Abstract

Kant saw in an old argument a threat to his criticism of traditional rational psychology. He called this argument the Achilles of all dialectical inferences. What the Achilles purports to prove is that the unity of consciousness requires the simplicity of the soul. The argument proceeds from, a distinction between two types ofactions that are ascribable to a subject. For example, when we say that a school of fish moves, this movement can be explained by referring to the movements of the fish constituting that whole. Thus, “moving” is an action type that can be attributed to an aggregate. The second premise says that the action of the thinking I cannot be regarded as the concurrence of several things acting. Thus, any thinking self has to be a simple subject because the action of the thinking self cannot be an aggregate of several actions of different subjects constituting that self. In this paper, Kant’s criticism of the Achilles argument is investigated.