This volume contains more than 60 original translations of papers written by the German philosopher Gottfried Wilhelm Leibniz (1646-1716). As well as contributing to Leibniz scholarship, it is intended to function as an introductory text for students.

In the Discourse on Metaphysics Leibniz put forward his famous complete-concept definition of substance. Sometimes this definition is glossed as stating that a substance is an entity with a concept so complete that it contains all its predicates, and it is thought that it follows directly from Leibniz’s theory of truth. Now, an adequate definition of substance should not apply to accidents. But, as I shall point out, if Leibniz’s theory of truth is correct then an accident is an (...) entity with a concept so complete that it contains all its predicates. The aim of this paper is to clarify Leibniz’s notion of substance in the Discourse with a view to explaining how that definition successfully distinguishes between substances and accidents. (shrink)

This paper explores the relationships between perception, representation and appetition in Leibniz's later metaphysics, and defends four theses. First, for Leibniz perceptions are not the carriers of content, but they are identical to representational content. Second, Leibniz's appetitions are the carriers of content and he should be taken at his word when he declares, "Thought consists in conatus". Third, while it is true that for Leibniz representational content is determined by a species of mapping or function from (...) representation to what is represented, this is not the only component that determines representational content for Leibniz. The correspondence in terms of which Leibniz characterizes representation includes an ontological component, namely a lineage or trace from representation to represented object via God's creation, and appetitions constitute this trace. Finally, Leibniz's account of how ideas represent and how perceptions represent are distinct, and derivation plays a key role in how ideas represent. (shrink)

In this paper I offer a discussion of chapter 3 of Adrian Moore’s The Evolution of Modern Metaphysics, which is titled “Leibniz: Metaphysics in the Service of Theodicy.” Here Moore discusses the philosophy of Leibniz and comes to a damning conclusion. My main aim is to suggest that such a conclusion might be a little premature. I begin by outlining Moore’s discussion of Leibniz and then raise some problems for the objections that Moore presents. I follow this by (...) raising a Moore-inspired problem of my own and offer a possible response. The response is based on a little-known essay of Leibniz’s called “Leibniz’s Philosophical Dream” and leads me to consider Leibniz’s deepest motivations for engaging in philosophical reflection. (shrink)

Leibniz claims that for every possible substance S there is an individual concept that includes predicates describing everything that will ever happen to S, if S existed. Many commentators have thought that this leads Leibniz to think that all properties are had essentially, and thus that it is not metaphysically possible for substances to be otherwise than the way their individual concept has them as being. I argue against this common way of reading Leibniz’s views on the metaphysics of (...) modality. I develop a model in which individual concepts are innocent; that is, individual concepts are divine ideas that permit God to know everything that will ever happen to all possible substances, if created, but these individual concepts neither require that all properties are had essentially nor require that it is metaphysically necessary for substances to be the way their individual concepts have them as being. (shrink)

Drawing on remarks scattered through his writings, I argue that Leibniz has a highly distinctive and interesting theory of color. The central feature of the theory is the way in which it combines a nuanced subjectivism about color with a reductive approach of a sort usually associated with objectivist theories of color. After reconstructing Leibniz's theory and calling attention to some of its most notable attractions, I turn to the apparent incompatibility of its subjective and reductive components. I argue (...) that this apparent tension vanishes in light of his rejection of a widely accepted doctrine concerning the nature of bodies and their geometrical qualities. (shrink)

In Leibniz’s New Essays stands out, within many important topics, his doctrine of innate ideas, which supposes the division between sense knowledge and innate knowledge and implies the distinction between truths of reason and truths of fact. That doctrine is particularly relevant for Leibniz’s philosophy, but implicitly entails the epistemological difference between belief, on one hand, and certainty, on the other. In this paper I outline, according to my interpretation, how Leibniz explains that humans can have certainty about innate ideas. (...) This topic is important because if Leibniz demonstrates the possibility of having certainty of those ideas, then, it is feasible to believe in its existence. However, if his explanation is unsatisfactory his metaphysical doctrine would be seriously weakened and, at the same time, both skepticism and Locke’s empiricist doctrine would be reinforced. (shrink)

This paper explores the development of Leibniz’s metaphysics of the Incarnation in the context of his philosophy. In particular it asks to what extent Leibniz’s repeated endorsement of the traditional analogy between the union in humankind of soul (mind) and body, and the union in Christ of divine and human natures, could be accommodated by his more general metaphysical doctrines. Such an investigation highlights some of the deepest commitments in Leibniz’s theory of substance as well as detect in it (...) some unresolved tensions. The paper comes to the conclusion that puzzling points of Leibniz’s metaphysics of the Incarnation, rather than being problems specific to his theology, uncover tensions in his theory of substance as such – tensions converging on the vexed question of whether there can or cannot be genuine corporeal substances in Leibniz’s mature philosophy. (shrink)

