions of this principle and various ways of justifying it. Then I attempt to challenge some counterexamples allegedly refuting a universal application of the PSR-O. There are standard and non-standard versions of the PSR-O. The PSR-Ostand can only be valid if there are no chains of contingent reasons and outcomes with first modules, i.e. all chains are actually infinite. However, (...) there are serious arguments against this possibility. The necessary condition of the PSR-Onon-stand is the existence of a necessary substance: that substance would be a direct reason of certain contingent states of affairs obtaining in its domain, and those states of affairs would then be indirect reasons for all other contingent states of affairs and things. There are two advantages of the PSR-Onon-stand: a nomological unity of the world and explanatory simplicity. (shrink)

Leibniz’s famous Principle of the Identity of Indiscernibles (PII) states that no two things are exactly alike. The PII is commonly thought to be metaphysically necessary for Leibniz: the coexistence of two indiscernibles is metaphysically impossible. This paper argues, against the standard interpretation, that Leibniz’s PII is metaphysically contingent. In other words, while the coexistence of indiscernibles would not imply a contradiction, the PII is true in the actual world because the Principle of Sufficient Reason rules out (...) violations of the PII. God could have created indiscernibles but he did not because he is wise and does nothing without a sufficient reason. Because it is plausible that all Leibnizian possible worlds are unified by a wise plan, this means that the PII is true in all possible worlds. God could create indiscernibles, but the resulting creation would not be a world. To argue for this conclusion, the paper carefully examines Leibniz’s mature account of metaphysical contingency. It shows that for Leibniz, only states of affairs that imply logical contradictions are metaphysically impossible. Next, it argues that the coexistence of indiscernibles would not imply a logical contradiction; it would merely imply what Leibniz calls a “moral absurdity,” that is, a violation of the Principle of Sufficient Reason. This means that the PII is true contingently and—since God can do whatever is metaphysically possible—that God can create two things that are exactly alike. (shrink)

The Principle of Sufficient Reason says that all contingent facts must have explanation. In this 2006 volume, which was the first on the topic in the English language in nearly half a century, Alexander Pruss examines the substantive philosophical issues raised by the Principle Reason. Discussing various forms of the PSR and selected historical episodes, from Parmenides, Leibnez, and Hume, Pruss defends the claim that every true contingent proposition must have an explanation against major objections, including Hume's (...) imaginability argument and Peter van Inwagen's argument that the PSR entails modal fatalism. Pruss also provides a number of positive arguments for the PSR, based on considerations as different as the metaphysics of existence, counterfactuals and modality, negative explanations, and the everyday applicability of the PSR. Moreover, Pruss shows how the PSR would advance the discussion in a number of disparate fields, including meta-ethics and the philosophy of mathematics. (shrink)

According to the Principle of Sufficient Reason (‘PSR’), every fact has an explanation for why it obtains. If the PSR is true, there must be a sufficient reason for why God chose to create our world. But a sufficient reason for God’s choice plausibly necessitates that choice. It thus seems that God could not have done otherwise, and that our world exists necessarily. We therefore appear forced to pick between the PSR, and the contingency of creation (...) and divine choice. I show that a third option remains open, and thus that it is possible to preserve the contingency of creation and divine choice even while endorsing the PSR. My solution depends on the coherence of a restricted modal realism. On this modal realism, there is more than one possible morally optimal created world, and for each such world there is an existing possibility in which God creates that world. (shrink)

Leibniz's principle of sufficient reason is the claim that everything has a sufficient reason. But is Leibniz committed to the necessity or to the contingency of his great principle? I argue that Leibniz is committed to its contingency, given that he allows for the absolute possibility of entities that he claims violate the PSR. These are all cases of qualitatively indiscernible entities, such as indiscernible atoms, vacua, and bodies. However, Leibniz's commitment to the contingency of the (...) PSR seems to stand in tension with his inference of the PSR from his theory of truth. I argue that this apparent tension can be resolved satisfactorily. When it comes to his modal views on the PSR, Leibniz's position is entirely consistent. (shrink)

