Indeed, as it was not possible to determine the time itself of the
Soul, and to measure within themselves the parts of an invisible and
uncognizable duration, especially for men who did not know how to
count, the (world) Soul created day and night so that their succession
might be the basis of counting as far as two, by the aid of this
variety. Plato[464] indicates that as the source of the notion of
number. Later, observing the space of time which elapses from one dawn
to another, we were able to discover an interval of time determined by
an uniform movement, so far as we direct our gaze thereupon, and as
we use it as a measure by which to measure time. The expression "to
measure time" is premeditated, because time, considered in itself, is
not a measure. How indeed could time measure, and what would time,
while measuring, say? Would time say of anything, "Here is an extension
as large as myself?" What indeed could be the nature of the entity that
would speak of "myself"? Would it be that according to which quantity
is measured? In this case, time would have to be something by itself,
to measure without itself being a measure. The movement of the universe
is measured according to time, but it is not the nature of time to be
the measure of movement; it is such only accidentally; it indicates
the quantity of movement, because it is prior to it, and differs from
it. On the other hand, in the case of a movement produced within a
determinate time, and if a number be added thereto frequently enough,
we succeed in reaching the knowledge of how much time has elapsed.
It is therefore correct to say that the movement of the revolution
operated by the universal Sphere measures time so far as possible, by
its quantity indicating the corresponding quantity of time, since it
can neither be grasped nor conceived otherwise. Thus what is measured,
that is, what is indicated by the revolution of the universal Sphere,
is time. It is not begotten, but only indicated by movement.
MOVEMENT IS SAID TO BE MEASURED BY SPACE, BECAUSE OF ITS
INDETERMINATION.
The measure of movement, therefore, seems to be what is measured by
a definite movement, but which is other than this movement. There is
a difference, indeed, between that which is measured, and that which
measures; but that which is measured is measured only by accident.
That would amount to saying that what is measured by a foot-rule is
an extension, without defining what extension in itself is. In the
same way, because of the inability to define movement more clearly
because of its indeterminate nature, we say that movement is that which
is measured by space; for, by observation of the space traversed by
movement, we can judge of the quantity of the movement.
TIME IS MEASURED BY MOVEMENT, AND IN THAT SENSE IT IS THE MEASURE OF
MOVEMENT.
12. (13). The revolution of the universal Sphere leads us therefore to
the recognition of time, within which it occurs. Not only is time that
in which (all things "become," that is, grow), but time has to be what
it is even before all things, being that within which everything moves,
or rests with order and uniformity. This is discovered and manifested
to our intelligence, but not produced by regular movement and rest,
especially by movement. Better than rest, indeed, does movement lead us
to a conception of time, and it is either to appreciate the duration
of movement than that of rest. That is what led philosophers to define
time as the measure "of" movement, instead of saying, what probably
lay within their intention, that time is measured "by" movement. Above
all, we must not consider that definition as adequate, adding to it
that which the measured entity is in itself, not limiting ourselves
to express what applies to it only incidentally. Neither did we ever
discern that such was their meaning, and we were unable to understand
their teachings as they evidently posited the measure in the measured
entity. No doubt that which hindered us from understanding them was
that they were addressing their teachings to learned (thinkers), or
well prepared listeners, and therefore, in their writings, they failed
to explain the nature of time considered in itself, whether it be
measure or something measured.