Davidson on the Identity Theory

Abstract

Donald Davidson has advanced a novel argument for the psychophysical identity theory, the view that mental events are identical with physical events. Davidson contends that the truth of this theory can be inferred from three principles: (1) at least some mental events interact causally with physical events; (2) events related as cause and effect fall under strict deterministic laws; and (3) there can be no strict deterministic laws on the basis of which mental events can be predicted or explained (pp. 80–81).Davidson's contention is striking, quite aside from the question of whether (1), (2), and (3) are correct. For it is commonly assumed that discoveries in the empirical sciences—in particular, the discovery of psycho-physical laws—would be prerequisite for establishing a version of the identity theory. Davidson's argument is successful only if there can be no such discoveries: the third principle precludes the possibility of there being (strict) laws linking the mental and physical.