•  522
    Unsharpenable Vagueness
    Philosophical Topics 28 (1): 1-10. 2000.
    A plausible thought about vagueness is that it involves semantic incompleteness. To say that a predicate is vague is to say (at the very least) that its extension is incompletely specified. Where there is incomplete specification of extension there is indeterminacy, an indeterminacy between various ways in which the specification of the predicate might be completed or sharpened. In this paper we show that this idea is bound to founder by presenting an argument to the effect that there are vague …Read more
  •  498
    Event Location and Vagueness
    Philosophical Studies 128 (2): 313-336. 2006.
    Most event-referring expressions are vague; it is utterly difficult, if not impossible, to specify the exact spatiotemporal location of an event from the words that we use to refer to it. We argue that in spite of certain prima facie obstacles, such vagueness can be given a purely semantic (broadly supervaluational) account
  •  24
    Sur la frontière entre ontologie matérielle et ontologie formelle
    RÉPHA, revue étudiante de philosophie analytique 3 53-61. 2011.
  • Logica, Seconda edizione
    with John Nolt and Dennis A. Rohatyn
    McGraw-Hill Italia. 2007.
    Extended revised edition of "Logica" (2003)
  •  9
    Logica
    with John Nolt and Dennis A. Rohatyn
    McGraw-Hill Italia. 2003.
    Italian translation of "Schaum's Outline of Theory and Problems of Logic" (1988)
  •  12
    Complementary Proof Nets for Classical Logic
    Logica Universalis 17 (4): 411-432. 2023.
    A complementary system for a given logic is a proof system whose theorems are exactly the formulas that are not valid according to the logic in question. This article is a contribution to the complementary proof theory of classical propositional logic. In particular, we present a complementary proof-net system, $$\textsf{CPN}$$ CPN, that is sound and complete with respect to the set of all classically invalid (one-side) sequents. We also show that cut elimination in $$\textsf{CPN}$$ CPN enjoys s…Read more
  •  149
    Thinking about space is thinking about spatial things. The table is on the carpet; hence the carpet is under the table. The vase is in the box; hence the box is not in the vase. But what does it mean for an object to be somewhere? How are objects tied to the space they occupy? This book is concerned with these and other fundamental issues in the philosophy of spatial representation. Our starting point is an analysis of the interplay between mereology (the study of part/whole relations), topology…Read more
  •  4
    Undetached Parts and Disconnected Wholes
    In Christer Svennerlind, Almäng Jan & Rögnvaldur Ingthorsson (eds.), Johanssonian Investigations: Essays in Honour of Ingvar Johansson on His Seventieth Birthday, Ontos Verlag. pp. 696-708. 2013.
  •  47
    Mereology then and now
    Logic and Logical Philosophy 24 (4). 2015.
    This paper offers a critical reconstruction of the motivations that led to the development of mereology as we know it today, along with a brief description of some problems that define current research in the field.
  •  23
    The purpose of Parts and Places, say Casati and Varzi in their introduction, is to construct “a theory of our spatial competence,” a theory that will lay bare how we conceive of space and the things that lie within it. Its purpose, then, is psychological, not metaphysical. Its object of study is not space. It is not the things that lie within it. Rather its object of study is us. In this regard, Parts and Places is at best a mixed success.
  •  445
    A philosophical dialogue on the functioning, the limits, and the paradoxes of our electoral practices, dealing with such basic questions as: What is a vote? How do we count votes? And do votes really count?
  •  429
    Topological Essentialism
    Philosophical Studies 100 (3): 217-236. 2000.
    Considering topology as an extension of mereology, this paper analyses topological variants of mereological essentialism (the thesis that an object could not have different parts than the ones it has). In particular, we examine de dicto and de re versions of two theses: (i) that an object cannot change its external connections (e.g., adjacent objects cannot be separated), and (ii) that an object cannot change its topological genus (e.g., a doughnut cannot turn into a sphere). Stronger forms of s…Read more
  •  265
    Holes are a good example of the sort of entity that down-to-earth philosophers would be inclined to expel from their ontological inventory. In this work we argue instead in favor of their existence and explore the consequences of this liberality—odd as they might appear. We examine the ontology of holes, their geometry, their part-whole relations, their identity and their causal role, the ways we perceive them. We distinguish three basic kinds of holes: blind hollows, perforating tunnels, and in…Read more
  •  372
    Foreword to ''Lesser Kinds''
    The Monist 90 (3): 331-332. 2007.
    This issue of The Monist is devoted to the metaphysics of lesser kinds, which is to say those kinds of entity that are not generally recognized as occupying a prominent position in the categorial structure of the world. Why bother? We offer two sorts of reason. The first is methodological. In mathematics, it is common practice to study certain functions (for instance) by considering limit cases: What if x = 0? What if x is larger than any assigned value? Physics, too, often studies the (idealize…Read more
  •  165
    Ontological commitment and reconstructivism
    Erkenntnis 55 (1): 33-50. 2001.
