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LINGUISTIX&LOGIK, Tony Marmo's blog
Saturday, 12 March 2005

Now Playing: REPOSTED

Supervaluationism and Paraconsistency

by Achille C. Varzi

Supervaluational semantics have been applied rather successfully to a variety of phenomena involving truth-value gaps, such as vagueness, lack of reference, sortal incorrectedness. On the other hand, they have not registered a comparable fortune (if any) in connection with truth-value gluts, i.e., more generally, with semantic phenomena involving overdeterminacy or inconsistency as opposed to indeterminacy and incompleteness. In this paper I review some basic routes that are available for this purpose. The outcome is a family of semantic systems in which (i) logical truths and falsehoods retain their classical status even in the presence gaps and gluts, although (ii) the general notions of satifiability and refutability are radically non-classical .

Posted by Tony Marmo at 00:01 GMT
Updated: Sunday, 13 March 2005 01:04 GMT


Paraconsistent logic from a modal viewpoint

By Jean-Yves Beziau

In this paper we study paraconsistent negation as a modal operator, considering the fact that the classical negation of necessity has a paraconsistent behavior. We examine this operator on the one hand in the modal logic S5 and on the other hand in some new four-valued modal logics.

Keywords: Modal logic; Paraconsistent logic; Negation; Square of opposition

Appeared at the Journal of Applied Logic.

Posted by Tony Marmo at 00:01 GMT
Updated: Sunday, 13 March 2005 01:05 GMT
Friday, 11 March 2005



Professor Cesar Lattes, one of the most important Physicists of the world, died on the 8th day of March this year, in the University Hospital of Campinas. He was 80 years old. His most famous contribution to Physics was his important participation in the discovery of the pi meson, in 1947.

Later he became the founder of the Department of Cosmic Rays and Chronology of the "Gleb Wataghin" Physics Institute, at the State University of Campinas, and helped to erect many laboratories throughout Brazil.

He died of a myocardial infarction, and left four daughters and nine grandchildren.

Posted by Tony Marmo at 16:43 GMT


Counterfactuals and Preemptive Causation

By Jonardon Ganeri, Paul Noordhof & Murali Ramachandran

David Lewis modified his original theory of causation in response to the problem of late preemption (see 1973b; 1986b: 193-212). However, as we will see, there is a crucial difference between genuine and preempted causes that Lewis must appeal to if his solution is to work. We argue that once this difference is recognized, an altogether better solution to the preemption problem presents itself.

Posted by Tony Marmo at 00:01 GMT
Updated: Friday, 11 March 2005 11:03 GMT


An Axiomatic Characterization of Causal Counterfactuals

By David Galles & Judea Pearl

This paper studies the causal interpretation of counterfactual sentences using a modifiable structural equation model. It is shown that two properties of counterfactuals, namely, composition and effectiveness, are sound and complete relative to this interpretation, when recursive (i.e., feedback-less) models are considered. Composition and eectiveness also hold in Lewis's closest-world semantics, which implies that for recursive models the causal interpretation imposes no restrictions beyond those embodied in Lewis's framework. A third property, called reversibility, holds in nonrecursive causal models but not in Lewis's closest-world semantics, which implies that Lewis's axioms do not capture some properties of systems with feedback. Causal inferences based on counterfactual analysis are exemplied and compared to those based on graphical

Keywords: Causality, counterfactuals, interventions, structural equations, policy analysis, graphical models

Posted by Tony Marmo at 00:01 GMT
Updated: Friday, 11 March 2005 11:03 GMT

Topic: Interconnections

Defending Time-Symmetrized Quantum Counterfactuals

By Lev Vaidman

Recently, several authors have criticized the time-symmetrized quantum theory originated by the work of Aharonov et al. (1964). The core of this criticism was a proof, appearing in various forms, which showed that the counterfactual interpretation of time-symmetrized quantum theory cannot be reconciled with standard quantum theory. I, (Vaidman, 1996a, 1997) have argued that the apparent contradiction is due to a logical error and introduced consistent time-symmetrized quantum counterfactuals. Here I repeat my arguments defending the time-symmetrized quantum theory and reply to the criticism of these arguments by Kastner (1999).

