•  24
    A globally expressivist analysis of the indicative conditional based on the Ramsey Test is presented. The analysis is a form of ‘global’ expressivism in that it supplies acceptance and rejection conditions for all the sentence forming connectives of propositional logic and so allows the conditional to embed in arbitrarily complex sentences. The expressivist framework is semantically characterized in a restrictor semantics due to Vann McGee, and is completely axiomatized in a logic dubbed ICL. Th…Read more
  •  32
    Probability, coherent belief and coherent belief changes
    with Hans Rott
    Annals of Mathematics and Artificial Intelligence 87 (3): 259-291. 2019.
    This paper is about the statics and dynamics of belief states that are represented by pairs consisting of an agent's credences (represented by a subjective probability measure) and her categorical beliefs (represented by a set of possible worlds). Regarding the static side, we argue that the latter proposition should be coherent with respect to the probability measure and that its probability should reach a certain threshold value. On the dynamic side, we advocate Jeffrey conditionalisation as t…Read more
  • Pågående handlingar
    Norsk Filosofisk Tidsskrift 4. 1995.
  •  16
    Self‐Defeating Goals
    with Sven Ove Hansson and Karin Edvardsson Björnberg
    Dialectica 70 (4): 491-512. 2016.
    The typical function of goals is to regulate action in a way that furthers goal achievement. Goals are typically set on the assumption that they will help bring the agent closer to the desired state of affairs. However, sometimes endorsement of a goal, or the processes by which the goal is set, can obstruct its achievement. When this happens, the goal is self-defeating. Self-defeating goals are common in both private and social decision-making but have not received much attention by decision the…Read more
  •  4
    Credibility Limited Revision
    with Sven Hansson, Eduardo Ferme, and Marcelo Falappa
    Journal of Symbolic Logic 66 (4): 1581-1596. 2001.
    Five types of constructions are introduced for non-prioritized belief revision, i.e., belief revision in which the input sentence is not always accepted. These constructions include generalizations of entrenchment-based and sphere-based revision. Axiomatic characterizations are provided, and close interconnections are shown to hold between the different constructions.
  •  37
    Credibility limited revision
    with Sven Ove Hansson, Eduardo Leopoldo Fermé, and Marcelo Alejandro Falappa
    Journal of Symbolic Logic 66 (4): 1581-1596. 2001.
    Five types of constructions are introduced for non-prioritized belief revision, i.e., belief revision in which the input sentence is not always accepted. These constructions include generalizations of entrenchment-based and sphere-based revision. Axiomatic characterizations are provided, and close interconnections are shown to hold between the different constructions
  •  43
    Making sense of (in)determinate truth: the semantics of free variables
    Philosophical Studies 175 (11): 2715-2741. 2018.
    It is argued that truth value of a sentence containing free variables in a context of use, just as the reference of the free variables concerned, depends on the assumptions and posits given by the context. However, context may under-determine the reference of a free variable and the truth value of sentences in which it occurs. It is argued that in such cases a free variable has indeterminate reference and a sentence in which it occurs may have indeterminate truth value. On letting, say, x be suc…Read more
  •  111
    Conditionals in reasoning
    Synthese 171 (1). 2009.
    The paper presents a non-monotonic inference relation on a language containing a conditional that satisfies the Ramsey Test. The logic is a weakening of classical logic and preserves many of the ‘paradoxes of implication’ associated with the material implication. It is argued, however, that once one makes the proper distinction between supposing that something is the case and accepting that it is the case, these ‘paradoxes’ cease to be counterintuitive. A representation theorem is provided where…Read more
  •  6
    Logics of Belief Change without Linearity
    Journal of Symbolic Logic 65 (4): 1556-1575. 2000.
    Ever since [4], systems of spheres have been considered to give an intuitive and elegant way to give a semantics for logics of theory- or belief- change. Several authors [5, 11] have considered giving up the rather strong assumption that systems of spheres be linearly ordered by inclusion. These more general structures are called hypertheories after [8]. It is shown that none of the proposed logics induced by these weaker structures are compact and thus cannot be given a strongly complete axioma…Read more
  •  41
    The laws of non-bivalent probability
    Logic and Logical Philosophy 15 (2): 163-171. 2006.
