7. (8). Time cannot (as the Stoics claim,[447]) be movement. Neither
can we gather together all movements, so as to form but a single one,
nor can we consider the regular movement only; for these two kinds of
motion are within time. If we were to suppose that there was a movement
that did not operate within time, such a movement would still be far
removed from being time, since, under this hypothesis, the movement
itself is entirely different from that in which the movement occurs.
Amidst the many reasons which, in past and present, have been advanced
to refute this opinion, a single one suffices: namely, that movement
can cease and stop, while time never suspends its flight. To the
objection that the movement of the universe never stops, we may answer
that this movement, if it consist in the circular movement (of the
stars, according to Hestius of Perinthus; or of the sun, according to
Eratosthenes[447]) operates within a definite time, at the end of which
it returns to the same point of the heavens, but it does not accomplish
this within the same space of time taken up in fulfilling the half of
its course. One of these movements is only half of the other, and the
second is double. Besides, both, the one that runs through half of
space, and the one that runs through the whole of it, are movements of
the universe. Besides, it has been noticed that the movement of the
exterior sphere is the swiftest. This distinction supports our view,
for it implies that the movement of this sphere, and the time used to
operate it, are different entities; the most rapid movement is the one
that takes up the least time, and runs through the greatest amount of
space; the slowest movements are those that employ the longest time,
and run through only a part of that space.[448]