•  30
    How to be absolutely fair Part I: The Fairness formula
    Economics and Philosophy. forthcoming.
    We present the first comprehensive theory of fairness that conceives of fairness as having two dimensions: a comparative and an absolute one. The comparative dimension of fairness has traditionally been the main interest of Broomean fairness theories. It has been analysed as satisfying competing individual claims in proportion to their respective strengths. And yet, many key contributors to Broomean fairness agree that ‘absolute’ fairness is important as well. We make this concern precise by int…Read more
  •  13
    In the article ‘How to be absolutely fair, Part I: the Fairness formula’, we presented the first theory of comparative and absolute fairness. Here, we relate the implications of our Fairness formula to economic theories of fair division. Our analysis makes contributions to both philosophy and economics: to the philosophical literature, we add an axiomatic discussion of proportionality and fairness. To the economic literature, we add an appealing normative theory of absolute and comparative fairn…Read more
  •  272
    Interpolation in 16-Valued Trilattice Logics
    Studia Logica 106 (2): 345-370. 2018.
    In a recent paper we have defined an analytic tableau calculus PL_16 for a functionally complete extension of Shramko and Wansing's logic based on the trilattice SIXTEEN_3. This calculus makes it possible to define syntactic entailment relations that capture central semantic relations of the logic---such as the relations |=_t, |=_f, and |=_i that each correspond to a lattice order in SIXTEEN_3; and |=, the intersection of |=_t and |=_f,. It turns out that our method of characterising these sema…Read more
  •  9
    The Modal-Epistemic Argument Self-undermined
    Sophia 62 (1): 1-15. 2023.
    In a recent article, Emanuel Rutten defends his Modal-Epistemic Argument (MEA) for the existence of God against various objections that I raised against it. In this article, I observe that Rutten’s defence fails for various reasons. Most notably though, the defence is self-undermining: the very claims that Rutten argues for in his defence yield novel counterexamples to the first premise of the MEA.
  •  3
    No Envy
    Erasmus Journal for Philosophy and Economics 14 (1). 2021.
    The important ‘no-envy’ fairness criterion has typically been attributed to Foley and sometimes to Tinbergen. We reveal that Jan Tinbergen introduced ‘no-envy’ as a fairness criterion in his article “Mathematiese Psychologie” published in 1930 in the Dutch journal Mens en Maatschappij and translated as “Mathematical Psychology” in 2021 in the Erasmus Journal for Philosophy and Economics. Our article accompanies the translation: we introduce Tinbergen’s 1930 formulation of the ‘no-envy’ criterion…Read more
  •  11
    Eerlijkheid: het proportionele-claims idee
    Algemeen Nederlands Tijdschrift voor Wijsbegeerte 112 (4): 494-498. 2020.
    Amsterdam University Press is a leading publisher of academic books, journals and textbooks in the Humanities and Social Sciences. Our aim is to make current research available to scholars, students, innovators, and the general public. AUP stands for scholarly excellence, global presence, and engagement with the international academic community.
  •  381
    Analytic Tableaux for all of SIXTEEN 3
    Journal of Philosophical Logic 44 (5): 473-487. 2015.
    In this paper we give an analytic tableau calculus P L 1 6 for a functionally complete extension of Shramko and Wansing’s logic. The calculus is based on signed formulas and a single set of tableau rules is involved in axiomatising each of the four entailment relations ⊧ t, ⊧ f, ⊧ i, and ⊧ under consideration—the differences only residing in initial assignments of signs to formulas. Proving that two sets of formulas are in one of the first three entailment relations will in general require devel…Read more
  •  149
    In this paper we introduce a Gentzen calculus for (a functionally complete variant of) Belnap's logic in which establishing the provability of a sequent in general requires \emph{two} proof trees, one establishing that whenever all premises are true some conclusion is true and one that guarantees the falsity of at least one premise if all conclusions are false. The calculus can also be put to use in proving that one statement \emph{necessarily approximates} another, where necessary approximation…Read more
  •  302
    A Gentzen Calculus for Nothing but the Truth
    Journal of Philosophical Logic 45 (4): 451-465. 2016.
