•  235
    In his well-known 1952 dialogue Max Black describes a counterexample to the Principle of the Identity of Indiscernibles (PII). The counterexample is a world containing nothing but two purportedly indiscernible iron spheres. Reflecting on Black's example, Robert Adams uses the possibility of a world containing two almost indiscernible spheres to argue for the possibility of the indiscernible spheres world. One of Adams's almost indiscernible spheres has a small impurity, and, Adams writes, "Surel…Read more
  •  226
    Brute facts, the necessity of identity, and the identity of indiscernibles
    Pacific Philosophical Quarterly 92 (1): 1-10. 2011.
    In ‘Two Spheres, Twenty Spheres, and the Identity of Indiscernibles,’ Della Rocca argues that any counterexample to the PII would involve ‘a brute fact of non-identity [. . .] not grounded in any qualitative difference.’ I respond that Adams's so-called Continuity Argument against the PII does not postulate qualitatively inexplicable brute facts of identity or non-identity if understood in the context of Kripkean modality. One upshot is that if the PII is understood to quantify over modal as wel…Read more
  •  183
    Max Black on the identity of indiscernibles
    Philosophical Quarterly 45 (180): 350-360. 1995.
    I give a critique of the argument against the Identity of Indiscernibles found in Max Black's dialogue "The Identity of Indiscernibles". I begin by postulating and giving existence and individuation conditions for actually existent thought experiment characters on analogy with fictional characters as postulated in Peter van Inwagen's "Creatures of Fiction". I then show that Black's two-spheres thought experiment raises not one but two discernibility questions: 1) Is it true in the two-spheres th…Read more
  •  136
    In a 1994 ANALYSIS article Peter Klein and Ted Warfield show that an epistemically more coherent set of beliefs often has a smaller unconditional probability of joint truth than some of its less coherent subsets. They conclude that epistemic justification, as understood in one version of a coherence theory of justification, is not truth conducive. After getting clear about what truth conduciveness requires, I show that their argument does not tell against BonJour's coherence theory.
  •  134
    Nonbelief and the desire-as-belief thesis
    Acta Analytica 23 (2): 115-124. 2008.
    I show the incompatibility of two theses: (a) to desire the truth of p amounts to believing a certain proposition about the value of p’s truth; (b) one cannot be said to desire the truth of p if one believes that p is true. Thesis (a), the Desire-As-Belief Thesis, has received much attention since the late 1980s. Thesis (b) is an epistemic variant of Socrates’ remark in the Symposium that one cannot desire what one already has. It turns out that (a) and (b) cannot both be true if it is possible …Read more
  •  133
    Explanation and the theory of questions
    Erkenntnis 34 (2). 1991.
    In The Scientific Image B. C. van Fraassen argues that a theory of explanation ought to take the form of a theory of why-questions, and a theory of this form is what he provides. Van Fraassen's account of explanation is good, as far as it goes. In particular, van Fraassen's theory of why-questions adds considerable illumination to the problem of alternative explanations in psychodynamics. But van Fraassen's theory is incomplete because it ignores those classes of explanations that are answers no…Read more
  •  121
    Review: Conditionals in Context (review)
    Mind 116 (464): 1119-1122. 2007.
    This is a review of Christopher Gauker, CONDITIONALS IN CONTEXT (Cambridge, MA: The MIT Press, 2005).
  •  114
    This essay corrects an error in the presentation of the Paradox of the Knowledge-Plus Knower, which is the variant of Kaplan and Montague’s Knower Paradox presented in C. Cross 2001: ‘The Paradox of the Knower without Epistemic Closure,’ MIND, 110, pp. 319–33. The correction adds a universally quantified transitivity principle for derivability as an additional assumption leading to paradox. This correction does not affect the status of the Knowledge-Plus paradox as a rebuttal to an argument agai…Read more
  •  107
    'Can' and the logic of ability
    Philosophical Studies 50 (1): 53-64. 1986.
    A selection function based semantics is offered for the 'can' of ability based on the idea that 'John can run a four minute mile' is true iff John would do so under the right conditions, meaning that he would do so under at least one appropriately chosen test condition. Completeness is proved for an axiom system and semantics based on this idea, and the logic turns out to be interestingly different from any standard system of modal logic.
  •  105
    The coherence of the whole truth is a presupposition of any holistic coherence theory of justification that postulates a positive connection between justification and truth, for unless the whole truth is itself systemically coherent there is no reason to look for systemic coherence when deciding whether one is justified in accepting a given body of beliefs as true. This paper develops a formal model of holistic evidential coherence and uses this model to formalize and defend the claim that the w…Read more
  •  98
    Conditional excluded middle
    Erkenntnis 70 (2): 173-188. 2009.