According to Principles of Sufficient Reason, every truth (in some relevant group) has an explanation. One of the most popular defenses of Principles of Sufficient Reason has been the presupposition of reason defense, which takes endorsement of the defended PSR to play a crucial role in our theory selection. According to recent presentations of this defense, our method of theory selection often depends on the assumption that, if a given proposition is true, then it has an explanation, and (...) this will only be justified if we think this holds for all propositions in the relevant group. I argue that this argument fails even when restricted to contingent propositions, and even if we grant that there is no non-arbitrary way to divide true propositions that have explanations from those that lack them. Further, we can give an alternate explanation of what justifies our selecting theories on the basis of explanatory features: the crucial role is not played by an endorsement of a PSR, but rather by our belief that, prima facie, we should prefer theories that exemplify explanatory power to greater degrees than their rivals. This guides our theory selection in a manner similar to ontological parsimony and theoretical simplicity. Unlike a PSR, our belief about explanatory power gives us a prima facie guiding principle, which provides justification in the cases where we think we have it, and not in the cases where we think we don't. (shrink)

The aim of this paper is to render a detailed analysis of the correspondence with Clarke in order to shed some light in the relationship between the Principle of Identity of Indiscernibles and the Principle of Sufficient Reason. Most of the secondary literature takes for granted that Leibniz derives the Principle of Identity of Indiscernible from the Principle of Sufficient Reason in at least some parts of the correspondence. This would render the Principle (...) of Identity of Indiscernibles a merely contingent truth and not a necessary principle. I will argue that this interpretation is misleading, and that Leibniz never abandoned the idea that the Principle of Identity of Indiscernibles is a necessary truth. Although he is continuously using the Principle of Sufficient Reason in his argumentation, he keeps in parallel a strong argumentation that entails the necessity of the Principle of Identity of Indiscernibles. To achieve this goal, it will be necessary to point out first some contextual facts that may determine a correct understanding of the correspondence. It will be also necessary to frame the discussion about the principles into the broader debate on the possibility of Newtonian space. Finally, it will be shown that the mentioned hypothesis is supported by textual evidence throughout the entire correspondence. (shrink)

This paper focuses on Leibniz’s conception of modality and its application to the issue of natural laws. The core of Leibniz’s investigation of the modality of natural laws lays in the distinction between necessary, geometrical laws on the one hand, and contingent, physical laws of nature on the other. For Leibniz, the contingency of physical laws entailed the assumption of the existence of an additional form of causality beyond mechanical or efficient ones. While geometrical truths, being necessary, do not require (...) the use of the principle of sufficient reason, physical laws are not strictly determined by geometry and therefore are logically distinct from geometrical laws. As a consequence, the set of laws that regulate the physical laws could have been created otherwise by God. However, in addition to this, the contingency of natural laws does not consist only in the fact that God has chosen them over other possible ones. On the contrary, Leibniz understood the status of natural laws as arising from the action internal to physical substances. Hence the actuality of physical laws results from a causal power that is inherent to substances rather than being the mere consequence of the way God arranged the relations between physical objects. Focusing on three instances of Leibniz’s treatment of contingency in physics, this paper argues that, in order to account for the contingency of physical laws, Leibniz maintained that final causes, in addition to efficient and mechanical ones, must operate in physical processes and operations. (shrink)

Argues that that all necessity is consequent, and that reason and God are contingent, albeit eternal, necessitiesFocusing on the central striking claim that there is something rather than nothing - that all necessity is consequent - Tritten engages with a wide range of ancient as well as contemporary philosophers including Quentin Meillassoux, Richard Kearney, Friedrich Schelling, Émile Boutroux and Markus Gabriel. He examines the ramifications of this truth arguing that even reason and God, while necessary according to essence, are utterly (...) contingent with respect to existence.Key FeaturesShows how all necessary truths are products of an epistemic framework that is itself historically contingentExplains the nature of contingency as something that stems from the facticity of being itself Explains the emergence and ontological status of reason, particularly the principle of sufficient reasonArgues for the contingency of God's existence while maintaining the necessity of his essenceProvides an alternative to Quentin Meillassoux's thesis for the necessity of contingency". (shrink)

