t
there is a mid-time between two "nows" of time: hence they say that a
last "now" cannot be assigned in which it was in the term _wherefrom,_
just as in illumination, and in the substantial generation of fire,
there is no last instant to be assigned in which the air was dark, or
in which the matter was under the privation of the form of fire: but a
last time can be assigned, so that in the last instant of such time
there is light in the air, or the form of fire in the matter. And so
illumination and substantial generation are called instantaneous
movements.

But this does not hold good in the present case; and it is shown
thus. It is of the nature of rest that the subject in repose be not
otherwise disposed now than it was before: and therefore in every
"now" of time which measures rest, the subject reposing is in the
same "where" in the first, in the middle, and in the last "now." On
the other hand, it is of the very nature of movement for the subject
moved to be otherwise now than it was before: and therefore in every
"now" of time which measures movement, the movable subject is in
various dispositions; hence in the last "now" it must have a
different form from what it had before. So it is evident that to rest
during the whole time in some (disposition), for instance, in
whiteness, is to be in it in every instant of such time. Hence it is
not possible for anything to rest in one term during the whole of the
preceding time, and afterwards in the last instant of that time to be
in the other term. But this is possible in movement: because to be
moved in any whole time, is not to be in the same disposition in
every instant of that time. Therefore all instantaneous changes of
the kind are terms of a continuous movement: just as generation is
the term of the alteration of matter, and illumination is the term of
the local movement of the illuminating body. Now the local movement
of an angel is not the term of any other continuous movement, but is
of itself, depending upon no other movement. Consequently it is
impossible to say that he is in any place during the whole time, and
that in the last "now" he is in another place: but some "now" must be
assigned in which he was last in the preceding place. But where there
are many "nows" succeeding one another, there is necessarily time;
since time is nothing else than the reckoning of before and after in
movement. It remains, then, that the movement of an angel is in time.
It is