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.
Again: As there is no movement in space without immovable space, so there is no flowing in duration without standing duration. For as a thing cannot change its ubication in space unless there be a field for real ubications between the initial and the final term of the movement, so a thing cannot change its mode of being (the when) in duration, unless there be a field for real modes of being between the initial and the final term of its duration. Now, this real field, owing to the fact that it is, in both cases, prerequired for the possibility of the respective changes, is something necessarily anterior to, and independent of, any of such changes. Therefore, as the field of all local movements is anterior to all movements and excludes movement from itself, so also the field of all successive durations is anterior to all successivity and therefore excludes succession.
Although these two arguments suffice to establish our conclusion, what we have to say concerning the next question will furnish additional evidence in its support.
Second question.—“Is standing duration an objective reality or a mere abstract conception?” We answer that standing duration is an objective reality as much as absolute space. For, as movement cannot extend in space, if space is nothing real, so movement cannot extend in duration, if the field of its extension is nothing real. But we have just seen that the field through which the duration of movement extends is standing duration. Therefore standing duration is an objective reality.
Secondly, a mere nothing, or a mere fiction, cannot be the foundation of real relations. But standing duration is the foundation of all intervals of real succession, which are real relations. Therefore standing duration is not a fiction, but an objective reality. The major of this argument is well known. The minor is proved thus: In all real relations the terms must communicate with each other through one and the same reality; and therefore the foundation of a real relation must reach by one and the same reality the terms related. But the terms of successive duration are before and after. Therefore the foundation of their relation must reach both before and after with one and the same reality, and therefore it has neither before nor after in itself. Had it before and after in itself, its after would not be its before; and thus the reality by which it would reach the terms of succession would not be the same. It is therefore manifest that the foundation of all real intervals of succession is a reality whose duration ranges above succession.
This proof may be presented more concisely as follows: Succession is a relation between two terms, as past and present. Its foundation must therefore reach all the past as it reaches the present. But what reaches the past as well as the present, is always present; for if it were past, it would be no more, and thus it could not reach the past and the present. Therefore the foundation of succession has no past, but only an invariable present. Therefore there is a real standing duration, a real field, over which successive duration extends.
Thirdly, in all intervals of succession the before is connected with the after through real duration. But this real duration has in itself neither before nor after. For if it had before and after, it would fall under the very genus of relation of which it is the foundation; which is evidently impossible, because it would then be the foundation of its own entity. It is therefore plain that the real connection between the before and the after is made by a reality which transcends all before and all after, and which is nothing else than absolute standing duration.
Fourthly, if standing duration were not an objective reality, but a mere fiction or a mere negation of movement, there would be no real length of duration. For the terms of successive duration are indivisible, and consequently they cannot give rise to any continuous quantity of duration, unless something lies between them which affords a real ground for continuous extension. That the terms of successive duration are indivisible is evident, because the same term cannot be before itself nor after itself, but is wholly confined to an indivisible instant. Now, that according to which an interval of successive duration can be extended from one of these terms to another, is nothing but absolute and standing duration. For, if it were flowing, it would pass away with the passing terms, and thus it would not lie between them, as is necessary in order to supply a ground for the extension of the interval intercepted. In the same manner, therefore, as there cannot be distance between two ubicated points without real absolute space, there cannot be an interval between two terms in succession without real absolute duration.
A fifth proof of the same truth may be drawn from the reality of the past. Historical facts are real facts, although they are all past. There really was a man called Solomon, who really reigned in Jerusalem; there really was a philosopher called Plato, whose sublime doctrines deserved for him the surname of Divine; there really was a man called Attila, surnamed the Scourge of God. These men existed in different intervals of duration, and they are no more; but their past existence and their distinct duration constitute three distinct facts, which are real facts even to the present day, and such will remain for ever. Now, how can we admit that what has wholly ceased to exist in successive duration is still a real and indelible fact, unless we admit that there is an absolute duration which is, even now, as truly united with the past as it is with the present, and to which the past is not past, but perpetually present? If there is no such duration, then all the past must have been obliterated and buried in absolute nothingness; for if the succession of past things extended upon itself alone, without any distinct ground upon which its flowing could be registered, none of past things could have left behind a real mark of their existence.
