What Is Time?

DR. CRAIG: What is time? Saint Augustine once said that, “If no one asks me, I know what time is. But if someone asks me, I'm unable to answer.” I think that the reason for the mysteriousness of time is that any attempt to reductively define time is going to sneak in temporal concepts so that you're talking in a circle. So, for example, if you say that time is a duration, well, what is duration? Well, duration is lasting through time! And so it's very, very difficult to offer any sort of a reductive definition of time. But I don't think that's a problem. I think with certain metaphysical concepts you after a while have to bottom out at bedrock, and that's simply where you stop. And so we can think of time, I think, as a dimension of reality that is ordered by this peculiar relation of “earlier than” and “later than,” and that distinguishes time from space. Space is related by relations like “before” and “after,” not in the temporal sense, but in the sense “in front of” and “behind.” But space has nothing analogous to the relationship of earlier than and later than, which orders the moments or intervals of time. So I think we can simply take that as our primitive and think of time as this dimension of reality in which we live that is ordered by this earlier than-later than relation.