•  768
    Imagine the possibilities: information without overload
    Logique Et Analyse 49 (196). 2006.
    Information is often modelled as a set of relevant possibilities, treated as logically possible worlds. However, this has the unintuitive consequence that the logical consequences of an agent's information cannot be informative for that agent. There are many scenarios in which such consequences are clearly informative for the agent in question. Attempts to weaken the logic underlying each possible world are misguided. Instead, I provide a genuinely psychological notion of epistemic possibility a…Read more
  •  47
    Book reviews (review)
    Studia Logica 87 (2-3): 359-362. 2007.
  •  44
    Verifying Space and Time Requirements for Resource-Bounded Agents
    with Natasha Alechina, Piergiorgio Bertoli, Chiara Ghidini, Brian Logan, and Luciano Serafini
    In A. Lomuscio & S. Edelkamp (eds.), Model Checking and Artificial Intelligence, Springer. 2007.
    The effective reasoning capability of an agent can be defined as its capability to infer, within a given space and time bound, facts that are logical consequences of its knowledge base. In this paper we show how to determine the effective reasoning capability of an agent with limited memory by encoding the agent as a transition system and automatically verifying whether a state where the agent believes a certain conclusion is reachable from the start state. We present experimental results using …Read more
  •  640
    Divers (2014) presents a set of de re modal truths which, he claims, are inconvenient for Lewisean modal realism. We argue that there is no inconvenience for Lewis.
  •  1072
    The Conjunction and Disjunction Theses
    Mind 118 (470): 411-415. 2009.
    Rodriguez-Pereyra (2006) argues for the disjunction thesis but against the conjunction thesis. I argue that accepting the disjunction thesis undermines his argument against the conjunction thesis.
  •  625
    Hintikka and Cresswell on Logical Omniscience
    Logic and Logical Philosophy 15 (3): 325-354. 2006.
    I discuss three ways of responding to the logical omniscience problems faced by traditional ‘possible worlds’ epistemic logics. Two of these responses were put forward by Hintikka and the third by Cresswell; all three have been influential in the literature on epistemic logic. I show that both of Hintikka's responses fail and present some problems for Cresswell’s. Although Cresswell's approach can be amended to avoid certain unpalatable consequences, the resulting formal framework collapses to a…Read more
  •  1223
    Against Yagisawa's modal realism
    Analysis 73 (1): 10-17. 2013.
    In his book Worlds and Individuals, Possible and Otherwise (2010), Takashi Yagisawa presents and argues for a novel and imaginative version of modal realism. It differs both from Lewis’s modal realism (Lewis 1986) and from actualists’ ersatz accounts (Adams 1974; Sider 2002). In this paper, I’ll present two arguments, each of which shows that Yagisawa’s metaphysics is incoherent. The first argument shows that the combination of Yagisawa’s metaphysics with impossibilia leads to triviality: every …Read more
  •  1247
    The Problem with Truthmaker-Gap Epistemicism
    Thought: A Journal of Philosophy 1 (4): 320-329. 2012.
    Epistemicism about vagueness is the view that vagueness, or indeterminacy, is an epistemic matter. Truthmaker-gap epistemicism is the view that indeterminate truths are indeterminate because their truth is not grounded by any worldly fact. Both epistemicism in general and truthmaker-gap epistemicism originated in Roy Sorensen's work on vagueness. My aim in this paper is to give a characterization of truthmaker-gap epistemicism and argue that the view is incompatible with higher-order vagueness: …Read more
  •  155
    The Accidental Properties of Numbers and Properties
    Thought: A Journal of Philosophy 1 (2): 134-140. 2012.
    According to genuine modal realism, some things (including numbers and properties) lack distinct counterparts in different worlds. So how can they possess any of their properties contingently? Egan (2004) argues that to explain such accidental property possession, the genuine modal realist must depart from Lewis and identify properties with functions, rather than with sets of possibilia. We disagree. The genuine modal realist already has the resources to handle Egan's proposed counterexamples. A…Read more