ABSTRACT
Traditional syllogisms were first devised by Aristotle, and for centuries were believed to be the basis of all rational thought. A comment is in order about the terminology used to describe syllogisms. Johnson-Laird and his colleagues have adopted a different way of describing syllogisms, based on the fact that they allow conclusions in both directions, and conclusions going from the predicate term to the subject term can alter the figure of the syllogism. Most people, when they have it explained to them, will accept the validity of the logic underlying syllogisms. However, when actually confronted by exercises in syllogistic reasoning, people make a large number of errors. Conceptually, the task of solving syllogisms can be broken down into three stages. First, it is necessary to interpret the premises. Second, the information in the two premises must be combined. And, third, a response must be produced.
