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. 5. WHERE, OR, PLACE. IF "WHERE" AND "PLACE" ARE DIFFERENT CATEGORIES, MANY MORE MIGHT BE ADDED.