The category of metaphysical evil introduced by Leibniz appears to cast a sinister shadow over the goodness of creation. It seems to imply that creatures, simply in virtue of not being gods, are to some degree intrinsically and inescapably evil. After briefly unpacking this difficulty and outlining a recent attempt to deal with it, this paper returns to the texts to propose a novel and multilayered understanding of Leibniz’s category of metaphysical evil by reading it against the backdrop of the (...) traditional typologies of evil with which he was unquestionably familiar. It comes to the conclusion that metaphysical evil plays two key roles for Leibniz. First, it captures what Aquinas and especially Suarez meant by ‘natural evil’. Contrary to the common assumption that it is Leibniz’s category of physical evil that holds the place of natural evil, the paper shows that Leibniz’s physical evil corresponds to Augustine’s category of evil of punishment for sin whereas natural evil – intended as a kind of evil which is not related to moral responsibility -- is subsumed under metaphysical evil. Secondly, the category of metaphysical evil covers also the notion of original creaturely imperfection. In classifying creaturely limitation as a kind of evil Leibniz breaks from the Augustinian-Thomist-Scholastic tradition and its distinction between negatio and privatio. On the other hand, notwithstanding this important break, Leibniz’s notion of metaphysical evil is intended to account for something which is firmly within the broadly Augustinian-Scholastic tradition, namely the ascription to all creatures of a limitation that stems from their being created ex nihilo. Finally, the paper returns a verdict of non-guilty to the charge that Leibniz’s metaphysical evil implies that creatures qua creatures are to some extent necessarily intrinsically evil. More generally, in typical Leibnizian fashion, the notion of metaphysical evil will appear to be a complex mix of indebtedness to tradition and bending of received doctrines into something significantly different. (shrink)

This essay develops a interpretation of Leibniz’ theory of motion that strives to integrate his metaphysics of force with his doctrine of the equivalence of hypotheses, but which also supports a realist, as opposed to a fully idealist, interpretation of his natural philosophy. Overall, the modern approaches to Leibniz’ physics that rely on a fixed spacetime backdrop, classical mechanical constructions, or absolute speed, will be revealed as deficient, whereas a more adequate interpretation will be advanced that draws inspiration from (...) an invariantist conception of reality and recent non-classical theories of physics. (shrink)

There was a consensus in late Scholasticism that evils are privations, the lacks of appropriate perfections. For something to be evil is for it to lack an excellence that, by its nature, it ought to have. This widely accepted ontology of evil was used, in part, to help explain the source of evil in a world created and sustained by a perfect being. during the second half of the seventeenth century, progressive early moderns began to criticize the traditional privative account (...) of evil on a variety of philosophical and theological grounds. Embedded in Scholastic Aristotelianism and applied to problems of evil, privation theory seemed to some like yet another instance of pre-modern pseudo-explanation.1Against this .. (shrink)

Requirement specifications in software engineering involve developing a conceptual model of a target domain. The model is based on ontological exploration of things in reality. Many things in such a process closely tie to problems in metaphysics, the field of inquiry of what reality fundamentally is. According to some researchers, metaphysicians are trying to develop an account of the world that properly conceptualizes the way it is, and software design is similar. Notions such as classes, object orientation, properties, instantiation, (...) algorithms, etc. are metaphysical concepts developed many years ago. Exploring the metaphysics of such notions aims to establish quality assurance though some objective foundation not subject to misapprehensions and conventions. Much metaphysical work might best be understood as a model-building process. Here, a model is viewed as a hypothetical structure that we describe and investigate to understand more complex, real-world systems. The purpose of this paper is to enhance understanding of the metaphysical origins of conceptual modeling as exemplified by a specific proposed high-level model called thinging machines (TMs). The focus is on thimacs (things/machine) as a single category of TM modeling in the context of a two-phase world of staticity and dynamics. The general idea of this reality has been inspired by Deleuze’s ‘the virtual’ and related to the classical notions of Leibniz’s monads and Avicenna’s essence. The analysis of TMs leads to several interesting results about a thimac’s nature at the static and existence levels. (shrink)