In The Metaphysics of Creation and The Metaphysics of Theism, Norman Kretzmann defends an argument for God's existence which he claims to find in Aquinas. I assess this argument's key premise, a principle of sufficient reason, that: ‘PSR2: Every existing thing has a reason for its existence either in the necessity of its own nature or in the causal efficacy of some other beings’. PSR2 requires God's nature to explain His existence. Kretzmann does not tell us how this (...) explanation is supposed to go. I examine such ways as I can envision that God's own nature might explain His existence. None pan out. I argue contra Kretzmann that if God is simple, as Aquinas understood this, His nature does not explain His existence, and while His existence is in itself per se notum (‘self-evident’) this does not entail that it has an explanation. If this is correct, we ought not to read Aquinas as committed to PSR2. Further, if I'm right that it's impossible for ‘the necessity of a thing's nature’ to explain its existence, PSR2 is true only if every existing thing has a reason for its existence in the causal efficacy of some other beings. So, if I'm right, theists ought to steer clear of PSR2, at least read in terms of genuine explanation. I finally offer a weaker reading of ‘a reason for its existence’ which does not generate the problems of the stronger reading Kretzmann seems to have in mind. This too, though, turns out to have its problems. (shrink)

The consensus is that in his 1755 Nova Dilucidatio, Kant endorsed broadly Leibnizian compatibilism, then switched to a strongly incompatibilist position in the early 1760s. I argue for an alternative, incompatibilist reading of the Nova Dilucidatio. On this reading, actions are partly grounded in indeterministic acts of volition, and partly in prior conative or cognitive motivations. Actions resulting from volitions are determined by volitions, but volitions themselves are not fully determined. This move, which was standard in medieval treatments of free (...) choice, explains why Kant is so critical of Crusius’s version of libertarian freedom: Kant understands Crusius as making actions entirely random. In defense of this reading, I offer a new analysis of the version of the principle of sufficient reason that appears in the Nova Dilucidatio. This principle can be read as merely guaranteeing grounds for the existence of things or substances, rather than efficient causes for states and events. As such, the principle need not exclude libertarian freedom. Along the way, I seek to illuminate obscure aspects of Kant’s 1755 views on moral psychology, action theory, and the threat of theological determinism. (shrink)

According to a common reading, Spinoza and Leibniz stand on opposite ends of the modal spectrum. At one extreme lies ‘‘Spinoza the necessitarian,’’ for whom the actual world is the only possible world. At the other lies ‘‘Leibniz the anti-necessitarian,’’ for whom the actual world is but one possible world among an infinite array of other possible worlds; the actual world is privileged for existence only in virtue of a free decree of a benevolent God. In this paper, I challenge (...) both of these readings. Spinoza is no necessitarian and Leibniz is no anti-necessitarian – at least as these characterizations are usually understood. Rather, I contend, Spinoza and Leibniz are both anti-essentialists; they believe that the modality of objects can vary relative to how those objects are conceived. This shared commitment to anti-essentialism allows them to consistently affirm both necessitarianism and its denial, relative to different ways of conceiving the world. Their embrace of this modal theory, I further argue, is grounded in their similar views on metaphysical perfection, ontological plentitude, and the principle of sufficient reason. (shrink)

