How Many Accounts of Act Individuation Are There?

The problem of act individuation is a debate about the identity conditions of human acts. The fundamental question about act individuation is: how do we distinguish between actions? Three views of act individuation have dominated the literature. First, Donald Davidson and G.E.M. Anscombe have argued that a number of different descriptions refer to a single act. Second, Alvin Goldman and Jaegwon Kim have argued that each description designates a distinct act. Finally, Irving Thalberg and Judith Jarvis Thomson have averred that some acts are sequences of causally related events, which include both a primitive bodily action and some of its effects. All of these accounts have assumed that a simple invariantist account of act individuation captures how ordinary people distinguish between acts. For my dissertation, I devised an experiment to test the action theorists' assumptions. My data show that people's intuitions seem to depend on the valence of the consequences of the action under consideration. So, an invariantist account is not possible. In light of the empirical results, I argue that if we seek a folk account of act individuation, then that account should be able to explain the variability that seems to be present in people's intuitions about different cases.