Mental Models and Deduction

Abstract

In Deduction, Johnson-Laird and Byrne have made an extremely important contribution to the study of cognition by providing a unified theory of all types of deduction, including modal inferences. Their theory is that, contrary to the traditional view, deduction is not rule-based but model-based reasoning, and the central cognitive process involves a model-based search for counterexamples to conclusions. Although the author believes that Johnson-Laird and Byrne are right about the significance of mental models when it comes to certain types of deduction, their quest for a single cognitive process underlying all types of deductive inference has forced them to adopt the logician's notion of a model rather than a more psychological one. As a result, they are open to criticism. In this article, the author shows how mental models actually work in the case of deduction. However, the mental models discussed are a far cry from the mental models found in Deduction.