DURATION.
Time and duration are usually considered synonymous, as no duration is perceived by us, except the duration of movement, or of such things as are subject to movement; and such duration is time. But, rigorously speaking, time and duration are not synonymous; for they are to one another in the same relation as place and space. As no place is possible without real absolute space, so no time is possible without real absolute duration; and as place consists of intervals in space, so time consists of intervals in duration. Yet there may be duration independently of time, just as there may be space independent of places; and for this reason the nature of duration must be determined apart from the nature of time. In treating of this subject we shall have to answer a series of questions altogether similar to those which we have answered in treating of space and place. Hence we shall follow the same order and method in our present treatise which we have followed in our articles on space, with this difference, however: that, to avoid useless repetitions, we will omit the development of some of those reasonings which the reader himself can easily transfer from space to duration.
Duration is commonly defined as “the permanence of a being in its actuality”—Permanentia rei in esse. The duration of a being which perseveres in existence without any intrinsic change is called “standing duration”—Duratio stans. The duration of a being which is actually subject to intrinsic mutations is called “flowing duration”—Duratio fluens.
Flowing duration evidently implies succession, and succession involves time; for succession is a relation between something which follows and something which precedes. On the other hand, time also involves succession; whence it would seem that neither time nor succession can be defined apart from one another, the definition of the latter presupposing that of the former, and that of the former presupposing the notion of the latter. Although we need not be anxious about this point (for time and succession really involve one another, and therefore may well be included under the same definition), we must observe that the notion of succession, though ordinarily applied to duration, extends to other things also whenever they follow one another in a certain order. Thus the crust of the earth is formed by a succession of strata, the Alps by a succession of mountains, the streets of the city by a succession of houses, etc. Hence the notion of succession is more general than the notion of time, and consequently there must be some means of defining it independently of the consideration of time.
Balmes explains succession, without mentioning time, in the following manner: “There are things which exclude one another from the same subject, and there are other things which do not exclude one another from the same subject. The existence of those things which exclude one another implies succession. Take a line ABC. A body placed in A cannot pass over to the place B without ceasing to be in A, because the situation B excludes the situation A, and in a similar manner the situation C excludes the situation B. If, then, notwithstanding this mutual exclusion, the three places are really occupied by the same body, there is succession. This shows that succession is really nothing else than the existence of such things as exclude one another. Hence succession implies the existence of the thing that excludes, and the non-existence of the things that are excluded. All variations involve some such exclusion; hence all variations involve succession.… To perceive the existence of things which exclude one another is to perceive succession and time; to measure it is to measure time.” Thus far Balmes.[10]
But, if the flowing duration can be easily conceived as the existence of such things as exclude one another, the case is very different with regard to standing duration. For, since we measure all duration by time or by successive intervals, we can scarcely conceive that there may be duration without succession. Even the word “permanence” which we employ in the definition of duration, and which seems to exclude all notion of change, is always associated in our thought with succession and time. The difficulty we experience in forming a concept of standing duration is as great at least as that which we find in conceiving absolute space without formal extension and parts. In fact, formal extension is to absolute space what formal succession is to absolute standing duration. To get over this difficulty we shall have to show that there is a duration altogether independent of contingent changes, as there is a space altogether independent of existing bodies, and that the succession which we observe in the duration of created things is not to be found in the fundamental reason of its existence, as our imagination suggests, but only in the changes themselves which we witness in created things.
The following questions are to be answered: Is there any standing duration? and if so, is it an objective reality, or a mere negation of movement? Is standing duration anything created? What sort of reality is it? Is it modified by the existence of creatures? What is a term of duration? What is relative duration? What is an interval of duration, and how is it measured? These questions are all parallel to those which we have answered in our first and second articles on space, and they admit of a similar solution.
First question.—“Is there any duration absolutely standing?” Certainly. For if there is a being whose entity remains always the same without any intrinsic change, its duration will be absolutely standing. But there is such a being. For there is, as we have proved, an infinite reality absolutely immovable and unchangeable—that is, absolute space. Its permanence is therefore altogether exempt from succession; and consequently its duration is absolutely standing.