Philosophy of Mind

What Are Mental States?

What makes a state the kind of mental state it is, such as a pain or a belief: its physical make-up, or the causal role it plays?

Positions

  1. Functionalism

    A mental state is what it is because of its causal role — its typical causes, its effects on other mental states, and its effects on behaviour — not because of what it is made of.

  2. Type Identity Theory

    Each type of mental state is identical with a type of brain state, a contingent identity discovered by science rather than by analysing what mental words mean.

Discussion

A pain, a belief, and a desire are different kinds of mental state, and this question asks what makes a state the kind it is. One answer looks to what the state is made of: pain is a particular kind of brain process. The other looks to what the state does: pain is whatever state is caused by injury and in turn causes distress and wincing, whatever it is made of. The two answers come apart for creatures built differently from us, such as an octopus, or a machine that might one day behave as if in pain.

This question differs from The Mind–Body Problem, which asks whether the mind is immaterial or entirely physical. An answer here need not settle that one: in principle, a causal role could be played by something non-physical.

References