PHIL 29622 HiPSS Tutorial: The Quarrel Between Logic and Psychology
Logic, traditionally conceived, aims to study the laws of thought. This makes it seem as though logicians share a concern with psychologists; but in fact, the proposal that logical laws can be studied empirically - also known as psychologism - came under attack by philosophers throughout the 19th and 20th centuries. The idea that logic is presupposed by all thinking was taken to disallow its empirical study, and to render the methods of psychology irrelevant to logic. For most of the 20th century, this philosophical position made sense to psychologists; at the very least, they did not seriously raise the question whether thinkers are actually rational in the sense prescribed by logic. This assumption has gradually been rejected; since the 70s, human rationality has become a central object of study for psychologists, with a focus on the defective logical patterns of thought that humans tend to exhibit. At the same time, in philosophy, the collapse of the analytic-synthetic distinction and the naturalistic turn gave way to a new conception of the relation between logic and psychology. Nowadays several fruitful research programs in the psychological study of reasoning and rationality exist side by side, and alongside them, many philosophers and logicians make room for psychological considerations. In reaction to the new sciences of rationality and to the new psychologism in logic, new forms of antipsychologism have also emerged; we will evaluate several such arguments and ask how psychologists and psychologically minded philosophers cope with them. We will conclude our inquiry with a look at the contemporary debate regarding the normative status of logic and its relation to thought.