This article discusses some reasons for taking a reconstructive approach to the argumentative structure of Leibniz’s metaphysics. One reason is the fragmentary nature of the countless notes and letters that constitute by far the largest part of Leibniz‘s philosophical output. Another reason is that conjecturing how the many isolated arguments proposed by Leibniz fit into a large-scale argumentative structure could yield insights into how Leibniz made use of the method of intuition – both in his analysis of mind and (...) in his analysis of matter. Contemporary critics have objected that the method of intuition leads to philosophical conservatism, arbitrary choices between conflicting intuitions, and a preoccupation with psychological facts rather than with reality. By contrast, reconstructing the methodology behind Leibniz’s metaphysics could indicate how intuitions could be used in a way that sidesteps these problems. Leibniz gives priority to intuitions concerning the structure of mental operations over intuitions concerning the structure of material objects; this is why intuitions concerning the structure of material objects can be replaced by innovative philosophical theories; these theories, however, make use of metaphysical concepts implied by the analysis of mind and, thereby, can capture facts both about psychology and about the structure of extra-mental reality. (shrink)

This paper attempts to resolve the puzzle associated with the non-spatiality of monads by investigating the possibility that Leibniz employed a version of the extension of power doctrine, a Scholastic concept that explains the relationship between immaterial and material beings. As will be demonstrated, not only does the extension of power doctrine lead to a better understanding of Leibniz’ reasons for claiming that monads are non-spatial, but it also supports those interpretations of Leibniz’ metaphysics that accepts the real extension (...) of bodies. (shrink)

This anthology is about the signal change in Leibniz’s metaphysics with his explicit adoption of substantial forms in 1678-79. This change can either be seen as a moment of discontinuity with his metaphysics of maturity or as a moment of continuity, such as a passage to the metaphysics from his last years. Between the end of his sejour at Paris and the first part of the Hanover period, Leibniz reformed his dynamics and began to use the theory (...) of corporeal substance. This book explores a very important part of the philosophical work of the young Leibniz. Expertise from around the globe is collated here, including Daniel Garber’s work based on the recent publication of Leibniz's correspondence from the late 1690s, examining how the theory of monads developed during these crucial years. Richard Arthur argues that the introduction of substantial forms, reinterpreted as enduring primitive forces of action in each corporeal substance, allows Leibniz to found the reality of the phenomena of motion in force and thus avoid reducing motion to a mere appearance. Amongst other themes covered in this book, Pauline Phemister’s paper investigates Leibniz’s views on animals and plants, highlighting changes, modifications and elaborations over time of Leibniz’s views and supporting arguments and paying particular attention to his claim that the future is already contained in the seeds of living things. The editor, Adrian Nita, contributes a paper on the continuity or discontinuity of Leibniz’s work on the question of the unity and identity of substance from the perspective of the relation with soul and mind. (shrink)

Leibniz accepts causal independence, the claim that no created substance can causally interact with any other. And Leibniz needs causal independence to be true, since his well-known pre-established harmony is premised upon it. So, what is Leibniz’s argument for causal independence? Sometimes he claims that causal interaction between substances is superfluous. Sometimes he claims that it would require the transfer of accidents, and that this is impossible. But when Leibniz finds himself under sustained pressure to defend causal independence, those are (...) not the reasons that he marshals in its defense. Instead, deep into his long correspondence with Burchard de Volder, he gives a different sort of argument, one that has gone nearly unnoticed by commentators and has not yet been properly understood. In part, this is because the argument develops slowly over four years of correspondence. It emerges in early 1704, but it is formulated tersely and appears murky unless understood in light of Leibniz and De Volder’s tangled exchanges. There Leibniz argues that, on his distinctive ontology of an infinity of created substances, no two created substances could possibly causally interact, for roughly the same reasons that some Cartesians like De Volder deny interaction between minds and bodies on their substance dualist ontology. In this paper I draw out this lost argument, explain it and the metaphysics on which Leibniz builds it, and untangle Leibniz and De Volder’s exchanges concerning causation from which this argument results. (shrink)

Leibniz thinks that every created substance is causally active, and yet causally independent of every other: none can cause changes in any but itself. This is not controversial. But Leibniz also thinks that every created substance is existentially independent of every other: it is metaphysically possible for any to exist with or without any other. This is controversial. I argue that, given a mainstream reading of Leibniz’s essentialism, if one accepts the former, uncontroversial interpretation concerning causal independence, then one ought (...) also to accept the latter, controversial one concerning existential independence. This is a new way to defend the ‘existential independence’ interpretation. Moreover, this defense provides a new approach for defending the broadly ‘non-logical’ interpretive camp in the longstanding debate over Leibniz’s views on incompossibility, against perhaps the strongest objection leveled by advocates of the opposing broadly ‘logical’ interpretation. (shrink)

