The hypothetical syllogism is invalid in standard interpretations of conditional sentences. Many arguments of this sort are quite compelling, though, and you can wonder what makes them so. I shall argue that it is our parsimony in regard to connections among events and states of affairs. All manner of things just might, for all we know, be bound up with one another in all sorts of ways. But ordinarily it is better, being simpler, to assume they are unconnected. In so (...) doing, we jump to the conclusions of some compelling but invalid arguments. (shrink)

This papers deals with examples offered by Adams, Austin and others which seem to show that `if' does not conform to all of the laws of the conditional. These a reconciled by treating them as conjunctions with embedded modalities.

I defend the view that the truth conditions of the ordinary indicative conditional are those of the material conditional. This is done via a discussion of assertability and by appeal to conventional implicature rather than conversational implicature.

It is widely agreed that contraposition, strengthening the antecedent and hypothetical syllogism fail for subjunctive conditionals. The following putative counter-examples are frequently cited, respectively.

Knowledge of the basic rules of logic is often thought to be distinctive, for it seems to be a case of non-inferential a priori knowledge. Many philosophers take its source to be different from those of other types of knowledge, such as knowledge of empirical facts. The most prominent account of knowledge of the basic rules of logic takes this source to be the understanding of logical expressions or concepts. On this account, what explains why such knowledge is distinctive is (...) that it is grounded in semantic or conceptual understanding. However, I show that this cannot be the correct account of knowledge of the basic rules of logic, because it is open to Gettier-style counter-examples. (shrink)

(No abstract is available for this citation).

Content and, to a lesser degree, epistemic or inferential conditionals regularly invite conditional perfection as a non-monotonic inference or conversational implicature. Conditional perfection (henceforth CP) is the natural language tendency to perfect conditionals (if A then C) into their corresponding biconditionals (if and only if A, then C) through the mediation of an if not-A, then not-C conditional. In the literature there is some controversy regarding the pragmatic principle by which CP is derived, but there seems to be silent agreement (...) about the defeasibility of CP. In this paper we argue that the if not-A, then not-C CP inference is indefeasible with particular conditional utterance types where cancellation contrasts with the additional propositional attitude expressed by those conditional utterance types. The indefeasibility of the if not-A, then not-C CP inference can further be accounted for in terms of the pragmatic principle by which it is derived. (shrink)

Classical logic yields counterintuitive results for numerous propositional argument forms. The usual alternatives (modal logic, relevance logic, etc.) generate counterintuitive results of their own. The counterintuitive results create problems—especially pedagogical problems—for informal logicians who wish to use formal logic to analyze ordinary argumentation. This paper presents a system, PL– (propositional logic minus the funny business), based on the idea that paradigmatic valid argument forms arise from justificatory or explanatory discourse. PL– avoids the pedagogical difficulties without sacrificing insight into argument.

This paper argues that pragmatic considerations similar to the ones that Grice has shown pertain to assertability pertain to acceptability. It further shows how this should affect some widely held epistemic principles. The idea of a pragmatics of belief is defended against some seemingly obvious objections.

In "Material Implications" (1992), mathematical discourse was said to be different from ordinary discourse, with the discussion centering around conditionals. This paper shows how.

Demonstrates that the "paradoxes of material implication" are only apparent, sticking entirely within the confines of classical logic.

We put forth a theory of conditional elements which can be used to dismiss apparent challenges to the truth-functionality of the conditional without apparent circularity. In the process, we refine the ideas of Yoes, published in an earlier paper in this journal, broadening and deepening them.