時制の区分は変化しうるか

Abstract

Contemporary metaphysics of time has two main theories: A-theory and B-theory. A-theory claims that the distinction between past, present and future is objective, while B-theory denies this. This debate is often considered to be a dispute over the reality of passage of time. The notion of passage is typically defined as a change of A-properties (pastness, presentness and futurity). Thus, A-theory is seen as defending our ordinary belief that time passes, while B-theory claims that the passage of time is not real. In this paper, I aim to raise some doubts about the possibility of change of A-properties. In his classic article, ‘The Unreality of Time’, McTaggart argued that if the A-properties are ascribed to events, a contradiction arises, so the distinction between past, present and future cannot be real. The contradiction, he argues, follows from the fact that events must have three A-properties, although they are incompatible. A-theorists, who advocate the objectivity of the distinction, have attempted to refute his argument and prove that the contradiction does not arise. I neither intend to provide a defense of McTaggart nor further support for a counterargument by the A-theorists. Through the examination of this debate, I will show that the idea of changes of A-properties contains principles that cannot be coherently combined together. My discussion itself neither argues for nor against the reality of passage, but rather suggests the necessity of finding a new way of thinking about the passage of time.