    In this essay I renew the case for Conditional Excluded Middle (CXM) in light of recent developments in the semantics of the subjunctive conditional. I argue that Michael Tooley’s recent backward causation counterexample to the Stalnaker-Lewis comparative world similarity semantics undermines the strongest argument against CXM, and I offer a new, principled argument for the validity of CXM that is in no way undermined by Tooley’s counterexample. Finally, I formulate a simple semantics for the su…Read more
  •  92
    The paradox of the knower without epistemic closure
    Mind 110 (438): 319-333. 2001.
    In this essay I present a new version of the Paradox of the Knower and show that this new paradox vitiates a certain argument against epistemic closure. I then prove a theorem that relates the new paradox to epistemological scepticism. I conclude by assessing the use of the Knower in arguments against syntactical treatments of knowledge.
  •  83
    Every Proposition is a Counterfactual
    Acta Analytica 31 (2): 117-137. 2016.
    I present and discuss two logical results. The first shows that a non-trivial counterfactual analysis exists for any contingent proposition that is false in at least two possible worlds. The second result identifies a set of conditions that are individually necessary and jointly sufficient for the success of a counterfactual analysis. I use these results to shed light on the question whether disposition ascribing propositions can be analyzed as Stalnaker-Lewis conditional propositions. The answe…Read more
  •  83
    In "Backward causation and the Stalnaker-Lewis approach to counterfactuals," Analysis 62 (2002): 191–97, Michael Tooley argues that if a certain kind of backward causation is possible, then a Stalnaker-Lewis style comparative world similarity account of the truth conditions of counterfactuals cannot be sound. Tooley’s target is one particular type of semantics, but, as I show, the significance of Tooley’s example goes well beyond its consequences for any one semantics for the conditional.
  •  82
    Jonathan Bennett on 'even if'
    Linguistics and Philosophy 8 (3): 353-357. 1985.
    I show that given Jonathan Bennett's theory of 'even if,' the following statement is logically true iff the principle of conditional excluded is valid: (SE) If Q and if P wouldn't rule out Q, then Q even if P. Hence whatever intuitions support the validity of (SE) support the validity of Conditional Excluded Middle, too. Finally I show that Bennett's objection to John Bigelow's theory of the conditional can be turned into a (perhaps) more telling one, viz. that on Bigelow's theory 'if P then Q' …Read more
  •  78
    Review: Against Coherence: Truth, Probability, and Justification (review)
    Mind 115 (459): 790-793. 2006.
    This is a review of Erik J. Olsson, AGAINST COHERENCE: TRUTH, PROBABILITY AND JUSTIFICATION (Oxford: Clarendon Press, 2005).
  •  78
    A Logical Transmission Principle for Conclusive Reasons
    Australasian Journal of Philosophy 93 (2): 353-370. 2015.
    Dretske's conclusive reasons account of knowledge is designed to explain how epistemic closure can fail when the evidence for a belief does not transmit to some of that belief's logical consequences. Critics of Dretske dispute the argument against closure while joining Dretske in writing off transmission. This paper shows that, in the most widely accepted system for counterfactual logic , conclusive reasons are governed by an informative, non-trivial, logical transmission principle. If r is a co…Read more
  •  76
    In “The Paradox of the Knower without Epistemic Closure”, MIND 110:319-33, 2001, I develop a version of the Knower Paradox which does not assume epistemic closure, and I use it to argue that the original Knower Paradox does not support an argument against epistemic closure. In “The Paradox of the Knower without Epistemic Closure?”, MIND 113:95-107, 2004, Gabriel Uzquiano, using his own result, argues that my rebuttal to the anti-closure argument is not successful. I respond here by arguing that…Read more
  •  65
    Embedded counterfactuals and possible worlds semantics
    Philosophical Studies 173 (3): 665-673. 2016.
    Stephen Barker argues that a possible worlds semantics for the counterfactual conditional of the sort proposed by Stalnaker and Lewis cannot accommodate certain examples in which determinism is true and a counterfactual Q > R is false, but where, for some P, the compound counterfactual P > (Q > R) is true. I argue that the completeness theorem for Lewis’s system VC of counterfactual logic shows that Stalnaker–Lewis semantics does accommodate Barker’s example, and I argue that its doing so should…Read more
  •  63
    From worlds to probabilities: A probabilistic semantics for modal logic
    Journal of Philosophical Logic 22 (2). 1993.
    I give a probabilistic semantics for modal logic in which modal operators function as quantifiers over Popper functions in probabilistic model sets, thereby generalizing Kripke's semantics for modal logic.
