Abstract

What are the vehicles of conceptual thought? Recently, cognitive scientists and philosophers of psychology have developed quite different theories about what kinds of representations concepts are. At one extreme, amodal theories claim that concepts are representations whose vehicles are distinct from those used in perceptual processes. At the other end of the spectrum, neo-empiricism proposes that concepts are perceptual representations grounded in the mind's sensory, motor, and affective systems. In this essay, I examine how evidence from the neuropsychological disorder semantic dementia bears on philosophical debates about the nature of conceptual vehicles. I argue that the pattern of deficits in semantic dementia undermines recent neo-empiricist predictions about where and how conceptual knowledge is organized in the brain. I do not intend my analysis of semantic dementia to wholly discredit neo-empiricism; instead, I draw lessons for future theorizing about conceptual vehicles