•  229
    Simple Hyperintensional Belief Revision
    Erkenntnis 84 (3): 559-575. 2018.
    I present a possible worlds semantics for a hyperintensional belief revision operator, which reduces the logical idealization of cognitive agents affecting similar operators in doxastic and epistemic logics, as well as in standard AGM belief revision theory. belief states are not closed under classical logical consequence; revising by inconsistent information does not perforce lead to trivialization; and revision can be subject to ‘framing effects’: logically or necessarily equivalent contents c…Read more
  •  39
    The Fundamental Problem of Logical Omniscience
    Journal of Philosophical Logic 1-40. forthcoming.
    We propose a solution to the problem of logical omniscience in what we take to be its fundamental version: as concerning arbitrary agents and the knowledge attitude per se. Our logic of knowledge is a spin-off from a general theory of thick content, whereby the content of a sentence has two components: an intension, taking care of truth conditions; and a topic, taking care of subject matter. We present a list of plausible logical validities and invalidities for the logic of knowledge per se for …Read more
  •  369
    Negation on the Australian Plan
    with Greg Restall
    Journal of Philosophical Logic 48 (6): 1119-1144. 2019.
    We present and defend the Australian Plan semantics for negation. This is a comprehensive account, suitable for a variety of different logics. It is based on two ideas. The first is that negation is an exclusion-expressing device: we utter negations to express incompatibilities. The second is that, because incompatibility is modal, negation is a modal operator as well. It can, then, be modelled as a quantifier over points in frames, restricted by accessibility relations representing compatibilit…Read more
  •  63
    Impossible Worlds
    with Mark Jago
    Oxford University Press. 2019.
    We need to understand the impossible. Francesco Berto and Mark Jago start by considering what the concepts of meaning, information, knowledge, belief, fiction, conditionality, and counterfactual supposition have in common. They are all concepts which divide the world up more finely than logic does. Logically equivalent sentences may carry different meanings and information and may differ in how they're believed. Fictions can be inconsistent yet meaningful. We can suppose impossible things withou…Read more
  •  73
    The Logic of Fast and Slow Thinking
    with Anthia Solaki and Sonja Smets
    Erkenntnis 1-30. forthcoming.
    We present a framework for epistemic logic, modeling the logical aspects of System 1 and System 2 cognitive processes, as per dual process theories of reasoning. The framework combines non-normal worlds semantics with the techniques of Dynamic Epistemic Logic. It models non-logically-omniscient, but moderately rational agents: their System 1 makes fast sense of incoming information by integrating it on the basis of their background knowledge and beliefs. Their System 2 allows them to slowly, ste…Read more
  •  359
    Truth in Fiction, Impossible Worlds, and Belief Revision
    Australasian Journal of Philosophy 97 (1): 178-193. 2019.
    We present a theory of truth in fiction that improves on Lewis's [1978] ‘Analysis 2’ in two ways. First, we expand Lewis's possible worlds apparatus by adding non-normal or impossible worlds. Second, we model truth in fiction as belief revision via ideas from dynamic epistemic logic. We explain the major objections raised against Lewis's original view and show that our theory overcomes them.
  •  30
    I would like to attack a certain view: The view that the concept of identity can fail to apply to some things although, for some positive integer n, we have n of them. The idea of entities without self-identity is seriously entertained in the philosophy of quantum mechanics. It is so pervasive that it has been labelled the Received View. I introduce the Received View in Section 1. In Section 2 I explain what I mean by entity, and I argue that supporters of the Received View should agree with my …Read more
  •  63
    This research is published within the project ‘The Logic of Conceivability’, funded by the European Research Council, Grant Number 681404.
  •  304
    We present a formal semantics for epistemic logic, capturing the notion of knowability relative to information (KRI). Like Dretske, we move from the platitude that what an agent can know depends on her (empirical) information. We treat operators of the form K_AB (‘B is knowable on the basis of information A’) as variably strict quantifiers over worlds with a topic- or aboutness- preservation constraint. Variable strictness models the non-monotonicity of knowledge acquisition while allowing knowl…Read more
  •  781
    Aboutness in Imagination
    Philosophical Studies 175 (8): 1871-1886. 2018.
    I present a formal theory of the logic and aboutness of imagination. Aboutness is understood as the relation between meaningful items and what they concern, as per Yablo and Fine’s works on the notion. Imagination is understood as per Chalmers’ positive conceivability: the intentional state of a subject who conceives that p by imagining a situation—a configuration of objects and properties—verifying p. So far aboutness theory has been developed mainly for linguistic representation, but it is nat…Read more
  •  15
    Modal Meinongianism and Actuality
    Humana Mente 6 (25). 2013.
    Modal Meinongianism is the most recent neo-Meinongian theory. Its main innovation consists in a Comprehension Principle which, unlike other neo-Meinongian approaches, seemingly avoids limitations on the properties that can characterize objects. However, in a recent paper A. Sauchelli has raised an objection against modal Meinongianism, to the effect that properties and relations involving reference to worlds at which they are instantiated, and specifically to the actual world or parts thereof, f…Read more
  •  23
    Un'interpretazione analitica della dialettica hegeliana
    Iride: Filosofia e Discussione Pubblica 17 (3): 569-592. 2004.
