Abstract

The mental logic theory proposes that people think following a logic. That logic is not the classical one, but a special mental logic. Mental logic is akin to classical logic. However, there are important differences between them. One of those differences is that, while in classical logic Modus Tollendo Tollens is an acceptable inference, in mental logic only sophisticated individuals usually derive the right conclusion in that inference. This paper, following Carnap's framework, tries to offer a reduction sentence to gradually confirm that thesis from the mental logic theory. The paper takes two exceptions into account: the cases in which unsophisticated individuals also apply Modus Tollendo Tollens, and the cases in which even sophisticated individuals cannot apply that very inference.