Leibniz frequently uses the notion of expression, but it is not easy to see just how he understood that relation. This paper focuses on the particular case of the expression of God, which is prominent in the 'Discourse on Metaphysics'. The treatment of expression there suggests several questions. Which substances did Leibniz believe expressed God? Why did Leibniz believe those substances expressed God? And did he believe that all substances expressed God in the same way and for the same (...) reasons? In answering those questions the paper distinguishes two views about expression in the 'Discourse', considers Leibniz's reasons for holding that substances express their causes, and argues that Leibniz's views about emanative causation are important for understanding the unity of his apparently distinct views here. The paper concludes by looking briefly at how the 'Discourse' fits into the evolution of Leibniz's views on this issue over time. (shrink)

Leibniz claims that God acts in the best possible way, and that this includes creating exactly one world. But worlds are aggregates, and aggregates have a low degree of reality or metaphysical perfection, perhaps none at all. This is Leibniz’s tendency toward acosmism, or the view that there this no such thing as creation-as-a-whole. Many interpreters reconcile Leibniz’s acosmist tendency with the high value of worlds by proposing that God sums the value of each substance created, so that the best (...) world is just the world with the most substances. I call this way of determining the value of a world the Additive Theory of Value (ATV), and argue that it leads to the current and insoluble form of the problem of incompossibility. To avoid the problem, I read “possible worlds” in “God chooses the best of all possible worlds” as referring to God’s ideas of worlds. These ideas, though built up from essences, are themselves unities and so well suited to be the value bearers that Leibniz’s theodicy requires. They have their own value, thanks to their unity, and that unity is not preserved when more essences are added. (shrink)

Our computational metaphysics group describes its use of automated reasoning tools to study Leibniz’s theory of concepts. We start with a reconstruction of Leibniz’s theory within the theory of abstract objects (henceforth ‘object theory’). Leibniz’s theory of concepts, under this reconstruction, has a non-modal algebra of concepts, a concept-containment theory of truth, and a modal metaphysics of complete individual concepts. We show how the object-theoretic reconstruction of these components of Leibniz’s theory can be represented for investigation by means (...) of automated theorem provers and finite model builders. The fundamental theorem of Leibniz’s theory is derived using these tools. (shrink)

The reconstruction of Leibniz’s metaphysics that Deleuze undertakes in The Fold provides a systematic account of the structure of Leibniz’s metaphysics in terms of its mathematical foundations. However, in doing so, Deleuze draws not only upon the mathematics developed by Leibniz—including the law of continuity as reflected in the calculus of infinite series and the infinitesimal calculus—but also upon developments in mathematics made by a number of Leibniz’s contemporaries—including Newton’s method of fluxions. He also draws upon a number (...) of subsequent developments in mathematics, the rudiments of which can be more or less located in Leibniz’s own work—including the theory of functions and singularities, the Weierstrassian theory of analytic continuity, and Poincaré’s theory of automorphic functions. Deleuze then retrospectively maps these developments back onto the structure of Leibniz’s metaphysics. While the Weierstrassian theory of analytic continuity serves to clarify Leibniz’s work, Poincaré’s theory of automorphic functions offers a solution to overcome and extend the limits that Deleuze identifies in Leibniz’s metaphysics. Deleuze brings this elaborate conjunction of material together in order to set up a mathematical idealization of the system that he considers to be implicit in Leibniz’s work. The result is a thoroughly mathematical explication of the structure of Leibniz’s metaphysics. This essay is an exposition of the very mathematical underpinnings of this Deleuzian account of the structure of Leibniz’s metaphysics, which, I maintain, subtends the entire text of The Fold. (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)

According to the most prominent principle of early modern rationalists, the Principle of Sufficient Reason [PSR], there are no brute facts, hence, there are no facts without any explanation. Contrary to the PSR, some philosophers have argued that divine ideas are brute facts within Leibniz’s metaphysics. In this paper, I argue against brute-fact-theories of divine ideas, especially represented by Samuel Newlands in Leibniz and the Ground of Possibility, and elaborate an alternative Leibnizian theory of divine ideas.

Leibniz' first problem with contingency stems from his doctrine of divine creation (not his later doctrine of truth) and is solved via his concepts of necessity per se, etc. (not via his later concept of infinite analysis). I scrutinize some of the earliest texts in which the first problem and its solution occur. I compare his "per se modal concepts" with his concept of analysis and with the traditional concept of metaphysical necessity. I then identify and remove the main obstacle (...) to Leibniz' employment of these concepts by reflecting on his concept of a world and comparing and contrasting it with contemporary conceptions. Finally I sketch the place that this early problem and its solution had in the context of his mature philosophy. A disagreement between Sleigh and Adams which hinges on the assumption that there is just one problem with competing solutions is seen to dissolve in this light. (shrink)

Leibniz's World-Apart Doctrine states that every created substance is independent of everything except God. Commentators have connected the independence of substance asserted by World-Apart to a variety of important aspects of Leibniz's modal metaphysics, including his theory of compossibility and his notion of a possible world (including what possible worlds there are). But what sort of independence is at stake in World-Apart? I argue that there is not a single sense of "independence" at stake, but at least (...) three: what I call "causal", "phenomenal", and "ontological" independence. Further, I distinguish two versions of each type of independence: what I call "basic" and "strict" versions. I argue that only basic versions can be legitimately attributed to Leibniz. In light of this result, I conclude, pace previous commentators, that World-Apart has little impact on Leibniz's modal metaphysics. (shrink)

A review of Futch's book on Leibniz' natural philosophy of time and space.