    In their paper Nothing but the Truth Andreas Pietz and Umberto Rivieccio present Exactly True Logic, an interesting variation upon the four-valued logic for first-degree entailment FDE that was given by Belnap and Dunn in the 1970s. Pietz & Rivieccio provide this logic with a Hilbert-style axiomatisation and write that finding a nice sequent calculus for the logic will presumably not be easy. But a sequent calculus can be given and in this paper we will show that a calculus for the Belnap-Dunn l…Read more
  •  30
    Interpolation Methods for Dunn Logics and Their Extensions
    Studia Logica 105 (6): 1319-1347. 2017.
    The semantic valuations of classical logic, strong Kleene logic, the logic of paradox and the logic of first-degree entailment, all respect the Dunn conditions: we call them Dunn logics. In this paper, we study the interpolation properties of the Dunn logics and extensions of these logics to more expressive languages. We do so by relying on the \ calculus, a signed tableau calculus whose rules mirror the Dunn conditions syntactically and which characterizes the Dunn logics in a uniform way. In t…Read more
  •  51
    Theories of Fairness and Aggregation
    Erkenntnis 85 (3): 715-738. 2020.
    We investigate the issue of aggregativity in fair division problems from the perspective of cooperative game theory and Broomean theories of fairness. Paseau and Saunders proved that no non-trivial theory of fairness can be aggregative and conclude that theories of fairness are therefore problematic, or at least incomplete. We observe that there are theories of fairness, particularly those that are based on cooperative game theory, that do not face the problem of non-aggregativity. We use this o…Read more
  •  9
    Extreme rijkdom eerlijk verdeeld
    Algemeen Nederlands Tijdschrift voor Wijsbegeerte 109 (4): 469-474. 2017.
    Amsterdam University Press is a leading publisher of academic books, journals and textbooks in the Humanities and Social Sciences. Our aim is to make current research available to scholars, students, innovators, and the general public. AUP stands for scholarly excellence, global presence, and engagement with the international academic community.
  •  61
    The modal-epistemic argument for the existence of God is flawed
    International Journal for Philosophy of Religion 84 (3): 307-322. 2018.
    In a recent article, Emanuel Rutten has presented a novel argument for the existence of God, defined as a personal being that is the first cause of reality. An interesting feature of the argument, which caused quite a stir, is that it does not fall within any of the traditional categories of arguments for God’s existence. Rutten calls his argument a modal-epistemic one, which reflects the fact that the first premise of his argument states that all possible truths are knowable. The main purpose o…Read more
  •  69
    Dividing the indivisible: Apportionment and philosophical theories of fairness
    Politics, Philosophy and Economics 17 (1): 51-74. 2018.
    Philosophical theories of fairness propose to divide a good that several individuals have a claim to in proportion to the strength of their respective claims. We suggest that currently, these theories face a dilemma when dealing with a good that is indivisible. On the one hand, theories of fairness that use weighted lotteries are either of limited applicability or fall prey to an objection by Brad Hooker. On the other hand, accounts that do without weighted lotteries fall prey to three fairness …Read more
  •  15
    From Closure Games to Strong Kleene Truth
    Notre Dame Journal of Formal Logic 57 (2): 153-179. 2016.
    In this paper, we study the method of closure games, a game-theoretic valuation method for languages of self-referential truth developed by the author. We prove two theorems which jointly establish that the method of closure games characterizes all 3- and 4-valued strong Kleene fixed points in a novel, informative manner. Among others, we also present closure games which induce the minimal and maximal intrinsic fixed point of the strong Kleene schema.
  •  44
    What makes a knight?
    In T. Icard & R. Muskens (eds.), Interfaces: Explorations in Logic, Language and Computation, Springer Berlin. pp. 25--37. 2010.
    In Smullyan’s well known logic puzzles, the notion of a knight, which is a creature that always speaks the truth, plays an important role. Rabern and Rabern (2008) made the following observation with respect to knights. They noted that when a knight is asked (1), he gets into serious trouble.
  •  102
    Assertoric Semantics and the Computational Power of Self-Referential Truth
    Journal of Philosophical Logic 41 (2): 317-345. 2012.