  •  59
    Temporal necessity and the conditional
    Studia Logica 49 (3): 345-363. 1990.
    Temporal necessity and the subjunctive conditional appear to be related by the principle of Past Predominance, according to which past similarities and differences take priority over future similarities and differences in determining the comparative similarity of alternative possible histories with respect to the present moment. R. H. Thomason and Anil Gupta have formalized Past Predominance in a semantics that combines selection functions with branching time; in this paper I show that Past Pred…Read more
  •  58
    Counterfactuals and event causation
    Australasian Journal of Philosophy 70 (3). 1992.
    I compare the failure of counterfactual dependence as a criterion of event causation to the failure of stochastic dependence as a criterion of causal law. Counterexamples to the stochastic analysis arise from cases of Simpson's Paradox, and Nancy Cartwright has suggested a way of transforming the stochastic analysis into something that avoids these counterexample. There is an analogical relationship between cases of Simpson's Paradox and cases of causal overdetermination. I exploit this analogi…Read more
  •  58
    A characterization of imaging in terms of Popper functions
    Philosophy of Science 67 (2): 316-338. 2000.
    Despite the results of David Lewis, Peter Gärdenfors, and others, showing that imaging and classical conditionalization coincide only in the most trivial probabilistic models of belief revision, it turns out that imaging on a proposition A can always be described via Popper function conditionalization on a proposition that entails A. This result generalizes to any method of belief revision meeting certain minimal requirements. The proof is illustrated by an application of imaging in the context …Read more
  •  57
    This is a review of Jean Curthoys and Victor H. Dudman, VICTOR DUDMAN'S GRAMMAR AND SEMANTICS (Hampshire, UK: Palgrave Macmillan, 2012).
  •  56
    Armstrong And The Problem Of Converse Relations
    Erkenntnis 56 (2): 215-227. 2002.
    In "A World of States of Affairs" David Armstrong offers a comprehensive metaphysics based on the thesis that the world consists of states of affairs. Among the entities postulated by Armstrong's theory are relations, including non-symmetrical relations, and while Armstrong does not agree with Russell that all relations have a direction or definite order among their places, he does explicitly acknowledge that the slots of a non-symmetrical relation have a definite order or direction. I first sho…Read more
  •  55
    Nonmonotonic Inconsistency
    Artificial Intelligence 149 (2): 161-178. 2003.
    Nonmonotonic consequence is the subject of a vast literature, but the idea of a nonmonotonic counterpart of logical inconsistency—the idea of a defeasible property representing internal conflict of an inductive or evidential nature—has been entirely neglected. After considering and dismissing two possible analyses relating nonmonotonic consequence and a nonmonotonic counterpart of logical inconsistency, this paper offers a set of postulates for nonmonotonic inconsistency, an analysis of nonmonot…Read more
  •  54
    Review: Counterfactuals and Probability by Moritz Schulz (review)
    Australasian Journal of Philosophy 1-1. forthcoming.
    This is a review of Moritz Schulz, COUNTERFACTUALS AND PROBABIITY (Oxford: Oxford University Press, 2017).
  •  47
    Belief Revision, Non-Monotonic Reasoning, and the Ramsey Test
    In Kyburg Henry E., Loui Ronald P. & Carlson Greg N. (eds.), Knowledge Representation and Defeasible Reasoning, Kluwer Academic Publishers. pp. 223--244. 1990.
    Peter Gärdenfors has proved (Philosophical Review, 1986) that the Ramsey rule and the methodologically conservative Preservation principle are incompatible given innocuous-looking background assumptions about belief revision. Gärdenfors gives up the Ramsey rule; I argue for preserving the Ramsey rule and interpret Gärdenfors's theorem as showing that no rational belief-reviser can avoid reasoning nonmonotonically. I argue against the Preservation principle and show that counterexamples to it alw…Read more
  •  43
    This is a review of CONDITIONALS: FROM PHILOSOPHY TO COMPUTER SCIENCE, edited by Crocco G., del Cerro L. Fariñas, and Herzig A., Studies in logic and computation, no. 5, Clarendon Press, Oxford University Press, Oxford and New York 1995.
  •  41
    [IMPORTANT CORRECTION - See end of abstract.] In Syntactical Treatments of Modality, with Corollaries on Reflexion Principles and Finite Axiomatizability, Acta Philosophica Fennica 16 (1963), 153–167, Richard Montague shows that the use of a single syntactic predicate (with a context-independent semantic value) to represent modalities of alethic necessity and idealized knowledge leads to inconsistency. In A Note on Syntactical Treatments of Modality, Synthese 44 (1980), 391–395, Richmond Thomaso…Read more