Against this conclusion some will object that the relation between before and after may be explained by a mere negation of simultaneous existence. But the objection is futile. For the intervals of successive duration can be greater or less, whilst no negation can be greater or less; which shows that the negation of simultaneous existence must not be confounded with the intervals of succession.
The following objection is more plausible. The duration of movement suffices to fill up the whole interval of succession and to measure its extent; and therefore the reality which connects the before with the after is movement itself, not standing duration. To this we answer that the duration of movement is essentially successive and relative; and therefore it requires a real foundation in something standing and absolute. In fact, although every movement formally extends and measures its own duration, nevertheless it does not extend it upon itself, but upon a field extrinsic to itself; and this field is permanently the same. It is plain that the beginning and the end of movement cannot be connected in mutual relation through movement alone, because movement is always in fieri, and when it passes through one term of its duration it loses the actuality it had in the preceding term; so that, when it reaches its last term, it has nothing left of what it possessed in its initial term or in any other subsequent term. This suffices to show that, although the duration of the movement fills up the whole interval, yet, owing to its very successivity, it cannot be assumed as the ground of the relation intervening between its successive terms.
Third question.—“Is absolute and standing duration a created or an uncreated reality?” This question is easily answered; for, in the first place, standing duration is the duration of a being altogether unchangeable; and nothing unchangeable is created. Hence standing duration is an uncreated reality. On the other hand, all that is created is changeable and constantly subject to movement; hence all created (that is, contingent) duration implies succession. Therefore standing duration is not to be found among created realities. Lastly, standing duration, as involving in itself all conceivable past and all possible future, is infinite, and, as forming the ground of all contingent actualities, is nothing less than the formal possibility of infinite terms of real successive duration. But such a possibility can be found in God alone. Therefore the reality of standing duration is in God alone; and we need not add that it must be uncreated.
Fourth question.—“What reality, then, is absolute standing duration?” We answer that this duration is the infinite virtuality or extrinsic terminability of God’s eternity. For nowhere but in God’s eternity can we find the reason of the possibility of infinite terms and intervals of duration. Of course, God’s eternity, considered absolutely ad intra, is nothing else than the immobility of God’s existence; but its virtual comprehension of all possible terms of successive duration constitutes the absolute duration of God’s existence, inasmuch as the word “duration” expresses a virtual extent corresponding to all possible contingent duration; for God’s duration, though formally simultaneous, virtually extends beyond all imaginable terms and intervals of contingent duration. Hence standing duration is the duration of God’s eternity, the first and fundamental ground of flowing duration, the infinite range through which the duration of changeable things extend. In other words, the infinite virtuality of God’s eternity, as equivalent to an infinite length of time, is duration; and as excluding from itself all intrinsic change, is standing duration. This virtuality of God’s eternity is really nothing else than its extrinsic terminability; for eternity is conceived to correspond to all possible differences of time only inasmuch as it can be compared with the contingent terms by which it can be extrinsically terminated.
Secondly, if nothing had been created, there would have been no extrinsic terms capable of extending successive duration; but, since God would have remained in his eternity, there would have remained the reality in which all extrinsic terms of duration have their virtual being; and thus there would have remained, eminently and without formal succession, in God himself the duration of all the beings possible outside of God. For he would certainly not have ceased to exist in all the instants of duration in which creatures have existed; the only change would have been this: that those instants, owing to a total absence of creatures, would have lacked their formal denomination of instants, and their formal successivity. Hence, if nothing had been created, there would have remained infinite real duration without succession, simply because the virtuality of God’s eternity would have remained in all its perfection. It is therefore this virtuality that formally constitutes standing duration.