This paper reconsiders Leibniz’s conception of the nature of possible things and offers a novel interpretation of the actualization of possible substances. This requires analyzing a largely neglected notion, the reality of individual essences. Thus far scholars have tended to construe essences as representational items in God’s intellect. We acknowledge that finite essences have being in the divine intellect but insist that they are also grounded in the infinite essence of God, as limitations of it. Indeed, we show that it (...) is critical to understand that this dependence on God’s essence is prior to the dependence on God through divine ideas. Here it is crucial to distinguish questions concerning the ontological status of essences from questions concerning their reality. This yields a fresh view of Leibniz’s theory of creation, which takes seriously his claim that the same thing is first a mere possibility but after creation an actually existent substance. (shrink)

The analysis of Leibniz’s heritage and phenomenology of virtuality in the title of this conference do not exhaust the whole variety of topics, but rather are the poles between which the discussion has been developing. Monadology of Leibniz became the place of concurrence of absolute identity and unique ecstatic that gave rise to a specific discourse of virtuality.

Leibniz frequently argued that reasons are to be weighed against each other as in a pair of scales, as Professor Marcelo Dascal has shown in his article "The Balance of Reason." In this kind of weighing it is not necessary to reach demonstrative certainty – one need only judge whether the reasons weigh more on behalf of one or the other option However, a different kind of account about rational decision-making can be found in some of Leibniz's writings. In (...) his article "Was Leibniz's Deity an Akrates?" Professor Jaakko Hintikka has argued that Leibniz developed a new vectorial model for rational decisions which is better suited to complicated decisions, where values are complementary to each other. This model, related closely to his work in metaphysics and the philosophy of mind, is a heuristic device which helps in finding rational combinations - and in an ideal case an optimum - between plural inclinations to the good. I shall argue that Leibniz applies more or less implicitly both of these models in his practical rationality. In simple situations he applied the pair of scales model and in more complicated situations he applied the vectorial model. (shrink)

To explain why God is not the author of sin, despite grounding all features of the world, the early Leibniz marginalized the divine will and defined existence as harmony. These moves support each other. It is easier to nearly eliminate the divine will from creation if existence itself is something wholly intelligible, and easier to identify existence with an internal feature of the possibles if the divine will is not responsible for creation. Both moves, however, commit Leibniz to a necessitarianism (...) that is stronger than what prominent interpreters such as Robert Sleigh and Mogens Lærke have found in the early Leibniz, and stronger than the necessitarianism that threatens his later philosophy. I defend this reading of Leibniz and propose that some features of Leibniz’s later metaphysics, including his “striving possibles” doctrine, are an artifact of the effort to rescue the early theodicy from its unwelcome implications. (shrink)

Our computational metaphysics group describes its use of automated reasoning tools to study Leibniz’s theory of concepts. We start with a reconstruction of Leibniz’s theory within the theory of abstract objects (henceforth ‘object theory’). Leibniz’s theory of concepts, under this reconstruction, has a non-modal algebra of concepts, a concept-containment theory of truth, and a modal metaphysics of complete individual concepts. We show how the object-theoretic reconstruction of these components of Leibniz’s theory can be represented for investigation by means (...) of automated theorem provers and finite model builders. The fundamental theorem of Leibniz’s theory is derived using these tools. (shrink)

Explications of the reconstruction of Leibniz’s metaphysics that Deleuze undertakes in 'The Fold: Leibniz and the Baroque' focus predominantly on the role of the infinitesimal calculus developed by Leibniz.1 While not underestimat- ing the importance of the infinitesimal calculus and the law of continuity as reflected in the calculus of infinite series to any understanding of Leibniz’s metaphysics and to Deleuze’s reconstruction of it in The Fold, what I propose to examine in this paper is the role played (...) by other developments in mathematics that Deleuze draws upon, including those made by a number of Leibniz’s near contemporaries – the projective geometry that has its roots in the work of Desargues (1591–1661) and the ‘proto-topology’ that appears in the work of Du ̈rer (1471–1528) – and a number of the subsequent developments in these fields of mathematics. Deleuze brings this elaborate conjunction of material together in order to set up a mathematical idealization of the system that he considers to be implicit in Leibniz’s work. The result is a thoroughly mathematical explication of the structure of Leibniz’s metaphysics. What is provided in this paper is an exposition of the very mathematical underpinnings of this Deleuzian account of the structure of Leibniz’s metaphysics, which, I maintain, subtends the entire text of The Fold. (shrink)

