Is there a difference between believing and merely understanding an idea? R. Descartes (e.g., 1641 ) thought so. He considered the acceptance and rejection of an idea to be alternative outcomes of an effortful assessment process that occurs subsequent to the automatic comprehension of that idea. This article examined B. Spinoza’s (1982) alternative suggestion that (1) the acceptance of an idea is part of the automatic comprehension of that idea and (2) the rejection of an idea occurs subsequent to, and more effortfully than, its acceptance. In this view, the mental representation of abstract ideas is quite similar to the mental representation of physical objects: People believe in the ideas they comprehend, as quickly and automatically as they believe in the objects they see. Research in social and cognitive psychology suggests that Spinoza’s model may be a more accurate account of human belief than is that of Descartes.
Gilbert, D. T. (1991). How mental systems believe. American Psychologist, 46(2), 107-119.