Reasoning, logic, and psychology

We argue that reasoning has been conceptualized so narrowly in what is known as ‘psychology of reasoning’ that reasoning's relevance to cognitive science has become well‐nigh invisible. Reasoning is identified with determining whether a conclusion follows validly from given premises, where ‘valid’ is taken to mean ‘valid according to classical logic’. We show that there are other ways to conceptualize reasoning, more in line with current logical theorizing, which give it a role in psychological processes ranging from (verbal) discourse comprehension to (nonverbal) planning. En route we show that formal logic, at present marginalized in cognitive science, can be an extremely valuable modeling tool. In particular, there are cases in which probabilistic modeling must fail, whereas logical models do well.