Published online by Cambridge University Press: 01 January 2022
The view that the relationship between minds and brains can be thought of on the model of software and hardware is pervasive. The most common versions of the view, known as functionalism in philosophy of mind, hold that minds are realized by brains. The question arises, What is the realization relation? I approach the question of realization through a case study: David Marr's (1982) computational account of early visual processing. Marr's work is instructive because it is the textbook case of the hierarchy of mechanisms that has seemed to bear out the arguments of functionalist philosophers and cognitive scientists. I argue that realization as employed by Marr has some but not all of the characteristics that it is usually taken to have.
For valuable comments and discussion, I am indebted to the participants and audience of the PSA 2002 symposium “Realization and Explanation in Neuroscience,” especially Carl Craver, Rob Wilson, Barbara Von Eckhardt, Jeffrey Poland, Peter Machamer, and Stuart Glennan. I am also grateful for many conversations about realization with Carl Gillett and Larry Shapiro.