Perception and Proper Explanatory Width

Abstract

Marr's theory of vision is often said to exemplify wide psychology. The claim rests primarily on Marr's appeal to a high level theory of computational functions. I agree that Marr's theory embodies an exemplary form of wide psychology; what is exemplary about it is the appeal to perceptual tasks. But I argue that the result of invoking task considerations is that we should not adhere to Marr's own conception of proper explanatory width. There is no one conception of width that has a priviledged place in explanation.