  •  14
    Modus Tollerns. Kant, Hegel e la critica della nozione logica di sostanza
    Giornale di Metafisica 25 (2): 287-304. 2003.
  • Quale barba per il rasoio di ockham?: Problemi del riduzionismo metafisico
    with Enrico Bellinelli
    Divus Thomas 110 (2): 9-28. 2007.
  • Dialettica come semantica
    Epistemologia 26 (1): 5-44. 2003.
  •  198
    Williamson on Counterpossibles
    Journal of Philosophical Logic 47 (4): 693-713. 2018.
    A counterpossible conditional is a counterfactual with an impossible antecedent. Common sense delivers the view that some such conditionals are true, and some are false. In recent publications, Timothy Williamson has defended the view that all are true. In this paper we defend the common sense view against Williamson’s objections.
  •  43
    Guest editors' introduction
    with Koji Tanaka, Edwin Mares, and Francesco Paoli
    Logic and Logical Philosophy 19 (1-2): 5-6. 2010.
    A logic is said to be paraconsistent if it doesn’t license you to infer everything from a contradiction. To be precise, let |= be a relation of logical consequence. We call |= explosive if it validates the inference rule: {A,¬A} |= B for every A and B. Classical logic and most other standard logics, including intuitionist logic, are explosive. Instead of licensing you to infer everything from a contradiction, paraconsistent logic allows you to sensibly deal with the contradiction
  • Scenari dell’impossibile. La contraddizione nel pensiero contemporaneo (edited book)
    with Francesco Altea
    Il Poligrafo. 2007.
  •  232
    The Firmest of All Principles
    In Channa van Dijk, Eva van der Graaf, Michiel den Haan, Rosa de Jong, Christiaan Roodenburgh, Dyane Til & Deva Waal (eds.), Under Influence - Philosophical Festival Drift (2014), . pp. 82-93. 2015.
  •  705
    Absolute Contradiction, Dialetheism, and Revenge
    Review of Symbolic Logic 7 (2): 193-207. 2014.
    Is there a notion of contradiction—let us call it, for dramatic effect, “absolute”—making all contradictions, so understood, unacceptable also for dialetheists? It is argued in this paper that there is, and that spelling it out brings some theoretical benefits. First it gives us a foothold on undisputed ground in the methodologically difficult debate on dialetheism. Second, we can use it to express, without begging questions, the disagreement between dialetheists and their rivals on the nature o…Read more
  •  189
    Modal Meinongianism for Fictional Objects
    Metaphysica 9 (2): 205-218. 2008.
    Drawing on different suggestions from the literature, we outline a unified metaphysical framework, labeled as Modal Meinongian Metaphysics (MMM), combining Meinongian themes with a non-standard modal ontology. The MMM approach is based on (1) a comprehension principle (CP) for objects in unrestricted, but qualified form, and (2) the employment of an ontology of impossible worlds, besides possible ones. In §§1–2, we introduce the classical Meinongian metaphysics and consider two famous Russellia…Read more
  •  608
    In his famous work on vagueness, Russell named “fallacy of verbalism” the fallacy that consists in mistaking the properties of words for the properties of things. In this paper, I examine two (clusters of) mainstream paraconsistent logical theories – the non-adjunctive and relevant approaches –, and show that, if they are given a strongly paraconsistent or dialetheic reading, the charge of committing the Russellian Fallacy can be raised against them in a sophisticated way, by appealing to the in…Read more
  •  118
    Cellular automata
    with Jacopo Tagliabue
    Stanford Encyclopedia of Philosophy -. 2012.
    Cellular automata (henceforth: CA) are discrete, abstract computational systems that have proved useful both as general models of complexity and as more specific representations of non-linear dynamics in a variety of scientific fields. Firstly, CA are (typically) spatially and temporally discrete: they are composed of a finite or denumerable set of homogeneous, simple units, the atoms or cells. At each time unit, the cells instantiate one of a finite set of states. They evolve in parallel at dis…Read more
  •  497
    The world is either digital or analogue
    with Jacopo Tagliabue
    Synthese 191 (3): 481-497. 2014.
    We address an argument by Floridi (Synthese 168(1):151–178, 2009; 2011a), to the effect that digital and analogue are not features of reality, only of modes of presentation of reality. One can therefore have an informational ontology, like Floridi’s Informational Structural Realism, without commitment to a supposedly digital or analogue world. After introducing the topic in Sect. 1, in Sect. 2 we explain what the proposition expressed by the title of our paper means. In Sect. 3, we describe Flor…Read more
  •  324
    Non-Normal Worlds and Representation
    In Michal Peliš & Vít Punčochář (eds.), The Logica Yearbook, College Publications. 2012.
    World semantics for relevant logics include so-called non-normal or impossible worlds providing model-theoretic counterexamples to such irrelevant entailments as (A ∧ ¬A) → B, A → (B∨¬B), or A → (B → B). Some well-known views interpret non-normal worlds as information states. If so, they can plausibly model our ability of conceiving or representing logical impossibilities. The phenomenon is explored by combining a formal setting with philosophical discussion. I take Priest’s basic relevant logic…Read more