•  137
    Intentional identity revisited
    Nordic Journal of Philosophical Logic 6 (2): 147-188. 2010.
    The problem of intentional identity, as originally offered by Peter Geach, says that there can be an anaphoric link between an indefinite term and a pronoun across a sentential boundary and across propositional attitude contexts, where the actual existence of an individual for the indefinite term is not presupposed. In this paper, a semantic resolution to this elusive puzzle is suggested, based on a new quantified intensional logic and game-theoretic semantics (GTS) of imperfect information. Thi…Read more
  •  48
  •  47
    Assertive graphs
    Journal of Applied Non-Classical Logics 28 (1): 72-91. 2018.
    Peirce and Frege both distinguished between the propositional content of an assertion and the assertion of a propositional content, but with different notational means. We present a modification of Peirce’s graphical method of logic that can be used to reason about assertions in a manner similar to Peirce’s original method. We propose a new system of Assertive Graphs, which unlike the tradition that follows Frege involves no ad hoc sign of assertion. We show that axioms of intuitionistic logic c…Read more
  •  45
    Philosophical Logic (review)
    Review of Metaphysics 54 (2): 458-458. 2000.
    This book contains three Henriette Hertz Lectures delivered as the annual Philosophical Lectures for the British Academy, covering three genres of philosophical logic. In the first paper, James Higginbotham explores arguments for and against second- and higher-order logic as taken to be motivated by the properties of natural language. R. M. Sainsbury investigates the consequences of treating constraints on reporting speech as guides to meaning, with special reference to indexicals in natural lan…Read more
  •  41
    Gödel Meets Einstein: Time Travel in the Gödel Universe (review)
    Review of Metaphysics 55 (1): 170-172. 2001.
    “Intuitive time,” Gödel says, “is what everyone understood by time before relativity theory.” Such an understanding includes the perception or experience of objective lapse of time, presupposing a layer of successive “nows,” and a change in the existing. The notion of temporality that Gödel came up with in his work on the general theory of relativity has, in contrast, often been taken to demonstrate the impossibility of such a theory to account for the intuitive notion of time, and even be incon…Read more
  •  26
    Partiality and games: propositional logic
    with G. Sandu
    Logic Journal of the IGPL 9 (1): 101-121. 2001.
    We study partiality in propositional logics containing formulas with either undefined or over-defined truth-values. Undefined values are created by adding a four-place connective W termed transjunction to complete models which, together with the usual Boolean connectives is shown to be functionally complete for all partial functions. Transjunction is seen to be motivated from a game-theoretic perspective, emerging from a two-stage extensive form semantic game of imperfect information between two…Read more
  •  23
    Review of J. Hintikka, Language, Truth and Logic in Mathematics (review)
    Journal of Logic, Language and Information 8 (1): 121-124. 1999.
  •  22
    Games in philosophical logic
    Nordic Journal of Philosophical Logic 4 143-174. 1999.
  •  13
    Paul John King, kiril Ivanov Simov, and bjørn Aldag
    with Alexander Franz, Carson T. Schütze, and Jaakko Hintikka
    Journal of Logic, Language, and Information 8 487-489. 1999.
  • Usko (edited book)
    with Pihlström Sami and Pilvi Toppinen
    Juvenes Print. 2009.
  • On Peirce's late proof of pragmaticism
    with Lauri Snellman
    Acta Philosophica Fennica 78 275. 2006.