For Kant one of the goals of any critique of pure reason is to answer the question, how are a priori synthetic propositions possible? Because rationalists such as Eberhard and Wolff took the principle of sufficient reason (hereafter, the PSR) as the principle of all a priori synthetic judgments, understanding both the various formulations of this principle and arguments in favor of its use as an axiom in metaphysical reasoning provides an interesting back door to understanding (...) The Critique of Pure Reason. Despite his statements in the First Critique rejecting the PSR as a principle of judgment1, I argue that Kant was actually more sympathetic to the PSR than these passages alone would suggest. The Kant-Eberhard Controversy suggests that, even though Kant explicitly denies that the PSR can guide metaphysical reasoning, he actually presupposes its truth. I show that Kant’s position is tenable because, like the rationalists, Kant accepts the assumption that real essences exist and that they ground real possibility2; this leads him to accept the truth of all clear statements of the PSR. Unlike the rationalists, however, he does not accept the assumption that human understanding is isomorphic with real essences. As a result, Kant rejects only the use of the PSR to determine a priori the existence or properties of a thing. In this paper I hope to illuminate this position. I will begin with a survey of the various formulations of the PSR that have been put forward by Kant and his predecessors: Leibniz, Eberhard, and Wolff. Then I will examine Wolff and Eberhard’s arguments in favor of the PSR along with Kant’s criticisms of these arguments. Lastly, I will show why Kant rejected the very possibility of justifying this use of the PSR while presupposing its truth. (shrink)

The principle of sufficient reason asserts that anything that happens does so for a reason: no definite state of affairs can come into being unless there is a sufficient reason why that particular thing should happen. This principle is usually attributed to Leibniz, although the first recorded Western philosopher to use it was Anaximander of Miletus. The demand that nature be rational, in the sense that it be compatible with the principle of sufficient reason, (...) conflicts with a basic feature of contemporary orthodox physical theory, namely the notion that nature’s response to the probing action of an observer is determined by pure chance, and hence on the basis of absolutely no reason at all. This appeal to pure chance can be deemed to have no rational fundamental place in reason-based Western science. It is argued here, on the basis of other basic principles of quantum physics, that in a world that conforms to the principle of sufficient reason, the usual quantum statistical rules will naturally emerge at the pragmatic level, in cases where the reason behind nature’s choice of response is unknown, but that the usual statistics can become biased when the reason for the choice is empirically identifiable. It is explained here that if the statistical laws of quantum mechanics were to be biased in this way then the basically forward-in-time unfolding of empirical reality described by orthodox quantum mechanics would generate the appearances of backward-time-effects of the kind that have been reported in the scientific literature. (shrink)

The paper inspects Anderson’s central thesis that Kant’s dogmatic slumber was interrupted by Hume’s critique of metaphysics in his Enquiry concerning Human Understanding, namely, by his critique of the rationalist principle of sufficient reason, which lies at the heart of dogmatic proofs of God’s existence. I recreate the meaning of “Hume’s objection,” define the larger role the principle of sufficient reason plays in Kant’s philosophy, and evaluate the explanatory potential of Anderson’s interpretation in view of Kant’s (...) early and critical texts, as well as his other autobiographical statements. Although Anderson’s hypothesis seems well-founded and even explicates the hidden connection between the entire critical project and the refutation of Spinozism, I argue it is almost impossible to reconcile it with the current research in Kant’s Entwicklungsgeschichte. (shrink)

This paper locates a source of contingency for Leibniz in the fact that God can do otherwise, absolutely speaking. This interpretative line has been previously thought to be a dead-end because it appears inconsistent with Leibniz’s own conception of God, as the ens perfectissimum, or the most perfect being (Adams, 1994). This paper points out that the best argument on offer which seeks to demonstrate this inconsistency fails. The paper then argues that the supposition that God does otherwise implies for (...) Leibniz (at least) that God would not be praiseworthy, which is an absurd implication—or a violation of the principle of sufficient reason (PSR)—but that this is not, strictly speaking, an inconsistency—or a violation of the principle of contradiction (POC). While praiseworthiness is a perfection—and is compossible with God’s other perfections—and so God must instantiate it, this paper argues that, given the nature of praiseworthiness for Leibniz, it in fact makes sense to say that praiseworthiness is merely a contingent perfection of God. (shrink)

