If to-morrow, to-day, and yesterday, as well as other similar divisions
of time, be parts of time, why should they not be classed in the same
classification as time itself, along with the ideas "it has been,"
"it is," and "it will be?" As they are kinds of time, it seems proper
that they should be classified along with time itself. Now time is
part of quantity. What then is the use of another category? If the
Aristotelians say that not only "it has been" and "it will be" are
time-concepts, but "yesterday" and "formerly," which are varieties
of "there has been" are also time-concepts (for these terms are
subordinated to "there has been"), that it is not only "now" that is
time, but that "when" is such also, they will be forced to answer as
follows: First, if "when" be time, time exists; then, as "yesterday"
is past time, it will be something composite, if the past be something
else than time; we will have to erect two categories, not merely a
simple category. For instance, they say both that "when" is in time,
without being time, and say that "when" is that which is in time. An
example of this would be to say that Socrates existed "formerly,"
whereby Socrates would really be outside of (present) time. Therefore
they are no longer expressing something single. But what is meant by
Socrates "being in time," and that some fact "is in time?" Does it mean
that they are "part of time?" If, in saying "a part of time," and "so
far as it is a part of time," the Aristotelians believe that they are
not speaking of time absolutely, but only of a past part of time, they
are really expressing several things. For this "part," so far as it is
a part, is by them referred to something; and for them the past will be
some thing added (to Time), or it will become identified with "there
has been," which is a kind of time. But if they say that there is a
difference, because "there has been" is indeterminate, while "formerly"
and "yesterday" are determinate, we shall be deciding something about
"there has been;" then "yesterday" will be the determination of "there
has been," so that "yesterday" will be determined time. Now, that
is a quantity of time; so that if time be a quantity, each one of
these two things will be a determined quantity. But, if, when they
say "yesterday" they mean thereby that such an event has happened in
a determined past time, they are still expressing several things.
Therefore, if some new category is to be introduced whenever one thing
acts in another, as here happened of what occurred in time, we might
have to introduce many additional categories, for in a different thing
the action is different. This will, besides, become clearer in what is
to follow on the category of place.