Some Empirical Justification for a Theory of Natural Propositional Logic

Evidence supporting a particularRepertory as the repertory of the kinds of inferences basic to the propositional reasoning of adults untutored in logic is presented.

Abstract

Within psychology, there are three approaches to the issue of the relation of logic to reasoning. One approach emphasizes nonlogical processes and biases. The second approach posits that subjects proceed by constructing a mental model of the information given and reason from the model. The third approach assumes that reasoning includes logical principles and that it has been the starting point for a substantial body of work in recent years. This chapter presents evidence supporting a particular repertory as the repertory of the kinds of inferences basic to the propositional reasoning of adults untutored in logic. The measures of the difficulty of direct reasoning problems can be predicted from the number of inferences of this repertory needed to solve a problem and can very well be predicted if the problem length and the kind of inference are also taken into account. The repertory was incorporated into a reasoning program that consists of a direct reasoning routine, coupled with some strategies to be used when the routine fails to solve a problem.