From this the reader will easily understand that in the concept of standing duration two notions are involved, viz.: that of eternity, as expressing the standing, and that of its virtuality, as connoting virtual extent. In fact, God’s eternity, absolutely considered, is simply the actuality of God’s substance, and, as such, does not connote duration; for God’s substance is not said to endure, but simply to be. The formal reason of duration is derived from the extrinsic terminability of God’s eternity; for the word “duration” conveys the idea of continuation, and continuation implies succession. Hence it is on account of its extrinsic terminability to successive terms of duration that God’s eternity is conceived as equivalent to infinite succession; for what virtually contains in itself all possible terms and intervals of succession virtually contains in itself all succession, and can co exist, without intrinsic change, with all the changes of contingent duration. Balmes, after defining succession as the existence of such things as exclude one another, very properly remarks: “If there were a being which neither excluded any other being nor were excluded by any of them, that being would co-exist with all beings. Now, one such being exists, viz.: God, and God alone. Hence theologians do but express a great and profound truth when they say (though not all, perhaps, fully understand what they say) that God is present to all times; that to him there is no succession, no before or after; that to him everything is present, is Now.”[11]
We conclude that standing duration is infinite, all-simultaneous, independent of all contingent things, indivisible, immovable, formally simple and unextended, but equivalent to infinite intervals of successive duration, and virtually extending through infinite lengths. This duration is absolute.
Fifth question.—“Does the creation of a contingent being in absolute duration cause any intrinsic change in standing duration?” The answer is not doubtful; for we have already seen that standing duration is incapable of intrinsic modifications. Nevertheless, it will not be superfluous to remark, for the better understanding of this answer, that the “when” (the quando) of a contingent being has the same relation to the virtuality of God’s eternity as has its “where” (the ubi) to the virtuality of God’s immensity. For, as the “where” of every possible creature is virtually precontained in absolute space, so is the “when” of all creatures virtually precontained in absolute duration. Hence the creation of any number of contingent beings in duration implies nothing but the extrinsic termination of absolute duration, which accordingly remains altogether unaffected by the existence in it of any number of extrinsic terms. The “when” of a contingent being, as contained in absolute duration, is virtual; it does not become formal except in the contingent being itself—that is, by extrinsic termination. Thus the subject of the contingent “when” is not the virtuality of God’s eternity any more than the subject of the contingent “where” is the virtuality of God’s immensity.
This shows that the formal “when” of a contingent being is a mere relativity, or a respectus. The formal reason, or the foundation, of this relativity is the reality through which the contingent being communicates with absolute standing duration, viz.: the real instant (quando) which is common to both, although not in the same manner; for it is virtual in standing duration, whilst it is formal in the extrinsic term. Hence a contingent being, inasmuch as it has existence in standing duration, is nothing but a term related by its “when” to divine eternity as existing in a more perfect manner in the same “when.” But, since the contingent “when” of the creature exclusively belongs to the creature itself, God’s standing duration receives nothing from it except a relative extrinsic denomination.
The relation resulting from the existence of a created term in standing duration consists in this: that the created term by its formal “when” really imitates the eminent mode of being of God himself in the same “when.” This relation is called simultaneousness.
Simultaneousness is often confounded with presence and with co-existence. But these three notions, rigorously speaking, differ from one another. Presence refers to terms in space; simultaneousness to terms in duration; co-existence to terms both present and simultaneous. Thus presence and simultaneousness are the constituents of co-existence. Presence is to be considered as the material constituent, because it depends on the “where,” which belongs to the thing on account of its matter or potency; simultaneousness must be considered as the formal constituent, because it depends on the “when,” which belongs to the thing on account of its act or of its resulting actuality.
Before we proceed further, we must yet remark that in the same manner as the infinite virtuality of divine immensity receives distinct extrinsic denominations from the contingent terms existing in space, and is thus said to imply distinct virtualities, so also the infinite virtuality of God’s eternity can be said to imply distinct virtualities, owing to the distinct denominations it receives from distinct terms of contingent duration. It is for this reason that we can speak of virtualities of eternity in the plural. Thus when we point out the first instant of any movement as distinct from any following instant, we consider the flowing of the contingent “when” from before to after as a passage from one to another virtuality of standing duration. These virtualities, however, are not distinct as to their absolute beings, but only as to their extrinsic termination and denomination; and therefore they are really but one infinite virtuality. As all that we have said of the virtualities of absolute space in one of our past articles equally applies to the virtualities of absolute duration, we need not dwell here any longer on this point.