Posted by Tony Marmo at 00:01 GMT
Updated: Friday, 11 March 2005 11:14 GMT


Settling the Interpretation of Counterfactuals

By Lynn Nichols

This research contributes to the growing body of work on the role of context change in the interpretation of counterfactual conditionals. One result of the study was the delimitation of where context change and pragmatic factors external to the conditional are not involved in the construction of counterfactual meaning. With respect to the phenomena that had formerly led some to conclude that counterfactual interpretation derives from an implicature, two issues were resolved. First, when real (strict) counterfactuals were properly identified among the class of English non-indicative conditionals, it was revealed that the phenomena in question are not in fact found with counterfactuals. Second, these phenomena are not the result of implicature effects after all, rather they represent the settling of a truth value previously under consideration. The latter sort of interpretation has been referred to here as a live option interpretation, borrowing a term from Stalnaker (1975); Karttunen and Peters (1979) referred to this class as hypothetical, but live option more accurately characterizes the truth of these propositions as under consideration in the course of the conditional. On the basis of these findings, the case was made that counterfactual interpretation derives from internal compositional semantics.

Posted by Tony Marmo at 00:01 GMT
Updated: Friday, 11 March 2005 11:01 GMT
Wednesday, 9 March 2005

Topic: Ontology&possible worlds

Who's Afraid of Impossible Worlds?

By Edwin D. Mares

A theory of ersatz impossible worlds is developed to deal with the problem of counterpossible conditionals. Using only tools standardly in the toolbox of possible worlds theorists, it is shown that we can construct a model for counterpossibles. This model is a natural extension of Lewis's semantics for counterfactuals, but instead of using classical logic as its base, it uses the logic LP.

Source: Notre Dame J. Formal Logic ?38 (1997), no. 4, 516?526

Posted by Tony Marmo at 00:01 GMT
Tuesday, 8 March 2005

Topic: Cognition & Epistemology

Content and context effects in childrens and adults' conditional reasoning

By Pierre Barrouillet & Jean-Francois Lecas

We have recently shown that children [i.e. adolescents] interpret conditional sentences with binary terms (e.g., male/female) in both the antecedent and the consequent as biconditionals (Barrouillet & Lecas, 1998). We hypothesized that the same effect can be obtained with conditionals that do not contain binary terms provided that they are embedded in a context that restricts to only two the possible values on both the antecedent and the consequent. In the present experiment, we asked 12-year- old children, 15-year-old children, and adults to draw conclusions from conditional syllogisms that involved three types of conditional sentence:
(1) conditionals with binary terms (BB),

(2) conditionals with non-binary terms (NN), and

(3) conditionals with non-binary terms embedded in a restrictive context (NNR).

As we predicted, BB conditionals elicited more biconditional response patterns than did NN conditionals in all age groups. On the other hand, manipulating the context had the same effect in children but not in adults. Content and context constraints on conditional reasoning along with developmental issues are discussed within the framework of the mental models theory.

Posted by Tony Marmo at 10:21 GMT

Topic: Counterfactuals

A Computational Model of Counterfactual Thinking: The Temporal Order Effect

By Clare R. Walsh & Ruth M.J. Byrne

People generate counterfactual alternatives to reality when they think about how things might have happened differently, if only. There are considerable regularities in the sorts of past events that people mentally undo, for example, they tend to mentally undo the most recent event in an independent sequence. Consider a game in which two contestants will win #1000 if they both pick cards from the same color suite. The first player picks black and the second red and they lose. Most people spontaneously undo the outcome by thinking, if only the second player had picked black. We describe a computational model that simulates our theory of the mental representations and cognitive processes underlying this temporal order effect. The computer model is corroborated by tests of the novel predictions of our theory: it should be possible to reverse the temporal order effect by manipulating the way in which the winning conditions are described.

Posted by Tony Marmo at 10:05 GMT
Updated: Sunday, 4 December 2005 01:06 GMT

Topic: Counterfactuals

Counterfactuals and Policy Analysis in Structural Models

By Alexander Balke & Judea Pearl

Evaluation of counterfactual queries (e.g. If A were true, would C have been true?) is important to fault diagnosis, planning, determination of liability, and policy analysis. We present a method for evaluating counterfactuals when the underlying causal model is represented by structural models { a nonlinear generalization of the simultaneous equations models commonly used in econometrics and social sciences. This new method provides a coherent means for evaluating policies involving the control of variables which, prior to enacting the policy were inuenced by other variables in the system.