    Non-bivalent languages (languages containing sentences that can be true, false or neither) are given a probabilitistic interpretation in terms of betting quotients. Necessary and sufficient conditions for avoiding Dutch books—the laws of non-bivalent probability—in such a setting are provided
  •  50
    The Logic of Dominance Reasoning
    Journal of Philosophical Logic 35 (1): 41-63. 2006.
    The logic of dominance arguments is analyzed using two different kinds of conditionals: indicative (epistemic) and subjunctive (counter-factual). It is shown that on the indicative interpretation an assumption of independence is needed for a dominance argument to go through. It is also shown that on the subjunctive interpretation no assumption of independence is needed once the standard premises of the dominance argument are true, but that independence plays an important role in arguing for the …Read more
  •  74
    Reasoning With Safety Factor Rules
    with Jonas Clausen
    Techné: Research in Philosophy and Technology 11 (1): 55-70. 2007.
    Safety factor rules are used for drawing putatively reasonable conclusions from incomplete datasets. The paper attempts to provide answers to four questions: “How are safety factors used?”, “When are safety factors used?”, “Why are safety used?” and “How do safety factor rules relate to decision theory?”. The authors conclude that safety factor rules should be regarded as decision methods rather than as criteria of rightness and that they can be used in both practical and theoretical reasoning. …Read more
  •  58
    The Logic of Conditional Negation
    Notre Dame Journal of Formal Logic 49 (3): 245-260. 2008.
    It is argued that the "inner" negation $\mathord{\sim}$ familiar from 3-valued logic can be interpreted as a form of "conditional" negation: $\mathord{\sim}$ is read '$A$ is false if it has a truth value'. It is argued that this reading squares well with a particular 3-valued interpretation of a conditional that in the literature has been seen as a serious candidate for capturing the truth conditions of the natural language indicative conditional (e.g., "If Jim went to the party he had a good ti…Read more
  •  78
    Changing the modal context
    Theoria 74 (4): 331-351. 2008.
    Conditionals that contain a modality in the consequent give rise to a particular semantic phenomenon whereby the antecedent of the conditional blocks possibilities when interpreting the modality in the consequent. This explains the puzzling logical behaviour of constructions like "If you don't buy a lottery ticket, you can't win", "If you eat that poison, it is unlikely that you will survive the day" and "If you kill Harry, you ought to kill him gently". In this paper it is argued that a semanti…Read more
  •  105
    Indicative conditionals:Factual or Epistemic?
    Studia Logica 88 (1): 157-194. 2008.
    It is argued that indicative conditionals are best viewed as having truth conditions (and so they are in part factual) but that these truth conditions are ‘gappy’ which leaves an explanatory gap that can only be filled by epistemic considerations (and so indicative conditionals are in part epistemic). This dual nature of indicative conditionals gives reason to rethink the relationship between logic viewed as a descriptive discipline (focusing on semantics) and logic viewed as a discipline with a…Read more
  •  26
    Vann McGee has proposed a counterexample to the Ramsey Test. In the counterexample, a seemingly trustworthy source has testified that p and that if not-p, then q. If one subsequently learns not-p, then one has reason to doubt the trustworthiness of the source and so, the argument goes, one has reason to doubt the conditional asserted by the source. Since what one learns is that the antecedent of the conditional holds, these doubts are contrary to the Ramsey Test. We argue that the counterexample…Read more
  •  47
    Resolving conflicting information
    Journal of Logic, Language and Information 7 (2): 191-220. 1998.
    Information received from different sources can be inconsistent. Even when the sources of information can be ordered on the basis of their trustworthiness, it turns out that extracting an acceptable notion of support for information is a non-trivial matter, as is the question what information a rational agent should accept. Here it is shown how a support ordering on the information can be generated and how it can be used to decide what information to accept and what not to accept. This ordering,…Read more
  •  531
    Conditionals in causal decision theory
    Synthese 190 (4): 661-679. 2013.
    This paper explores the possibility that causal decision theory can be formulated in terms of probabilities of conditionals. It is argued that a generalized Stalnaker semantics in combination with an underlying branching time structure not only provides the basis for a plausible account of the semantics of indicative conditionals, but also that the resulting conditionals have properties that make them well-suited as a basis for formulating causal decision theory. Decision theory (at least if we …Read more
  •  25
    The Pragmatic Stance: Whither Dutch Books and Money Pumps?
