Intellectually, we may reject Cartesian Dualism, but dualism often dominates our everyday thinking: we talk of “mental” illness as though it were non-physical; we tend to blame people for the symptoms of brain malfunctions in a way that differs from how we treat other illnesses. An examination of current theories of mind will reveal that some form of dualism is not always limited to the non-scientific realm. While very few, if any, cognitive scientists support mind-body dualism, those who support the view of the mind as a symbol-manipulator are often constrained to postulate more than one cognitive system in response to the failure of the symbol-system model to account for all aspects of human cognition.

In this dissertation, I argue for an empiricist, rather than a realist, theory of perception, for an internalist semantics, and for a model of cognitive architecture which combines a connectionist approach with highly-specialized, symbolic, computational component which  includes functions that provide input to a a causally-inert conscious mind. I reject the symbol-system hypothesis and propose a cognitive architecture which, I contend, is biologically-plausible and more consistent with the results of recent neuroscientific studies. This hybrid model can accommodate the processes commonly discussed by dual-process theorists and can also accommodate the processes which have proved to be so problematic for models based on the symbol-system hypothesis.