Logic, Pragmatics, and Types of Conditionals

Abstract

Johnson-Laird and Byrne distinguished ten kinds of conditionals. Their framework was the mental models theory and they attributed different combinations of semantic possibilities to those ten types of conditionals. Based on such combinations, the mental models theory has clear predictions for reasoning tasks, including those kinds of conditionals and involving reasoning schemata such as Modus Ponens, Modus Tollens, the affirming the consequent fallacy, and the denying the antecedent fallacy. My aim in this paper is to show that the predictions of the mental logic theory for those reasoning tasks are exactly the same as those of the mental models theory, and that, therefore, such tasks are not useful to decide which of the two theories is correct.

Key words： conditional; mental logic; mental-models; pragmatics; reasoning