Leibniz denies Spinoza’s claim that all possible things actually exist. He also denies necessitarianism, Spinoza’s claim that all truths are necessary truths. Both denials seem plausible. What is surprising, however, is Leibniz’s view that the first claim entails the second, i.e., that the existence of all possible things implies necessitarianism. Why think this? Couldn’t it be that, as a matter of contingent fact, all possible things actually exist? There seems to be no incoherency in claiming both that all possible things (...) actually exist and that fewer things could have existed. In this paper, I explain why Leibniz thought that such a position is indeed inconsistent. My thesis is that the Principle of Sufficient Reason plays a decisive role in his reasoning. Leibniz claims that the non-existence of a thing requires a sufficient reason. He also holds that if all possible things can coexist, such a reason cannot be given. Together these claims rule out a scenario in which all possible things actually exist, but only contingently so. (shrink)

Toward the end of his classic treatise An Essay on Free Will, Peter van Inwagen offers a modal argument against the Principle of Sufficient Reason which he argues shows that the principle “collapses all modal distinctions.” In this paper, a critical flaw in this argument is shown to lie in van Inwagen’s beginning assumption that there is such a thing as the conjunction of all contingently true propositions. This is shown to follow from Cantor’s theorem and a (...) property of conjunction with respect to contingent propositions. Given the failure of this assumption, van Inwagen’s argument against the Principle of Sufficient Reason cannot succeed, at least not without the addition of some remarkable and previously unacknowledged qualifications. (shrink)

The objective of this paper is to show the unity of leibniz's philosophical system. the connection between his inesse-principle and the idea that our world is the best of all possible worlds is this: the individual 'concept' of alexander may be defined as containing his whole biography, but the existence of an 'individual' falling under this concept can be deduced a priori only on the basis of the principle of sufficient reason, the application of which takes into (...) account not only god's intellect but also his goodness. (shrink)

Kant wrote in the Only Possible Argument in Support of a Demonstration of the Existence of God, that existence is not a predicate of things. In this paper I argue that his thinking is based on the same view already in the New Elucidation, written in 1755. In this early text, Kant carefully distinguishes the grounds of existence from grounds of knowledge and argues that contingent existence always has an antecedently determining ground. I examine how Kant thinks that God contains (...) the extralogical grounds that are required for things not only to exist but also to undergo change and interact with other things. I also consider briefly how the New Elucidation could help us to understand Kant’s mature view on the grounds of existence. (shrink)

I conclude that it is more accurate to say that, rather than trying to make logic metaphysical, Leibniz tries, in the context of a theistic system, to make metaphysics logical. ;I begin with a study of the principle of identity of indiscernibles, and show how it is best thought of as a principle which follows from a metaphysical interpretation of the principle of sufficient reason. It has been traditional to interpret the principle of identity of (...) indiscernibles as primarily a merely logical principle, and thus as either trivially true, if Leibniz succeeds in proving it, or else false or contingently true. I argue that it is instead necessarily true in a non-trivial or metaphysical sense, because the principles on which it is based are themselves of this metaphysical character, contrary to what is often assumed. ;In the second chapter, I show how God's activity and a metaphysical interpretation of the principle of sufficient reason underlie Leibniz's account of space and time. ;In the third chapter, I discuss the principle of sufficient reason in detail, showing that it actually consists of three separate principles: the principle of grounds, that every true proposition has a proof a priori; the principle of reason, that God does nothing without a sufficient reason; and the principle of causation, that every event has a cause. That each of these is considered a principle of sufficient reason is explained by Leibniz's equivocal use of the term 'reason.' I show that, of the various versions of the principle of sufficient reason, only the principle of reasons provides an adequate foundation for Leibniz's principle of identity of indiscernibles and theory of space and time. Furthermore, since chapters one and two show how the activity of God is presupposed by Leibniz's metaphysics, for Leibniz to derive his metaphysics from his logic, as some would have us suppose, he would have to provide a satisfactory a priori demonstration of God's existence. But this, I argue, he cannot do. Thus God's existence and rationality, rather than subject-predicate logic, are the foundations of Leibniz's metaphysics. ;It is commonplace, when writing about Leibniz, to give primacy to his logic over his metaphysics, and indeed to try to assimilate the latter to the former. In this essay, however, I give priority to Leibniz's metaphysical pronouncements, apart, as much as possible, from logical and linguistic considerations. (shrink)