Posted by Tony Marmo at 00:01 GMT
Updated: Sunday, 4 December 2005 01:08 GMT

Topic: Counterfactuals

Counterfactuals and Updates as Inverse Modalities

By Mark Ryan and Pierre-Yves Schobbens

We point out a simple but hitherto ignored link between the theory of updates, the theory of counterfactuals, and classical modal logic: update is a classical existential modality, counterfactual is a classical universal modality, and the accessibility relations corresponding to these modalities are inverses. The Ramsey Rule (often thought esoteric) is simply an axiomatisation of this inverse relationship.

We use this fact to translate between rules for updates and rules for counterfactuals. Thus, Katsuno and Mendelzon?s postulates U1--U8 are translated into counterfactual rules C1--C8 (Table VII), and many of the familiar counterfactual rules are translated into rules for updates (Table VIII). Our conclusions are summarised in Table V.

From known properties of inverse modalities we deduce that not all rules for updates may be translated into rules for counterfactuals, and vice versa. We present a syntactic condition which is sufficient to guarantee that a translation from update to counterfactual (or vice versa) is possible.

Posted by Tony Marmo at 00:01 GMT
Updated: Sunday, 4 December 2005 07:09 GMT
Monday, 7 March 2005


Possible worlds semantics for credulous and contraction inference

By Alexander Bochman

A possible worlds semantics is suggested for a broad class of nonmonotonic inference relations, including not only traditional skeptical ones, but also credulous and contraction inference. The semantics could be used to provide a canonical framework for studying and comparing different kinds of nonmonotonic inference.

Posted by Tony Marmo at 11:42 GMT
Updated: Monday, 7 March 2005 11:44 GMT

Topic: Counterfactuals

When Possibility Informs Reality: Counterfactual Thinking as a Cue to Causality

By Barbara A. Spellman & David R. Mandel

People often engage in counterfactual thinking, that is, imagining alternatives to the real world and mentally playing out the consequences. Yet the counterfactuals people tend to imagine are a small subset of those that could possibly be imagined. There is some debate as to the relation between counterfactual thinking and causal beliefs. Some researchers argue that counterfactual thinking is the key to causal judgments; current research suggests, however, that the relation is rather complex. When people think about counterfactuals, they focus on ways to prevent bad or uncommon outcomes; when people think about causes, they focus on things that covary with outcomes. Counterfactual thinking may affect causality judgments by changing beliefs about the probabilities of possible alternatives to what actually happened, thereby changing beliefs as to whether a cause and effect actually covary. The way in which counterfactual thinking affects causal attributions may have practical consequences for mental health and the legal system.

Current Directions in Psychological Science Volume 8 Issue 4 Page 120 - August 1999

Posted by Tony Marmo at 00:01 GMT
Updated: Sunday, 4 December 2005 07:11 GMT

Now Playing: REPOSTED
Topic: Counterfactuals

Counterfactual Thinking as a Mechanism in Narrative Persuasion

by Nurit Tal-Or, David S. Boninger, Amir Poran and Faith Gleicher

Two experiments examined the impact of counterfactual thinking on persuasion. Participants in both experiments were exposed to short video clips in which an actor described a car accident that resulted in serious injury. In the narrative description, the salience of a counterfactual was manipulated by either explicitly including the counterfactual in the narrative or by not including it. An examination of attitudes related to traffic safety supported the hypothesis that the inclusion of a counterfactual in narrative enhances the persuasive impact of the narrative. The first study (N= 50) demonstrated this effect in the short-term, and the second study ( N= 61) replicated the short-term effects while also demonstrating the temporal persistence of the initial changes in attitudes. Both studies highlighted potential limiting conditions of these effects. The first study showed that the impact of counterfactuals on persuasion is most potent when the self, rather than another person, is the focus of blame in the counterfactual. The second study revealed that attitude changes persist over time when the counterfactuals are self-generated, but not when they are spoon-fed to the participant. Results are discussed in the context of understanding the characteristics of counterfactual thoughts that enable them to enhance the persuasive impact of narrative.

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Posted by Tony Marmo at 00:01 GMT
Updated: Sunday, 4 December 2005 07:10 GMT

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