LEIBNIZ’ METAPHYSICS OF INTENTIONALITY JONATHAN CHARLES REYNOLD HILL (BA (HONS), M PHIL (OXON)) A THESIS SUBMITTED FOR THE DEGREE OF DOCTOR OF PHILOSOPHY DEPARTMENT OF PHILOSOPHY NATIONAL UNIVERSITY OF SINGAPORE 2008 i Contents Summary iii 1 Introduction 1 2 The medieval philosophers 15 The “package” 15 Thomas Aquinas 19 Henry of Ghent 49 John Duns Scotus 62 Conclusion 87 3 Leibniz and relations 89 Reducibility, reality, and the nature of rewriting projects 90 The rewriting project 108 Inter-substantial relations and relational properties 125 Extrinsic denominations 138 Incompossibility 145 Inter-relatedness and isolationism 152 Conclusion 161 4 Leibniz’ theory of ideas 163 Ideas – realism or nominalism? 166 Ideas as dispositions 170 Ideas as objects 178 God and human ideas 182 Ideas in the mind of God 187 Possible creatures and sin 195 God and creatures: analogy and disanalogy 209 Logical and causal dependence 211 Conclusion 214 5 Concepts and definitions in Leibniz 216 Concepts, ideas, and possibilities 216 Concepts and the predicate-in-notion principle 223 Concepts and definitions 228 Concepts and essences 238 Essences and individuals 247 Actual and possible existence 249 Concepts and relations 273 ii 6 Perception, cognition, and intentionality in Leibniz 281 Direct and indirect objects 281 Representation 292 Causation 309 Sensation and cognition 317 The objects of sensation and cognition 335 Conclusion 343 Bibliography 348 iii Summary In this thesis, I consider Leibniz’ views on intentionality, and their relation to his metaphysics and particularly his views on relations. I focus in particular on how Leibniz’ theory can be understood in the light of his scholastic influences. I argue that the scholastic philosophers developed a “package” of metaphysical claims which underlay a common approach to intentionality. These claims were that relations have reality outside the mind; that God’s ideas function as exemplars of their objects; and that the mind abstracts “intelligible species” from the objects of perception. These views allowed them to defend the intuition that a thought of X is linked to X in some way by the relations of both similarity and causation. In the bulk of the thesis, I argue that Leibniz held views that were structurally similar to the “package”, which allowed him to hold a similar approach to intentionality. He believed relations to have extra-mental reality; he identified God’s ideas with possible objects; and he thought of “concepts” in ways analogous (at some points) to the scholastic “species”. For Leibniz, to think of or perceive an object is for the mind to take on a state that is structurally similar to that object. Moreover, there is a (quasi-) causal chain between a state of mind and the external object of that state of mind, and this holds even if the object is not actual, because it still exists as a possibility in the divine mind. As a result, like the scholastics, Leibniz can point to the relations of similarity and causation as playing a key role in intentionality, and he can explain how they come about. 1 1 - Introduction I am not surprised, Monsieur, that you make it known that this chapter gave you more trouble than any other in the Critique. You describe the reflections which are made there as embarrassing . You are right, Monsieur, it is an embarrassment for Dogmatists, and I am convinced that a great gehenna is inflicted upon them when they are obliged to explain the rapport that our ideas have with the things that they represent... Nevertheless, instead of casting sure light upon the difficulties in which they have become caught up, they throw powder in our eyes, and hide themselves in darker shadows than the School had ever been able to endure. 1 In this thesis, I consider Leibniz’ views on intentionality, and their relation to his metaphysics and particularly his views on relations. I focus in particular on how Leibniz’ theory can be understood in the light of his scholastic influences. In modern analytic philosophy, discussion of the problem of intentionality is typically dominated by Franz Brentano and his pioneering analysis of the problem in the mid-nineteenth century. Indeed, such is the sway that Brentano holds over this subject, that even historical surveys of pre-nineteenth-century theories of intentionality often begin with Brentano’s famous summary of the issue for which he coined the term “intentionality”: Every mental phenomenon is characterized by what the Scholastics of the Middle Ages called the intentional (or mental) inexistence of an object, and what we might call, though not wholly unambiguously, reference to a content, direction toward an object (which is not to be understood 1 Foucher (1679) F 33-34 2 here as meaning a thing), or immanent objectivity. Every mental phenomenon includes something as object within itself... 