    Some forms of analytic reconstructivism take natural language (and common sense at large) to be ontologically opaque: ordinary sentences must be suitably rewritten or paraphrased before questions of ontological commitment may be raised. Other forms of reconstructivism take the commitment of ordinary language at face value, but regard it as metaphysically misleading: common-sense objects exist, but they are not what we normally think they are. This paper is an attempt to clarify and critically as…Read more
  •  4
    Book Reviews (review)
    with Rainer Bäuerle, N. C. A. Da Costa, O. Bueno, Javier De Lorenzo, Alberto Zanardo, Alan R. Perreiah, K. Misiuna, H. Sinaceur, T. Hailperin, S. Bringsjord, T. Wiliamson, and Barry Smith
    History and Philosophy of Logic 17 (1-2): 155-177. 1996.
    Gennaro Chtjerchia, Dynamics of meaning: anaphora, presupposition, and the the of grammar. Chicago and London: The University of Chicago Press, 1995.xv+ 270 pp, £59.95, £31.95 G. Pr...
  •  28
    Intuitionistic Mereology II: Overlap and Disjointness
    Journal of Philosophical Logic 52 (4): 1197-1233. 2023.
    This paper extends the axiomatic treatment of intuitionistic mereology introduced in Maffezioli and Varzi (_Synthese, 198_(S18), 4277–4302 2021 ) by examining the behavior of constructive notions of overlap and disjointness. We consider both (i) various ways of defining such notions in terms of other intuitionistic mereological primitives, and (ii) the possibility of treating them as mereological primitives of their own.
  •  49
    On Three Axiom Systems for Classical Mereology
    Logic and Logical Philosophy 28 (2). 2019.
    Paul Hovda’s excellent paper ‘What Is Classical Mereology?' has fruitfully reshaped the debate concerning the axiomatic foundations of classical mereology. Precisely because of the importance of Hovda’s work and its usefulness as a reference tool, we note here that one of the five axiom systems presented therein, corresponding the ‘Third Way’ to classical mereology, is defective and must be amended. In addition, we note that two other axiom systems, corresponding to the ‘First Way’ and to the ‘F…Read more
  •  108
    Atoms, Gunk, and the Limits of ‘Composition’
    Erkenntnis 81 (2): 231-235. 2016.
    It is customary practice to define ‘x is composed of the ys’ as ‘x is a sum of the ys and the ys are pairwise disjoint ’. This predicate has played a central role in the debate on the special composition question and on related metaphysical issues concerning the mereological structure of objects. In this note we show that the customary characterization is nonetheless inadequate. We do so by constructing a mereological model where everything qualifies as composed of atoms even though some element…Read more
  •  484
    The niche
    Noûs 33 (2): 214-238. 1999.
    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 will be illustrated above all by means of simple biolo…Read more
  • Vagueness, logic and ontology
    In Darragh Byrne & Max Kölbel (eds.), Arguing about language, Routledge. 2010.
  •  130
    On Perceiving Abs nces
    Gestalt Theory 44 (3): 213-242. 2022.
    Can we really perceive absences, i.e., missing things? Sartre tells us that when he arrived late for his appointment at the café, he saw the absence of his friend Pierre. Is that really what he saw? Where was it, exactly? Why didn’t Sartre see the absence of other people who were not there? Why did other people who were there not see the absence of Pierre? The perception of absences gives rise to a host of conundrums and is constantly on the verge of conceptual confusion. Here I focus on the nee…Read more
  •  485
    The Structure of Spatial Localization
    Philosophical Studies 82 (2). 1996.
    What are the relationships between an entity and the space at which it is located? And between a region of space and the events that take place there? What is the metaphysical structure of localization? What its modal status? This paper addresses some of these questions in an attempt to work out at least the main coordinates of the logical structure of localization. Our task is mostly taxonomic. But we also highlight some of the underlying structural features and we single out the interactions b…Read more
  •  2
    Complementary Logics for Classical Propositional Languages
    Kriterion - Journal of Philosophy 1 (4): 20-24. 1992.
  •  16
    Schaum's Outline of Logic
    with John Eric Nolt and Dennis Rohatyn
    Mcgraw Hill. 1988.
    An outline of the material covered in courses on Formal and Informal Logic. The outline includes chapters on mathematical approaches to logic as well as on fallacies, deduction and induction, probability, and other major topics. Logic is traditionally taught by means of problem solving exercises, so the subject is well suited to a Schaum's Outline approach.
  •  10
    Events
    Dartmouth. 1996.
    Philosophical questions about events lie at the crossing of several disciplines, from metaphysics and logic to philosophy of language, action theory, the philosophy of space and time.
  • Italian translation of "Holes and Other Superficialities" (1994)
  •  8
    Ontologie
    Ithaque. 2010.
    French translation of "Ontologia" (2005)