It is widely believed that the mind can be studied in isolation from the details of its physical embodiment and environmental surroundings. This is a form of residual Cartesianism which cognitive science can ill afford. Arguments are presented to show that cognitive powers should not be treated in isolation from the motor and object manipulation skills conferred upon us by our physical bodies. A new model is needed in which inner computational processes are seen to co-operate with external (physical and social) structures to produce the phenomena of natural cognition. The scope of investigations required by such a model is examined, and suggestions made concerning its practical implications for workers in the field.
"Well, what do you think you understand with? With your head? Bah!" (Kazantzakis, 1959).
Cognitive science is heir to an unfortunate tradition. This tradition, firmly rooted in the philosophical doctrine of 'machine functionalism', asserts the independence of the study of mind from the details of its physical realization, or implementation, in a human body. We may call this the thesis of implementation neutrality. It is a thesis which one leading commentator in the field has described as "approaching the status of a dogma" (Boden, 1984). I wish to argue that this dogma has had its day. This is not to deny the well-established implementation-neutrality of particular algorithms; a single algorithm may be rendered in many programming languages and physically realized in many ways by different machines. But where 'cognitive content' is concerned, both the perceptual and motor capacities of the system in which implementation occurs are crucial. Indeed, so tight are the links between physical activity and cognitive content that it is fair to describe the physical and social environment, and our actions upon it, as part and parcel of the cognitive process itself. Cognitive science, if it is at all concerned with shedding light on human cognition, cannot afford to ignore the extended and active aspects of our thought. Implementation-neutrality, used as an excuse to investigate program structures in isolation from their role in an active human life, is thus a recipe for Z31 232 A. Clark distortion and omission. It is obviously tempting to hope for a circumscribed science of the mind. But politics aside, neatness is no substitute for truth.