Abstract: Work on concepts has concentrated on categorization. Categorization is a process that starts with perceptual representations and other special-purpose resources, transitioning from these to a conceptual representation. Just as important, however, are inferences that, rather than being driven by current stimuli, start with a conceptual representation. We engage in ‘offline’ thinking to formulate plans and take decisions, as well as to derive consequences from facts that we remember and episodes that we have experienced. The usual paradigm for conceptually-driven thinking is reasoning. In reasoning we move from some concept-involving thoughts to others. Reasoning deploys a general-purpose computational process, rather like theorem-proving in logic, and uses the general-purpose representational system of conceptual thought.
Often overlooked between these two paradigms is the way that offline processing, driven by concepts, draws on special-purpose resources. These resources can be sensory, motoric, affective, evaluative or supra-modal (e.g. a spatial map). The phenomenon itself is familiar: we imagine a situation or think through a counterfactual scenario using representations from special-purpose systems. What is under-theorised is how suppositional thinking driven by conceptual representations actually works. This paper offers an empirically-based model of the process. Concepts act as an interface, allowing concept-driven thinking to draw on representational structures of various different kinds, and to rely on computational processes of two distinct types. It seems that concepts furnish us with a general-purpose ability to use special-purpose resources. That is the basis of the distinctive power of conceptual thought.