and it therefore is not a cause at all. On the other hand, (b) Causation cannot be continuous. For this would mean that the cause was entirely without duration. It would never be itself except in the time occupied by a line drawn across the succession. And since this time is not a time, but a mere abstraction, the cause itself will be no better. It is unreal, a nonentity, and the whole succession of the world will consist of these nonentities. But this is much the same as to suppose that solid things are made of points and lines and surfaces. These may be fictions useful for some purposes, but still fictions they remain. The cause must be a real event, and yet there is no fragment of time in which it can be real. Causation is therefore not continuous; and so, unfortunately, it is not causation, but mere appearance.
The reader will understand at once that we have repeated here the old puzzle about time. Time, as we saw, must be made, and yet cannot be made, of pieces. And he perhaps will not be sorry to have reached an end of these pages through which I have been forced to weary him with continuity and discreteness. In the next chapter we shall arrive at somewhat different matter.