Our examination explicates not only how Leibniz’s emphasis on force or power squares well with (and most probably largely stems from) his endorsement of certain central Aristotelian tenets, but also how the concept of force is incorporated into his mature idealist metaphysics. That metaphysics, in turn, generates some thorny problems with regard to the concept of passivity; and so we shall also ask whether and how Leibniz’s monadology, emphasizing the activity as much as it does, is able to (...) encompass the passivity of created substances. (shrink)

Recently we proposed "quantum language" (or, the linguistic Copenhagen interpretation of quantum mechanics"), which was not only characterized as the metaphysical and linguistic turn of quantum mechanics but also the linguistic turn of Descartes=Kant epistemology. We believe that quantum language is the language to describe science, which is the final goal of dualistic idealism. Hence there is a reason to want to clarify, from the quantum linguistic point of view, the following problems: "brain in a vat argument", "the Cogito proposition", (...) "five-minute hypothesis", "only the present exists", "Copernican revolution", "McTaggart's paradox", and so on. In this paper, these will be discussed and clarified in quantum language. That is, these are not in quantum language. Also we emphasize that Leibniz's relationalism in Leibniz-Clarke correspondence is regarded as one of the most important parts of the linguistic Copenhagen interpretation of quantum mechanics. This paper is the revised version of the paper: Open Journal of Philosophy, 2018 Vol.8, No.5, 466-480). (shrink)

Neuere Interpretationen von Leibniz' Notizen zur Metaphysik aus den Jahren 1675-1676 tendieren dazu, diese Texte im Licht eines spinozistischen Substanz-Monismus zu lesen. Obwohl es für eine solche Interpretation überzeugende Anhaltspunkte gibt, vertritt Leibniz jedoch in denselben Texten auch einen Substanzen-Pluralismus in Bezug auf geistige Substanzen. Substanz-Monismus und Substanzen-Pluralismus scheinen miteinander vereinbar zu sein, weil für Leibniz, ähnlich wie für Descartes in den Principia philosophiae, der Terminus ‚Substanz‛ nicht in univoker Weise von Gott und von Gegenständen in der Welt ausgesagt werden (...) kann. (shrink)

This paper explores the question of Leibniz’s contribution to the rise of modern ‘science’. To be sure, it is now generally agreed that the modern category of ‘science’ did not exist in the early modern period. At the same time, this period witnessed a very important stage in the process from which modern science eventually emerged. My discussion will be aimed at uncovering the new enterprise, and the new distinctions which were taking shape in the early modern period under the (...) banner of the old Aristotelian terminology. I will argue that Leibniz begins to theorize a distinction between physics and metaphysics that tracks our distinction between the autonomous enterprise of science in its modern meaning, and the enterprise of philosophy. I will try to show that, for Leibniz, physics proper is the study of natural phenomena in mathematical and mechanical terms without recourse for its explanations to metaphysical notions. This autonomy, however, does not imply for Leibniz that physics can say on its own all that there is to be said about the natural world. Quite the opposite. Leibniz inherits from the Aristotelian tradition the view that physics needs metaphysical roots or a metaphysical grounding. For Leibniz, what is ultimately real is reached by metaphysics, not by physics. This is, in my view, Leibniz’s chief insight: the new mathematical physics is an autonomous enterprise which offers its own kind of explanations but does not exhaust what can (and should) be said about the natural world. (shrink)

I show that Leibniz’s account of divine concurrence is constrained in a surprising way by his commitment to the Principle of Sufficient Reason, where a sufficient reason for the existence of an entity or a state of affairs is understood to be the totality of requisites for its existence. I argue first that Leibniz endorses, in both his early and later metaphysics, the ‘totality of requisites’ conception of sufficient reason. I then show that this conception gives rise to a (...) distinctive and underappreciated logical redundancy problem. Finally, I show that the logical redundancy problem can be side-stepped if we attribute to Leibniz the view that the states of any created substance are caused by God in a single act. On this view, God’s concurrence with creaturely activity is irreducibly plural: the natural effects or states of any created substance are brought about together, as a collective. I show that there are both philosophical and textual grounds for attributing such a view to Leibniz. (shrink)

