 Again the area where this issue arose concerned proofs for the eternity of time. So, for example, in a novel proof for the existence of time based upon differences in the amount of distance that can be covered by slower and faster moving objects, Avicenna linked time with a possibility or capacity (imk7amacr;n) for motion (Avicenna 1985, 228–229). He then argued by means of a reducto ad absurdum. He has us assume that time is finite, and so the motion of the universe must have some first moment when it began. Even if the motion of the universe began at some first moment, the argument continues, clearly there would still have been the possibility for the Creator of the world to make a motion that extended further back. In that case, there is a capacity or possibility for motion that precedes the purported first moment, but time according to Avicenna is again just a certain capacity or possibility for motion. Thus a time would have preceded the purported first moment, which is absurd. Since the same argument applies to any purported first moment of time, concluded Avicenna, time can have no beginning and so must be infinite. Clearly, the conception of time implicit in Avicenna’s argument is that of a temporal line stretching back infinitely.