This is the text of The Lindley Lecture for 1962, given by Arthur N. Prior (1914-1969).

Since McTaggart first proposed his paradox asserting the unreality of time, numerous philosophers have attempted to defend the tensed theory of time against it. Certainly, one of the most highly developed and original is that put forth by Quentin Smith. Through discussing McTaggart's positive conception of time as well as his negative attack on its reality, I hope to clarify the dispute between those who believe in the existence of the transitory temporal properties of pastness, presentness and futurity, and those (...) who deny their existence. We shall see that the debate centers around the ontological status of succession and the B-relations of earlier and later. I shall argue that Smith's tensed theory fails because he cannot account for the sense in which events have their tensed properties successively, and he cannot account for the direction of time. (shrink)