Abstract

There is a tension between the “growing block” account of time (closed past, open future) and the possibility of backwards time travel. If Tim the time traveler can someday travel backwards through time, then he has (in a certain sense) already been. He might discover this fact before (in another sense) he goes. Hence a dilemma: it seems that either Tim’s future is determined in an odd way or cases of (temporary) ontic indeterminate identity are possible. Either Tim cannot avoid heading for the past or he is only indeterminately that guy who appeared in the past with many of Tim’s memories. Determinacy in the past implies a degree of determinism in the future; indeterminism about the future seeps back to the past