Achille C. Varzi

Hans Herzberger, now retired and Emeritus Professor of Philosophy at the University of Toronto, had a major influence on a generation of philosophers. In his honor and in appreciation of his impressive scholarship and personal influence, this volume presents essays from philosophers such as Isaac Levi, Calvin Normore, Jamie Tappenden, Alasdair Urquhart, Achille Varzi, and Steven Yablo. Each essay is original and appears here for the first time. They are fresh, illuminating, and cover an eclectic range of topics, including rational choice theory, Frege scholarship and interpretation, the nature of truth, the inexpressible and the unknowable, and fundamental ontology – all topics of central importance in philosophy and all dear to the heart of Hans Herzberger.

The concept of niche (setting, context, habitat, environment) has been little studied by ontologists, in spite of its wide application in a variety of disciplines from evolutionary biology to economics. What follows is a first formal theory of this concept, a theory of the relations between objects and their niches. The theory builds upon existing work on mereology, topology, and the theory of spatial location as tools of formal ontology. It is illustrated above all by means of simple biological examples, but the concept of niche should be understood as being, like concepts such as part, boundary, and location, a structural concept that is applicable in principle to a wide range of different domains.

Classically, truth and falsehood are opposite, and so are logical truth and logical falsehood. In this paper we imagine a situation in which the opposition is so pervasive in the language we use as to threaten the very possibility of telling truth from falsehood. The example exploits a suggestion of Ramsey’s to the effect that negation can be expressed simply by writing the negated sentence upside down. The difference between ‘p’ and ‘~~p’ disappears, the principle of double negation becomes trivial, and the truth/falsehood opposition is up for grabs. Our moral is that this indeterminacy undermines the idea of inferential role semantics.

Just as ontology developed over the centuries as part of philosophy, so in recent years ontology has become intertwined with the development of the information sciences. Researchers in various fields have come to realize that a solid foundation for their projects calls for an explicit theorization of the types of entities and relations that make up their respective domains of inquiry, and as the need for integrating such projects arises, so does the need to identify common ontological principles over ad hoc, case-based solutions. This volume collects the papers presented at the third international conference devoted to current research in this area, including invited papers by P. Gärdenfors and A. L. Thomasson.

There are two ways of understanding the notion of a contradiction: as a conjunction of a statement and its negation, or as a pair of statements one of which is the negation of the other. Correspondingly, there are two ways of understanding the Law of Non-Contradiction (LNC), i.e., the law that says that no contradictions can be true. In this paper I offer some arguments to the effect that on the first (collective) reading LNC is non-negotiable, but on the second (distributive) reading it is perfectly plausible to suppose that LNC may, in some rather special and perhaps undesirable circumstances, fail to hold.