G. W. Leibniz developed a new model for rational decision-making which is suited to complicated decisions, where goods do not rule each other out, but compete with each other. In such cases the deliberator has to consider all of the goods and pick the ones that contribute most to the desired goal which in Leibniz’s system is ultimately the advancement of universal perfection. The inclinations to particular goods can be seen as vectors leading to different directions much like forces in (...) Leibniz’s dynamics. The vectorial model of rational decision-making is related to Leibniz’s work with metaphysical physics and the calculus of variations and is a heuristic tool which helps in finding reasonable combinations – in ideal cases optimums - between competing goods. By applying the model, the decision-maker can map and compare outcomes of combinations of goods in question and practice a kind of pseudo-mechanical arithmetic of reasons. A central feature of the model is the possibility to employ geometrical figures to help the conceptualization. In this paper I present the vectorial model, examine its applications in practical cases from political theory, jurisprudence and ethics Leibniz presented, and compare the model to recent theories of acting under uncertainty, such as bounded rationality and optimizing under constraints. (shrink)

In this paper I will discuss the doctrine of substance which emerges from Leibniz’s unpublished early memoir De affectibus of 1679. The memoir marks a new stage in Leibniz’s views of the mind. The motivation for this change can be found in Leibniz’s rejection of the Cartesian theory of passion and action in the 1670s. His early Aristotelianism and some features of Cartesianism persisted to which Leibniz added influences from Hobbes and Spinoza. His nascent dynamical concept of substance is seemingly (...) a combination of old and fresh influences, representing a characteristically eclectic approach, but I will argue that the influence of Hobbes is especially important in the memoir. To do that, I will examine Leibniz’s development in the 1670s up to the De affectibus and consider the nature of affects in the memoir, especially the first affect which starts the thought sequence. This first affect of pleasure or pain is the key to Leibniz’s theory of active substances and in this way to the whole of Leibniz’s moral psychology and ethical metaphysics. (shrink)

In his early lecture note Versuch einiger Betrachtungen über den Optimismus (1759) a young supporter of metaphysical optimism called Immanuel Kant tested the Leibnizian optimism by posing some counter-arguments against it only to falsify them. His counter-arguments were very inventive and they feature often in modern scholarship on Leibniz. In this paper I will present Kant’s main arguments and evaluate them. I will argue that Kant’s understanding on Leibnizian optimism is little misguided and for this reason his own positive counter-argument (...) despite its ingeniousness is problematic. His second solution to the problem is comparable to the doctrine of metaphysical optimism, but fails also for the same reason as the first one. -/- . (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)

Causation was an important topic of philosophical reflection during the Seventeenth Century. This reflection centred around certain particular problems about causation, one of which was the problem of causation between mind and body. The doctrine of the pre-established harmony is Leibniz's response to the problem of causation between mind and body. In this chapter I shall (a) explain the problem of mind-body causation; (b) explain Leibniz's pre-established harmony; and (c) assess his case for it.

In this paper, we consider what is commonly referred to as Leibniz’s argument for primitive concepts. After presenting and criticizing (in sections 1 and 2) one recent rather straightforward way of interpreting this argument, by Paul Lodge and Stephen Puryear, which takes the argument to be merely about the structure of concepts, we offer an alternative way of looking at the argument. We think it is best seen as being fundamentally about the relation between thought and reality. In order to (...) prepare the ground for our reconstruction (which we present in section 5), we have to introduce his view of ideas or concepts (section 3), as well as some metaphysical principles concerning reality-dependence (section 4). (shrink)

I propose that Leibniz did not state Leibniz’s Law, the logically and metaphysically robust principle that is typically understood as the following biconditional: ∀x ∀y [(x = y) ↔ ∀P (Px ↔ Py)]. To arrive at this conclusion, I examine the three principles that have become associated with Leibniz’s Law: the Substitutivity Principle (salva veritate), the Indiscernibility of Identicals, and the Identity of Indiscernibles. I show that Leibniz intended salva veritate as a semantic principle, never explicitly stated the Indiscernibility of (...) Identicals, and understood the Identity of Indiscernibles as a metaphysical principle. In the debate about Leibniz’s Law, I focus on four commentators: (1) W. V. O. Quine’s construal of salva veritate as the Indiscernibility of Identicals, (2) Nicholas Rescher’s contention that both the Identity of Indiscernibles and salva veritate may be construed as Leibniz’s Law, (3) Fred Feldman’s argument that Leibniz did not state a law or definition of identity, but only a criterion of identity for concepts, and (4) Edwin Curley’s response to Feldman, that Feldman’s assumptions, along with passages in Leibniz, show Leibniz did state Leibniz’s Law. I argue that Feldman’s position is not completely correct but can be amended with insights from Quine, Rescher, and Curley and by reference to Leibniz’s Complete Concept Theory. (shrink)

