The aim of this book is to present essays centered upon the subjects of Formal Ontology and Logical Philosophy. The idea of investigating philosophical problems by means of logical methods was intensively promoted in Torun by the Department of Logic of Nicolaus Copernicus University during last decade. Another aim of this book is to present to the philosophical and logical audience the activities of the Torunian Department of Logic during this decade. The papers in this volume contain the results concerning Logic and Logical Philosophy, obtained within the confines of the projects initiated by the Department of Logic and other research projects in which the Torunian Department of Logic took part.

Structure or system is a ubiquitous and uneliminable feature of all our experience and theory, and requires an ontological analysis. The essays collected in this volume provide an account of structure founded upon the proper analysis of polyadic relations as the irreducible and defining elements of structure. It is argued that polyadic relations are ontic predicates in the insightful sense of intension-determined agent-combinators, monadic properties being the limiting and historically misleading case. This assay of ontic predicates has a number of powerful explanatory implications, including fundamentally: providing ontology with a principium individuationis, demonstrating the perennial theory that properties and relations are individuated as unit attributes or ‘instances’, giving content to the ontology of facts or states of affairs, and providing a means to precisely differentiate identity from indiscernibility. The differentiation of the unrepeatable combinatorial and repeatable intension aspects of ontic predicates makes it possible to properly diagnose and disarm the classis Bradley Regress Argument aimed against attributes and universals, an argument that trades on confusing these aspects. It is argued that these two aspects of ontic predicates form a ‘composite simple’, an explanation that sheds light on the nature and necessity of the medieval formal distinction, e.g., the distinctio formalis a parte rei of Scotus. Following from this analysis of ontic predication there is given a number of principles delineating realist instance ontology, together with a critique of both nominalistic trope theory and modern revivals of Aristotle’s instance ontology of the Categories. It is shown how the resulting theory of facts can, via ‘horizontal’ and ‘vertical’ composition, account for all the hierarchical structuring of our experience and theory, and, importantly, how this can rest upon an atomic ontic level composed of only dependent ontic predicates. The latter is a desideratum for the proposed ‘Structural Realism’ ontology for micro-physics where at its lowest level the physical is said to be totally relational/structural. Nullified is the classic and insidious assumption that dependent entities presuppose a class of independent substrata or ‘substances’, and with this any pressure to admit ‘bare particulars’ and intensionless relations or ‘ties’. The logic inherent in realist instance ontology-termed ‘PPL’-is formalized in detail and given a consistency proof. Demonstrated is the logic’s power to distinguish legitimate from illegitimate impredicative definitions, and in this how it provides a general solution to the classic self-referential paradoxes. PPL corresponds to Gödel’s programmatic ‘Theory of Concepts’. The last essay, not previously published, provides a detailed differentiation of identity from indiscernibility, preliminary to which is given an explanation of in what sense a predicate logic presupposes an ontology of predication. The principles needed for the differentiation have the significant implication (e.g., for the foundations of mathematics) of implying an infinity of logical entities, viz., instances of the identity relation.

Bob Hale presents a broadly Fregean approach to metaphysics, according to which ontology and modality are mutually dependent upon one another. He argues that facts about what kinds of things exist depend on facts about what is possible. Modal facts are fundamental, and have their basis in the essences of things—not in meanings or concepts.

This edited volume is a comprehensive presentation of views on the relations between metaphysics and logic from Aristotle through twentieth century philosophers who contributed to the return of metaphysics in the analytic tradition. The collection combines interest in logic and its history with interest in analytical metaphysics and the history of metaphysical thought. By so doing, it adds both to the historical understanding of metaphysical problems and to contemporary research in the field. Throughout the volume, essays focus on metaphysica generalis, or the systematic study of the most general categories of being. Beginning with Aristotle and his Categories , the volume goes on to trace metaphyscis and logic through the late ancient and Arabic traditions, examining the views of Thomas Aquinas, Duns Scotus, and William Ockham. Moving into the early modern period, contributors engage with Leibniz's metaphysics, Kant's critique of metaphysics, the relation between logic and ontology in Hegel, and Bolzano's views. Subsequent chapters address: Charles S. Peirce's logic and metaphysics; the relevance of set-theory to metaphysics; Meinong's theory of objects; Husserl's formal ontology; early analytic philosophy; C.I. Lewis and his relation to Russell; and the relations between Frege, Carnap, and Heidegger. Surveying metaphysics through to the contemporary age, essays explore W.V. Quine's attitude towards metaphysics; Wilfrid Sellars's relation to antidescriptivism as it connects to Kripke's; the views of Putnam and Kaplan; Peter F. Strawson's and David M. Armstrong's metaphysics; Trope theory; and its relation to Popper's conception of three worlds. The volume ends with a chapter on transcendental philosophy as ontology. In each chapter, contributors approach their topics not merely in an historical and exegetical fashion, but also engage critically with the thought of the philosophers whose work they discuss, offering synthesis and original philosophical thought in the volume, in addition to very extensive and well-informed analysis and interpretation of important philosophical texts. The volume will serve as an essential reference for scholars of metaphysics and logic.

Contemporary analytic philosophy can generally be characterized by the following tendencies: commitment to first-order predicate logic as the only viable formal logic; rejection of correspondence theories of truth; a view of existence as something expressed by the existential quantifier; a metaphysics that doesn’t give the world as a whole its due. This book seeks to offer an alternative analytic theory, one that provides a unified account of what there is, how we speak about it, the underlying logic of our language, how the truth of what we say is determined, and the central role of the real world in all of this. The result is a robust account of reality. The inspiration for many of the ideas that constitute this overall theory comes from such sources as Aristotle, Leibniz, Ryle, and Sommers.