According to the Principle of Sufficient Reason (henceforth ‘PSR’), everything has an explanation or sufficient reason. This paper addresses three questions. First, how continuous is the contemporary notion of grounding with the notion of sufficient reason endorsed by Spinoza, Leibniz, and other rationalists? In particular, does a PSR formulated in terms of ground retain the intuitive pull and power of the PSR endorsed by the rationalists? Second, to what extent can the PSR avoid the formidable traditional (...) objections levelled against it if it is formulated in terms of ground? And finally, how might historical discussion of the PSR shed light on the contemporary notion of grounding? (shrink)

I argue that Leibniz's treatment of void or empty space in the appendix to his fourth letter to Clarke conflicts with the way he elsewhere treats (metaphysical) evil, insofar as he allows that God has created a world with the one kind of privation (evil), while insisting that God would not have created a world with the other kind of privation (void). I consider three respects in which the moral case might be thought to differ relevantly from the physical one, (...) and argue that none of them succeed in removing the inconsistency. Rather than denying the existence of void, Leibniz should have been led by his treatment of evil to realize that the arguments he deploys in this appendix are dubious, and that the principles to which he appeals do not rule out empty space any more than they rule out evil, darkness, cold, or any other privations. (shrink)

I distinguish three ways in which early modern rationalists seek to apply the principle of sufficient reason to empirical science, and critically assess some of their attempts to do so. I focus especially on how these thinkers assume substantive theories of explanation and intelligibility--which are indebted to the mechanist and experimentalist traditions--in many of their deployments of this rationalist principle. A recurring problem is that these philosophers deploy their standards of intelligibility inconsistently: some of their own favored (...) explanations do not always live up to their standards. I argue that the problem is especially acute for Leibniz and Euler, given their enthusiasm for final-causal explanations. (shrink)

To sum up the main results of this study: I have disentangled two distinct patterns of argument that Taylor runs together in his attempt to show that there is a reason or explanation for the world as a whole. The first is based on the causal dependency of things in the world, the second is based on their logical contingency. It seems to make the most sense of Taylor's discussion if we interpret him not as invoking the principle of (...) sufficient reason at the crucial juncture, but as using these arguments to give backing to that principle by showing that it applies to the world in its totality. However, these arguments do not succeed in doing that. The first fails because it depends on a remote analogy between the world as a whole and the physical objects in the world. Concerning the second, an analysis of the logic of why-questions about the existence of things has revealed that the logical contingency of something is not a ground for thinking it has an explanation. The only promising interpretation of the principle of sufficient reason that we have found is as a causal principle pertaining to things in nature. (shrink)

This chapter contains sections titled: The Cosmological Argument of Leibniz and Clarke Ontological Arguments and the Concept of a Necessary Being Why Not a Self‐Existent Universe? The Contestable Principle of Sufficient Reason Concluding Remarks.

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. (shrink)

The Principle of Sufficient Reason is a powerful and controversial philosophical principle stipulating that everything must have a reason or cause. This simple demand for thoroughgoing intelligibility yields some of the boldest and most challenging theses in the history of metaphysics and epistemology. In this entry we begin with explaining the Principle, and then turn to the history of the debates around it. A section on recent discussions of the Principle will be added in the (...) near future. (shrink)

Alexander Pruss’s Principle of Sufficient Reason states that every contingent true proposition has an explanation. Pruss thinks that he can plausibly maintain both his PSR and his account of libertarian free will. This is because his libertarianism has it that contingent true propositions reporting free choices are self-explanatory. But I don’t think Pruss can plausibly maintain both his PSR and libertarianism without a rift occurring in one or the other. Similar to the old luck/randomness objection, I contend that (...) Pruss’s libertarianism is susceptible to what I call “the inexplicability objection”, which attempts to show that agents’ free choices involve contingent brute facts. Pruss may be able to partially explain a proposition such that Jones freely chose A for reason R, but he cannot adequately explain a contrastive proposition such as that Jones freely chose A for R rather than B for R*. The result is that either PSR is too explanatorily permissive for libertarianism, or libertarianism is too explanatorily impermissive to satisfy PSR. After considering what I take to be Pruss’s best response to the inexplicability objection, I conclude that his attempt to reconcile PSR and libertarianism is unsuccessful. (shrink)

