"I tend to be always thinking of time, not of space. When I hear the words "time" and "space" used together, I feel as Nietzsche felt when he heard people talking about Goethe and Schiller—a kind of blasphemy. I think that the central riddle, the central problem of metaphysics—let us call it thinking—is time, not space. Space is one of the many things to be found inside of time—as you find, for example, color or shapes or sizes or feelings. But I think the real problem, the problem we have to grapple with, and of course the problem whose solution we'll never find, is the problem of time, of sucessive time, and, therein, the problem of personal identity, which is but part of the problem of time"
Conversations, Jorge Luis Borges