2 Yet, as that very passage indicates, Brentano himself regarded his formulation of the problem as a traditional one: the issue of intentionality was, for him, something that had already been discussed at length by the scholastics. Brentano brought intentionality to the attention of philosophers with a new forcefulness, but philosophers had not only been discussing it for centuries already – they had been well aware that it was a problem , possibly even a critical or central one for any epistemological theory. As my opening quotation from Foucher indicates, this was particularly so in the second half of the seventeenth century. In the wake of Descartes’ demolition of scholastic epistemology, there was no longer any agreed explanation of how mental phenomena could be “of” external objects; and for some philosophers, such an explanation was no longer even a theoretical possibility. The fact that Leibniz had much to say on this topic is thus of considerable interest from the point of view of the history of philosophy. If this was such a burning problem of the time, what did Leibniz – who perhaps had a broader range of interests than anyone else in his day, and who had something pertinent to say about everything – think of the matter? This question has, to date, been largely unanswered in the secondary literature. To investigate Leibniz’ views on intentionality is thus, in itself, to make an important contribution to our 2 Brentano (1973) 88 3 understanding of his philosophy. And it is also to shed light on our understanding of a key debate in the late seventeenth and early eighteenth century: the debate over whether a viable theory of intentionality was possible at all . But there is a second reason for investigating Leibniz’ views on intentionality, which is that they lie at the heart of much of his philosophy. In the chapters which follow, I shall argue that Leibniz’ views of intentionality are closely bound up with key elements of his metaphysics and epistemology – especially his understanding of relations, his commitment to the explanatory power of theism and the role of the divine ideas, and his understanding of “concepts”. As Leibniz himself might have said, each of these aspects of his thought mirrors each of the others: they stand or fall together. So although our main interest is Leibniz’ view of intentionality, the argument of this thesis touches upon many of the familiar elements of his philosophy, such as the predicate-in-notion principle, the claim that all truths about an individual can be derived a priori from its concept, the dispositional theory of ideas, the theory of perception as expression, and others. In the course of the argument, I defend a number of original interpretations of Leibniz’ texts on these subjects, which help to shed light upon his thought as a whole, not simply his views of intentionality. Indeed, it does not take much reflection to realise that intentionality is an important matter for a philosopher who believes that reality is fundamentally made up of mind-like substances, whose sole activity is to perceive. For example, 4 Look has commented on the importance in Leibniz’ metaphysics, particularly his account of the relation between mind and body, of the notion that one monad can “dominate” others. My body “contains” an infinite number of monads, but only one of them is my mind – it is the one that “dominates” all the others. Because the only things that monads actually do is perceive, Look notes 3 that dominance must involve monads perceiving each other, and that to understand what this means we must understand what it means for one monad to be the “object” of another monad’s perceptions. Dominance is thus an intentional matter. Indeed, Look also recognises that this question is closely bound up with relations. 4 He interprets Leibniz as denying the extra-mental reality of relations, which means that the relation of dominance must boil down to non-relational properties of the monads in question. As I shall argue, however, not only did Leibniz not hold such a view of relations at all, but his understanding of intentionality is fundamentally relational, in the sense that it presupposes the extra-mental reality of relations on a number of points. Dominance may therefore not pose quite the problem that Look suggests. Carlin, meanwhile, has drawn attention to the importance of final causes in Leibniz’ metaphysics. But as he argues, final causation is (for Leibniz) an intentional matter: 3 Look (2002) 386 4 Look (2002) 384-85, 389 5 ...final causation, Leibniz will maintain, is a distinctively intentional affair. The intentional character of final causation is not difficult to make out: an agent who acts intentionally acts for the sake of actualizing some state of affairs that she represents to herself. 5 Since Carlin also notes that “there are many senses in which we might say that final causes have primacy for Leibniz”, 6 it is clearly crucial to understand how Leibniz conceives of intentionality if we are to understand how he conceives of causation.