This essay argues for the contingency of necessity. The thesis is that contingency constitutes the possibility of necessity, which is always subsequent to contingency, only contingent necessity, a mere modality of contingent being. This study posits the contingency of necessity through a reading of Quentin Meillassoux and the late lectures of F. W. J. Schelling. While Meillassoux argues for the necessity of contingency, Schelling seeks to uncover the contingency at the heart of what is necessary. Although the principle of (...) sufficient reason provides the necessary conditions for something and reason itself derives necessary truths, the fact that there is reason rather than unreason is but the contingency of a fact. (shrink)

The Principle of Sufficient Reason is very seldom, if ever, referred to in the works of whom we might think of as the eminent Asian metaphysicians. In spite of this, the big picture metaphysical views available in the thought of philosophers such as Nāgārjuna, Fazang and Nishida appear to share certain structural features with views more familiar to us from our own tradition; views that explicitly accept or reject the Principle of Sufficient Reason. Nāgārjuna looks to (...) develop a kind of metaphysical infinitism, Fazang an extreme form of coherentism, and Nishida a species of foundationalism. These three positions - infinitism, coherentism and foundationalism - are typically thought to exhaust the spread of possibilities by those working within the Western tradition. -/- In spite of their similarities to positions advanced within our own tradition, the cosmologies of many of the giants of Asian philosophy are characterised by their rather striking conclusions. Amongst such conclusions for Nāgārjuna is that everything is empty; for Fazang that everything is identical to everything else; and for Nishida that everything depends on absolute nothingness. If the Principle of Sufficient Reason is playing a role in the derivation of such striking conclusions, then it looks that there are more options regarding the metaphysical structure of the world available to us than our own tradition typically courts. If, on the other hand, these striking cosmological conclusions are arrived at without any consideration of sufficient reason, then there may well be ways of reasoning about the overarching structure of reality that are powerful but unfamiliar to Western thinking. In this contribution, I explore what, if any, role the PSR might be playing in the thought of Nāgārjuna , Fazang and Nishida, and what we might be able to learn from it. (shrink)

1. A substance is a being that is capable of action. It is either •simple, meaning that it has no parts, or •composite, meaning that it is a collection of simple substances or monads. (Monas is a Greek word meaning ‘unity’ or ‘oneness’.) Any composite thing—any body—is a multiplicity, ·a many, but simple substances are unities, ·or ones·. There must be simple substances everywhere, because without simples there would be no composites—·without ones there could not be manies·. And simple substances (...) are lives, souls, minds—·where there is a simple substance there is life·—and the world’s being full of such substances means that the whole of nature is full of life. (shrink)

Leibniz, and many following him, saw the Principle of Sufficient Reason (PSR) as pivotal to a scientific (demonstrated) metaphysics. Against this backdrop, Kant is expected to pay close attention to PSR in his reflections on the possibility of metaphysics, which is his chief concern in the Critique of Pure Reason. It is far from clear, however, what has become of PSR in the Critique. On one reading, Kant has simply turned it into the causal principle of the (...) Second Analogy. On a different reading, PSR is but the supreme principle of reason, which roughly states that, if the conditioned is given, so is the unconditioned. On my reading, PSR appears in the guises of both the causal principle and the supreme principle. This twofold specification, I argue, is key to understanding (i) Kant’s allegations that past metaphysicians failed to prove PSR, (ii) his own Critical account of the possibility of metaphysics in both of its parts (ontology and metaphysics proper), and (iii) his nuanced answer to the contentious question about the relation between physical inquiry and metaphysical reasoning about nature (both being quests for reasons). (shrink)

How many formulations of Principle of Sufficient Reason can one find in Leibniz's works? This paper suggests that there are at least two different formulations, which start from different basic concepts, trying to sketch the relations between them and the evolution from the more ancient formulation to the mature one.