    Croatian Journal of Philosophy 6 (3): 319-336. 2002.
    The view that decision methods can only be justified by appeal to pragmatic considerations is defended. Pragmatic considerations are viewed as providing the underlying subject matter of decision theories. It is argued that other approaches fail to provide grounds for a normative decision theory.It is argued that preferences that can lead to pragmatically adverse outcomes in a relevantly similar possible decision situation are pragmatically unsound, even if the decision situation never arises. Th…Read more
  •  144
    On an alleged counter-example to causal decision theory
    Synthese 173 (2): 127-152. 2010.
    An alleged counterexample to causal decision theory, put forward by Andy Egan, is studied in some detail. It is argued that Egan rejects the evaluation of causal decision theory on the basis of a description of the decision situation that is different from—indeed inconsistent with—the description on which causal decision theory makes its evaluation. So the example is not a counterexample to causal decision theory. Nevertheless, the example shows that causal decision theory can recommend unratifi…Read more
  •  44
    An Expressivist Bilateral Meaning-is-Use Analysis of Classical Propositional Logic
    Journal of Logic, Language and Information 24 (1): 27-51. 2015.
    The connectives of classical propositional logic are given an analysis in terms of necessary and sufficient conditions of acceptance and rejection, i.e. the connectives are analyzed within an expressivist bilateral meaning-is-use framework. It is explained how such a framework differs from standard inferentialist frameworks and it is argued that it is better suited to address the particular issues raised by the expressivist thesis that the meaning of a sentence is determined by the mental state …Read more
  •  31
    Eligible Contraction
    Studia Logica 73 (2): 167-182. 2003.
    When a belief set is contracted only some beliefs are eligible for removal. By introducing eligibility for removal as a new semantic primitive for contraction and combining it with epistemic entrenchment we get a contraction operator with a number of interesting properties. By placing some minimal constraint upon eligibility we get an explicit contraction recipe that exactly characterises the so called interpolation thesis, a thesis that states upper and lower bounds for the amount of informatio…Read more
  •  42
    Unity and Autonomy in Expressivist Logic
    Dialectica 68 (3): 443-457. 2014.
    It is argued that expressivists can solve their problems in accounting for the unity and autonomy of logic – logic is topic independent and does not derive from a general ‘logic’ of mental states – by adopting an analysis of the logical connectives that takes logically complex sentences to express complex combinations of simple attitudes like belief and disapproval and dispositions to form such simple attitudes upon performing suppositional acts, and taking acceptance and rejection of sentences …Read more
  •  38
    A formal model of multi-agent belief-interaction
    Journal of Logic, Language and Information 15 (4): 397-422. 2006.
    A semantics is presented for belief revision in the face of common announcements to a group of agents that have beliefs about each other’s beliefs. The semantics is based on the idea that possible worlds can be viewed as having an internal-structure, representing the belief independent features of the world, and the respective belief states of the agents in a modular fashion. Modularity guarantees that changing one aspect of the world (a belief independent feature or a belief state) has no effec…Read more
  •  33
    Some logics of iterated belief change
    Studia Logica 63 (1): 49-84. 1999.
    The problems that surround iterated contractions and expansions of beliefs are approached by studying hypertheories, a generalisation of Adam Grove's notion of systems of spheres. By using a language with dynamic and doxastic operators different ideas about the basic nature of belief change are axiomatised. It is shown that by imposing quite natural constraints on how hypertheories may change, the basic logics for belief change can be strengthened considerably to bring one closer to a theory of …Read more
  •  57
    First Order Expressivist Logic
    Erkenntnis 78 (6): 1381-1403. 2013.
    This paper provides finitary jointly necessary and sufficient acceptance and rejection conditions for the logical constants of a first order quantificational language. By introducing the notion of making an assignment as a distinct object level practice—something you do with a sentence—(as opposed to a meta-level semantic notion) and combining this with the practice of (hypothetical and categorical) acceptance and rejection and the practice of making suppositions one gains a structure that is su…Read more
  •  18
    Towards an analysis of the progressive
    Nordic Journal of Philosophical Logic 5 (1): 39-59. 2000.
    No abstract
  •  33