Consequently, motion always exists and what is moved always exists, and the whole wold. The now of time is always thought of as flowing, and it is in this that it differs from the now of eternity. But that which flows flows from something and into something. Therefore, every now must flow from a prior now and into a later now . Therefore, it is impossible that there be any first or last now .
Motion follows upon the movable thing, and time follows upon motion.
But the first movable thing, since it is circular, has neither a beginning nor an end. For in a circle there is no actual beginning or end. Therefore, neither does motion or time have a beginning. Same conclusion as above. The duration of a motion follows upon the measure of a magnitude.