ABSTRACT
Despite several decades of debate, disagreement still exists about the nature and development of logical reasoning. The present chapter focuses on two areas that are central to this debate. The ®rst deals with the place of a mental logic in the reasoning process. On one side of the debate this is considered essential because it provides a structure on which propositional content is af®xed. Dif®culties in deductive reasoning can be understood as deviations from this normative structure. On the other side, mental logic is considered unnecessary and provides nothing to the understanding of reasoning. From this perspective, performance on tasks that appear to entail deductive reasoning are explained by procedural, information-processing features of thought that are unrelated to any formal logic structure. This latter understanding leads to a second area of disagreement, which concerns whether the processes involved in reasoning are domain speci®c or domain general. This chapter attempts to reconcile these two debates by presenting a competence±procedural theory of reasoning and its development. According to this theory, reasoning requires the development of a domain general mental logical competence, but access and implementation of this competence are limited by procedural dif®culties that may be domain general or domain speci®c.
