Stefano Di Bella

The chapter considers the presence of nominalist motives in the development of Leibniz’s logical and ontological thought. The discussion begins with Leibniz’s Preface to his reedition of the work of the Renaissance nominalist Nizolius, and emphasizes Leibniz’s acceptance of antirealistic assumptions, his balancing of them with Platonic elements, and his rejection of Hobbes’s conventionalist implications. There is also a consideration of the deflationary treatment of abstract terms that Leibniz offers as part of his program of providing ontological clarification by way of semantic analysis. Leibniz applies an analysis of abstract talk stemming from Hobbes, with the aim of availing himself of the resources of certain expressive devices in logical and scientific language, while avoiding realistic commitments. Leibniz’s final profession of a “precautionary nominalism” confirms his preference for ontological economy, but also leaves unresolved some problems in his “austere” account of the ontology of predication and change.

The ancient topic of universals was central to scholastic philosophy, which raised the question of whether universals exist as Platonic forms, as instantiated Aristotelian forms, as concepts abstracted from singular things, or as words that have universal signification. It might be thought that this question lost its importance after the decline of scholasticism in the modern period. However, the fourteen contributions to this volume indicate that the issue of universals retained its vitality in modern philosophy. Modern philosophers in fact were interested in three sets of issues concerning universals: (1) issues concerning the ontological status of universals, (2) issues concerning the psychology of the formation of universal concepts or terms, and (3) issues concerning the value and use of universal concepts or terms in the acquisition of knowledge. Chapters in this volume consider the various forms of “Platonism,” “conceptualism,” and “nominalism” (and distinctive combinations thereof) that emerged from the consideration of such issues in the work of modern philosophers. The volume covers not only the canonical modern figures, namely, Descartes, Spinoza, Leibniz, Locke, Berkeley, Hume, and Kant, but also more neglected figures such as Pierre Gassendi, Pierre-Sylvain Regis, Nicolas Malebranche, Henry More, Ralph Cudworth, and John Norris.

The aim of this paper is to trace in Leibniz’s drafts the sketched outline of a conceptual framework he organized around the key concept of ‘requisite’. We are faced with the project of a semi-formal theory of conditions, whose logical skeleton can have a lot of different interpretations. In particular, it is well suited to capture some crucial relations of ontological dependence. Firstly the area of ‘mediate requisites’ is explored - where causal and temporal relations are dealt with on the basis of a general theory of ‘consequence’.Then the study of ‘immediate requisites’ is taken into account - a true sample of mereological inquiry, where Leibniz strives for a unitary treatment of part-whole relation, conceptual inclusion and inherence. Far from simply conflating these relations one with another and with causality, therefore, Leibniz tried to spell them out, while at the same time understanding them within a single conceptual framework.

Leibniz's treatment of the concept of res should be considered in the context of his semantic-ontological reflections on the relationship of language, thought and reality, profoundly shaped by a nominalistically minded deflationary approach. In this paper I consider (a) the role of res as a kind of super-category and its relationship with ens; then I pass to consider the narrower usage of res to designate a concrete item, in the sense (b) of a subject of inherence as opposed to properties, and (c) of an object as opposed to a concept.

“Baroque” sensitivity - a concept elusive enough - develops in the complex post-Renaissance culture and largely co-exists with the new culture shaped by seventeenth-century scientific revolution. In Leibniz’s experience a totally “modern” exploration of the new world mixes with the adoption of rhetorical tools and spiritual attitudes typical of baroque culture. I present here some samples of this Leibnizian approch, where some central themes of the new science and new philosophy (mechanism, representation, the issue of the sense of reality) are reinterpreted within an original practice of re-enchanting and theatralizing of world.

The 1648 exchange between Descartes and Arnauld focuses on several distinct but intertwined topics concerning Descartes’s philosophy of mind. Descartes’s acknowledgment of thinking as the essence of the mind implied a strong ‘actualist’ view of this essential activity. Arnauld’s objcetions reveal the problematic implications of this ontology of mind, from the role of memory and the temporal nature of our thought to the radical challenge of giving the status of an essence to such a temporal activity.

In his well-known Discourse on Metaphysics, Leibniz puts individual substance at the basis of metaphysical building. In so doing, he connects himself to a venerable tradition. His theory of individual concept, however, breaks with another idea of the same tradition, that no account of the individual as such can be given. Contrary to what has been commonly accepted, Leibniz’s intuitions are not the mere result of the transcription of subject-predicate logic, nor of the uncritical persistence of some old metaphysical assumptions. They grow, instead, from an unprejudiced inquiry about our basic ontological framework, where logic of truth, linguistic analysis, and phenomenological experience of the mind’s life are tightly interwoven. Leibniz’s struggle for a concept capable of grasping concrete individuals as such is pursued in an age of great paradigm changes – from the Scholastic background to Hobbes’s nominalism to the Cartesian ‘way of ideas’ or Spinoza’s substance metaphysics – when the relationships among words, ideas and things are intensively discussed and wholly reshaped. This is the context where the genesis and significance of Leibniz’s theory of ‘complete being’ and its concept are reconstrued. The result is a fresh look at some of the most perplexing issues in Leibniz scholarship, like his ideas about individual identity and the thesis that all its properties are essential to an individual. The questions Leibniz faces, and to which his theory of individual substance aims to answer, are yet, to a large extent, those of contemporary metaphysics: how to trace a categorial framework? How to distinguish concrete and abstract items? What is the metaphysical basis of linguistic predication? How is trans-temporal sameness assured? How to make sense of essential attributions? In this ontological framework Leibniz’s further questions about the destiny of human individuals and their history are spelt out. Maybe his answers also have something to tell us. This book is aimed at all who are interested in Leibniz’s philosophy, history of early modern philosophy and metaphysical issues in their historical development.