Abstract

Donald Davidson espouses two fundamental theses about the individuation of mental events. The thesis of causal individuation asserts that sameness of cause and effect is sufficient and necessary for event identity. The thesis of content individuation gives only a sufficient condition for difference of mental events: if e and f have different contents then they are different mental events. I argue that given these theses, psychological externalism--the view that mental content is determined by factors external to the subject of the relevant mental events--entails that the token identity theory is false