Against Preservation

Bradley offers a quick and convincing argument that no Boolean semantic theory for conditionals can validate a very natural principle concerning the relationship between credences and conditionals. We argue that Bradley’s principle, Preservation, is, in fact, invalid; its appeal arises from the validity of a nearby, but distinct, principle, which we call Local Preservation, and which Boolean semantic theories can non-trivially validate

New Psychological Paradigm for Conditionals and General de Finetti Tables

International audienceThe new Bayesian paradigm in the psychology of reasoning aims to integrate the study of human reasoning, decision making, and rationality. It is supported by two findings. One, most people judge the probability of the indicative conditional, P(if A then B), to be the conditional probability, P(B|A), as implied by the Ramsey test. Two, they judge if A then B to be void when A is false. Their three-valued response table used to be called 'defective', but should be termed the de Finetti table. We show how to study general de Finetti truth tables for negations, conjunctions, disjunctions, and conditionals

Two Sides of Modus Ponens

McGee (1985) argues that it is sometimes reasonable to accept both x and x->(y->z) without accepting y->z, and that modus ponens is therefore invalid for natural language indicative conditionals. Here, we examine McGee's counterexamples from a Bayesian perspective. We argue that the counterexamples are genuine insofar as the joint acceptance of x and x->(y->z) at time t does not generally imply constraints on the acceptability of y->z at t, but we use the distance-based approach to Bayesian learning to show that applications of modus ponens are nevertheless guaranteed to be successful in an important sense. Roughly, if an agent becomes convinced of the premises of a modus ponens argument, then she should likewise become convinced of the argument's conclusion. Thus we take McGee's counterexamples to disentangle and reveal two distinct ways in which arguments can convince. Any general theory of argumentation must take stock of both

Two Sides of Modus Ponens

McGee (1985) argues that it is sometimes reasonable to accept both x and x->(y->z) without accepting y->z, and that modus ponens is therefore invalid for natural language indicative conditionals. Here, we examine McGee's counterexamples from a Bayesian perspective. We argue that the counterexamples are genuine insofar as the joint acceptance of x and x->(y->z) at time t does not generally imply constraints on the acceptability of y->z at t, but we use the distance-based approach to Bayesian learning to show that applications of modus ponens are nevertheless guaranteed to be successful in an important sense. Roughly, if an agent becomes convinced of the premises of a modus ponens argument, then she should likewise become convinced of the argument's conclusion. Thus we take McGee's counterexamples to disentangle and reveal two distinct ways in which arguments can convince. Any general theory of argumentation must take stock of both

Indicative Conditionals Without Iterative Epistemology

This paper argues that two widely accepted principles about the indicative conditional jointly presuppose the falsity of one of the most prominent arguments against epistemological iteration principles. The first principle about the indicative conditional, which has close ties both to the Ramsey test and the “or-to-if” inference, says that knowing a material conditional suffices for knowing the corresponding indicative. The second principle says that conditional contradictions cannot be true when their antecedents are epistemically possible. Taken together, these principles entail that it is impossible to be in a certain kind of epistemic state: namely, a state of ignorance about which of two partially overlapping bodies of knowledge corresponds to one’s actual one. However, some of the more popular “margin for error” style arguments against epistemological iteration principles suggest that such states are not only possible, but commonplace. I argue that the tension between these views runs deep, arising just as much for non-factive attitudes like belief, presupposition, and certainty. I also argue that this is worse news for those who accept the principles about the indicative conditional than it is for those who reject epistemological iteration principles

Probabilities, causation, and logic programming in conditional reasoning: reply to Stenning and Van Lambalgen (2016)

Oaksford and Chater (2014, Thinking and Reasoning, 20, 269–295) critiqued the logic programming (LP) approach to nonmonotonicity and proposed that a Bayesian probabilistic approach to conditional reasoning provided a more empirically adequate theory. The current paper is a reply to Stenning and van Lambalgen's rejoinder to this earlier paper entitled ‘Logic programming, probability, and two-system accounts of reasoning: a rejoinder to Oaksford and Chater’ (2016) in Thinking and Reasoning. It is argued that causation is basic in human cognition and that explaining how abnormality lists are created in LP requires causal models. Each specific rejoinder to the original critique is then addressed. While many areas of agreement are identified, with respect to the key differences, it is concluded the current evidence favours the Bayesian approach, at least for the moment

Causal Conditionals, Tendency Causal Claims and Statistical Relevance

Indicative conditionals and tendency causal claims are closely related to each other (e.g., Frosch and Byrne 2012), but despite these connections, they are usually studied separately. A unifiying framework could consist in their dependence on probabilistic factors such as statistical relevance, but theoretical research along these lines (e.g., Eells 1991; Douven 2008, 2016) needs to be strengthened by more empirical results. This paper closes that gap and presents empirical results on how judgments on tendency causal claims and indicative conditionals are driven by probabilistic factors, and how these factors (in particular statistical relevance) differ in their predictive power for both causal and conditional claims

The experimental philosophy of logic and formal epistemology:Conditionals

Classical logic was long believed to provide the norms of reasoning. But more recently researchers interested in the norms of reasoning have shifted their attention toward probability theory and various concepts and rules that can be defined in probabilistic terms. In philosophy, this shift gave rise to formal epistemology, while in psychology, it led to the New Paradigm psychology of reasoning. Whereas there has traditionally been a clear division of labor between philosophers and psychologists working on reasoning, the past decade has seen an increasing collaboration between philosophers and psychologists, from which an experimental philosophy of logic and formal epistemology emerged. An area in which the fruits of this collaboration have been par-ticularly in evidence is the research concerned with conditionals and conditional rea-soning. This chapter showcases contributions to this area to underline the value of the said branch of experimental philosophy more generally.</p

Conditionals and Propositions in Semantics

The project of giving an account of meaning in natural languages goes largely by assigning truth-conditional content to sentences. I will call the view that sentences have truth-conditional content propositionalism as it is common to identify the truth-conditional content of a sentence with the proposition it expresses. This content plays an important role in our explanations of the speech-acts, attitude ascriptions, and the meaning of sentences when they appear as parts of longer sentences. Much work in philosophy of language and linguistics semantics over the last halfcentury has aimed to characterize the truth-conditional content of different aspects of language