ABSTRACT
This chapter examines formulation of functionalism, in terms of "causal role". Central to any version of functionalism is the idea that a mental state can be characterized in terms of the input-output relations it causally mediates, where the inputs and outputs may include other mental states as well as sensory stimuli and physical behaviors. Mental phenomena are conceived as nodes in a complex causal network that engages in causal transactions with the outside world at its peripheries, by receiving sensory inputs and emitting behavior outputs. The chapter shows how to generate more realistic functional definitions of psychological concepts by the Ramsey-Lewis method. The antiphysicalist might argue that psychological capacities and mechanisms have their own separate, nonphysical reality. The chapter reviews the issue of qualia in connection with the more general questions about consciousness. The functionalist claim is often expressed by assertions like "Mental states are causal roles" and "Mental properties are functional properties".