Kant's attack on metaphysics consists in large part in his attack on a principle that he names the Supreme Principle of Pure Reason. This principle, it is not often noticed, is the Principle of Sufficient Reason [PSR]. In interpreting this principle as such, I argue that Kant's attack on the PSR depends on Kant's claim that existence is not a first-order predicate. If existence isn't what Kant calls a real predicate, the PSR is false. (...) While this constitutes a powerful Kantian argument against dogmatic rationalism, it also poses a problem for Kant. For, as I argue, if the PSR is true, Kant's argument that existence isn't a first-order predicate is false. In this sense, Kant's attack on the PSR is begging the question vis-á-vis radical metaphysicians. Concluding the paper I suggest relying on Kant's 'is'/'ought' distinction in avoiding this circularity, thereby reinforcing the Kantian critique. (shrink)

The early modern period was the natural historical habitat of the Principle of Sufficient Reason, i.e., the demand that everything must have a cause, or reason. It is in this period that the principle was explicitly articulated and named, and throughout the period we find numerous formulations and variants of the PSR and its closely related ‘ex nihilo nihil fit’ principle, which the early moderns inherited from medieval philosophy. Contemporary discussions of these principles were not restricted (...) to philosophy. “Nothing will come of nothing; speak again” old King Lear tells his daughter Cordelia at the beginning of Shakespeare’s celebrated tragedy, and in early modern science, conservation principles were the order of the day. Within philosophy, Malebranche stipulates that there cannot be an effect without a cause, and Berkeley motivates his idealism by an appeal to ‘ex nihilo nihil fit.’ Were we to try to provide an exhaustive survey the various formulations of the PSR in this period – including the weaker ones – we would be writing an encyclopedia. In fact, one wonders whether any early modern thinker was willing to accept a wholesale rejection of the PSR, i.e., a view which states that no fact requires an explanation. Moreover, the view that many – perhaps most – facts require an explanation seems to be tacitly assumed even by us today, in both our theoretical and colloquial discourse. For these reasons, this chapter will focus on two early modern philosophers who advocated very strong (i.e., virtually exceptionless) versions of the PSR: Benedict de Spinoza and G.W. Leibniz. Following a brief overview of Descartes’s restricted endorsement of the PSR, I will turn to discuss the central features of the PSR in the writings of Spinoza (§2) and those of Leibniz (§3). In the cases of each of these philosophers, we will examine carefully: (i) their main statements of the PSR, (ii) the scope they assign to the principle (i.e., what requires an explanation and what counts as an explanation), (iii) the modal strength they assign to the principle, (iv) the main implications they draw from the principle, (v) exceptions to the principle, and, finally, (vi) the justification of the principle. In §4, we will study a principle, complementing the PSR, namely, the assertion that everything and every fact must have an effect (or as Leibniz would put it: “nothing is sterile”). (shrink)

The principle of sufficient reason threatens modal collapse. Some have suggested that by appealing to the indefinite extensibility of contingent truth, the threat is neutralized. This paper argues that this is not so. If the indefinite extensibility of contingent truth is developed in an analogous fashion to the most promising models of the indefinite extensibility of the concept set, plausible principles permit the derivation of modal collapse.

I examine Leibniz’s version of the Principle of Sufficient Reason with respect to free will, paying particular attention to Peter van Inwagen’s argument that this principle leads to determinism. Ultimately I conclude that Leibniz’s formulation is incompatible with free will. I then discuss a reformulation of the Principle of Sufficient Reason endorsed by Alexander Pruss that, I argue, manages to both retain the strength of Leibniz’s formulation and remain consistent with free will.

In Section 21 of his fifth letter to Clarke Leibniz attempts to derive the Identity of Indiscernibles from an application of the Principle of Sufficient Reason to God´s act of creation, namely that God has a reason to create the world he creates. In this paper I argue that this argument fails, not just because the Identity of Indiscernibles is false, but because there is a counterexample to one of the premises that Leibniz cannot satisfactorily rule out.