    There is no consensus as to whether a Liar sentence is meaningful or not. Still, a widespread conviction with respect to Liar sentences (and other ungrounded sentences) is that, whether or not they are meaningful, they are useless . The philosophical contribution of this paper is to put this conviction into question. Using the framework of assertoric semantics , which is a semantic valuation method for languages of self-referential truth that has been developed by the author, we show that certai…Read more
  •  33
    On All Strong Kleene Generalizations of Classical Logic
    Studia Logica 104 (3): 503-545. 2016.
    By using the notions of exact truth and exact falsity, one can give 16 distinct definitions of classical consequence. This paper studies the class of relations that results from these definitions in settings that are paracomplete, paraconsistent or both and that are governed by the Strong Kleene schema. Besides familiar logics such as Strong Kleene logic, the Logic of Paradox and First Degree Entailment, the resulting class of all Strong Kleene generalizations of classical logic also contains a …Read more
  •  27
    Alternative Ways for Truth to Behave When There’s no Vicious Reference
    Journal of Philosophical Logic 43 (4): 665-690. 2014.
    In a recent paper, Philip Kremer proposes a formal and theory-relative desideratum for theories of truth that is spelled out in terms of the notion of ‘no vicious reference’. Kremer’s Modified Gupta-Belnap Desideratum (MGBD) reads as follows: if theory of truth T dictates that there is no vicious reference in ground model M, then T should dictate that truth behaves like a classical concept in M. In this paper, we suggest an alternative desideratum (AD): if theory of truth T dictates that there i…Read more
  •  84
    On the Behavior of True and False
    Minds and Machines 22 (1): 1-24. 2012.
    Uzquiano (Analysis 70:39–44, 2010 ) showed that the Hardest Logic Puzzle Ever ( HLPE ) [in its amended form due to Rabern and Rabern (Analysis 68:105–112, 2008 )] has a solution in only two questions. Uzquiano concludes his paper by noting that his solution strategy naturally suggests a harder variation of the puzzle which, as he remarks, he does not know how to solve in two questions. Wheeler and Barahona (J Philos Logic, to appear, 2011 ) formulated a three question solution to Uzquiano’s puzz…Read more
  •  103
    How to be fairer
    Synthese 194 (9): 3475-3499. 2017.
    We confront the philosophical literature on fair division problems with axiomatic and game-theoretic work in economics. Firstly, we show that the proportionality method advocated in Curtis is not implied by a general principle of fairness, and that the proportional rule cannot be explicated axiomatically from that very principle. Secondly, we suggest that Broome’s notion of claims is too restrictive and that game-theoretic approaches can rectify this shortcoming. More generally, we argue that ax…Read more
  •  271
    From Bi-facial Truth to Bi-facial Proofs
    Studia Logica 103 (3): 545-558. 2015.
    In their recent paper Bi-facial truth: a case for generalized truth values Zaitsev and Shramko [7] distinguish between an ontological and an epistemic interpretation of classical truth values. By taking the Cartesian product of the two disjoint sets of values thus obtained, they arrive at four generalized truth values and consider two “semi-classical negations” on them. The resulting semantics is used to define three novel logics which are closely related to Belnap’s well-known four valued logic…Read more
  •  37
    On the Strict–Tolerant Conception of Truth
    Australasian Journal of Philosophy 92 (1): 1-20. 2014.
    We discuss four distinct semantic consequence relations which are based on Strong Kleene theories of truth and which generalize the notion of classical consequence to 3-valued logics. Then we set up a uniform signed tableau calculus, which we show to be sound and complete with respect to each of the four semantic consequence relations. The signs employed by our calculus are,, and, which indicate a strict assertion, strict denial, tolerant assertion and tolerant denial respectively. Recently, Rip…Read more
  •  121
    In this paper, we present a framework in which we analyze three riddles about truth that are all (originally) due to Smullyan. We start with the riddle of the yes-no brothers and then the somewhat more complicated riddle of the da-ja brothers is studied. Finally, we study the Hardest Logic Puzzle Ever (HLPE). We present the respective riddles as sets of sentences of quotational languages , which are interpreted by sentence-structures. Using a revision-process the consistency of these sets is est…Read more