Functionalism
Mental states are characterized by their causal roles.
What it claims
Functionalism identifies a mental state by what it does within a system: its relations to sensory inputs, other mental states, and behavioral outputs. What makes a state pain or belief is its role rather than one particular material composition. Putnam's multiple-realizability argument (1967) challenges a single neural-type identification: beings with very different nervous systems could still feel pain.
Nearby positions
Goes together with
Key thinkers
Hilary Putnam · David Lewis · Jerry Fodor · Daniel Dennett