In The Fold, Deleuze regards Raymond Ruyer as the most recent of Leibniz’s great disciples. This claim is not self-evident, since Ruyer often criticises Leibniz and stresses the divergence of his theory from Leibniz’s monadological metaphysics. Therefore, while Ruyer does not seem to regard himself as indebted to Leibniz, and as his psychobiology is not always reconcilable with Leibniz’s philosophy, it is necessary to explore what is at stake in Deleuze’s recognition of Ruyer as a Leibnizian thinker. This essay (...) foregrounds the tacit intertwining between Leibniz and Ruyer, which can, on the one hand, contribute to Leibniz’s scholarship and uncover the contemporaneity of his thought, and on the other hand, expose certain revealing Ruyerian moments in Deleuze’s immanent philosophy. (shrink)

The advance of mechanism in science and philosophy in the 17th century created a great interest to machines or automata. Leibniz was no exception - in an early memoir Drôle de pensée he wrote admiringly about a machine that could walk on water, exhibited in Paris. The idea of automatic processing in general had a large role in his thought, as can be seen, for example, in his invention of the binary code and the so-called Calculemus!-model for solving controversies. In (...) metaphysics, the idea of an automata was expressed most clearly in the 1695 article New System of the Nature of Substances and their Communication, and the ensuing correspondence with, among others, Foucher, Bayle, Lamy, Jaquelot and Masham. In the article Leibniz discusses the soul as a spiritual machine in the context of pre-established harmony, arguing that God can "give to a substance at the outset a nature or internal force which could produce in it an orderly way (as in spiritual or formal automaton; but a free one, in the case of a substance which is endowed with a share of reason) everything that is going to happen to it, that is to say, all the appearances or expressions it is going to have, and all without the help of any created thing." The basic idea of Leibniz's spiritual machine is that the soul or entelechy is an autonomous and spontaneous unity, consisting of internal active force and producing its own perceptions (both confused and distinct). It is a self-moving machine, driven by its perceptions and appetites, but it follows (without being conscious of it) a lawful series or programme created by God. The entelechy remains the same despite undergoing an infinite number of changes. To Foucher he explained that each state of the individual substance is a consequence of its preceding one, "as if there were only God and the substance in the world". Despite this, the spiritual machine is related not only to God, but through the pre-established harmony to bodies or natural machines. However, as it is not dependent on them, the spiritual machine is superiot to natural machines. In this paper I concentrate on three moral themes related to the spiritual machine: moral deliberation, moral identity and the goal of moral action. All these themes are more or less implicit in the New System, but are discussed in more detail in the ensuing correspondence after the publication of the article. Finally, the themes are given an extended discussion especially in the second book of New Essays on Human Understanding (1704, published 1765), written partly at the same time as some of the correspondence and unpublished related material. I will first give an overview of Leibniz's position concerning the spiritual machine or automaton in the New System and then go on to explore the three moral themes one by one, as they feature in the subsequent correspondence and in the New Essays. I will show that the three topics are essential to the function of the spiritual machine – to Sophie Charlotte Leibniz wrote: "...let us say that everything in bodies happens mechanically, or in accordance with laws of motion, and that everything in the soul happens morally, or in accordance with perceived good or evil." There are many texts that anticipate the views in the New System (notably the unpublished memoir De Affectibus of 1679) and Leibniz continued to discuss its themes later on (in addition to correpondence, for example, in Theodicy of 1710 and Monadology and Principles of Nature and Grace of 1714). Here I focus on the short-term development of Leibniz's views on the topic (around 1695-1705), but I argue that his basic view of the spiritual machine did not change much after finishing the dialogue with Locke in 1704. (shrink)

Despite the importance of the variational principles of physics, there have been relatively few attempts to consider them for a realistic framework. In addition to the old teleological question, this paper continues the recent discussion regarding the modal involvement of the principle of least action and its relations with the Humean view of the laws of nature. The reality of possible paths in the principle of least action is examined from the perspectives of the contemporary metaphysics of modality and (...) Leibniz's concept of essences or possibles striving for existence. I elaborate a modal interpretation of the principle of least action that replaces a classical representation of a system's motion along a single history in the actual modality by simultaneous motions along an infinite set of all possible histories in the possible modality. This model is based on an intuition that deep ontological connections exist between the possible paths in the principle of least action and possible quantum histories in the Feynman path integral. I interpret the action as a physical measure of the essence of every possible history. Therefore only one actual history has the highest degree of the essence and minimal action. To address the issue of necessity, I assume that the principle of least action has a general physical necessity and lies between the laws of motion with a limited physical necessity and certain laws with a metaphysical necessity. (shrink)