Sixth question.—“In what does the ‘when’ of a contingent being precisely consist?” From the preceding considerations it is evident that the “when” of a contingent being may be understood in two manners, viz., either objectively or subjectively. Objectively considered, the “when” is nothing else than a simple and indivisible term in duration formally marked out in it by the actuality of the contingent being. We say a simple and indivisible term, because the actuality of the contingent being by which it is determined involves neither past nor future, neither before nor after, but only its present existence, which, as such, is confined to an indivisible Now. Hence we do not agree with those philosophers who confound the quando with the tempus—that is, the “when” with the extent of flowing duration. We admit with these philosophers that the “when” of contingent things extends through movement from before to after, and draws, so to say, a continuous line in duration; but we must remind them that the before and the after are distinct modes of being in duration, and that every term of duration designable between them is a distinct “when” independent of every other “when,” either preceding or following; which shows that the tempus implies an uninterrupted series of distinct “whens,” and therefore cannot be considered as synonymous with quando.
If the “when” is considered subjectively—that is, as an appurtenance of the subject of which it is predicated—it may be defined as the mode of being of a contingent thing in duration. This mode consists of a mere relativity; for it results from the extrinsic termination of absolute duration, as already explained. Hence the “when” is not received in the subject of which it is predicated, and does not inhere in it, but, like all other relativities and connotations, simply connects it with its correlative, and intervenes or lies between the one and the other.
But, although it consists of a mere relativity, the “when” still admits of being divided into absolute and relative, according as it is conceived absolutely as something real in nature, or compared with some other “when”; for, as we have already explained when treating of ubications, relative entities may be considered both as to what they are in themselves, and as to what they are to one another.
If the “when” is considered simply as a termination of standing duration, without regard for anything else, it is called absolute, and is defined as the mode of being of a thing in absolute duration. This absolute “when” is an essential mode of the contingent being no less than its dependence from the first cause, and is altogether immutable so long as the contingent being exists; for, on the one hand, the contingent being cannot exist but within the domain of divine eternity, and, on the other, it cannot have different modes of being with regard to it, as the standing duration of eternity is all uniform in its infinite virtual extension, and the contingent being, however much we may try to vary its place in duration, must always be in the very middle of eternity. Hence the absolute “when” is altogether unchangeable.
If the “when” of a contingent being is compared with that of another contingent being in order to ascertain their mutual relation, then the “when” is called relative, and, as such, it may be defined as the mode of terminating a relation in duration. This “when” is changeable, not in its intrinsic entity, but in its relative formality; and it is only under this formality that the “when” (quando) can be ranked among the predicamental accidents; for this changeable formality is the only thing in it which bears the stamp of an accidental entity.
The before and the after of the same contingent being are considered as two distinct relative terms, because the being to which they refer, when existing in the after, excludes the before; though the absolute “when” of one and the same being is one term only. But of this we shall treat more fully in the sequel.
Seventh question.—“What is relative duration?” Here we meet again the same difficulty which we have encountered in explaining relative space; for in the same manner as relations in space are usually confounded with space itself, so are the intervals in duration confounded with the duration which is the ground of their extension. But, as the reasonings by which we have established the precise notion of relative space can be easily brought to bear on the present subject by the reader himself, we think we must confine ourselves to a brief and clear statement of the conclusions drawn from those reasonings, as applied to duration.
Relative duration is the duration through which any movement extends; that is, the duration through which the “when” of anything in movement glides from before to after, and by which the before and the after are linked in mutual relation. Now, the duration through which movement extends is not exactly the duration of the movement itself, but the ground upon which the movement extends its own duration; because movement has nothing actual but a flowing instant, and therefore it has no duration within itself except by reference to an extrinsic ground through which it successively extends. This ground, as we have already shown, is standing duration. And therefore relative duration is nothing else than standing duration as extrinsically terminated by distinct terms, or, what amounts to the same terminated by one term which, owing to any kind of movement, acquires distinct and opposite formalities. This conclusion is based on the principle that the foundation of all relations between before and after must be something absolute, having in itself neither before nor after, and therefore absolutely standing. This principle is obviously true. The popular notion, on the contrary, that relative duration is the duration of movement, is based on the assumption that movement itself engenders duration—which assumption is false; for we cannot even conceive movement without presupposing the absolute duration upon which the movement has to trace the line of its flowing existence.
Thus relative duration is called relative, not because it is itself related, but because it is the ground through which the extrinsic terms are related. It is actively, not passively, relative; it is the ratio, not the rationatum, the foundation, not the result, of the relativities. In other terms, relative duration is absolute as to its entity, and relative as to the extrinsic denomination derived from the relations of which it is the formal reason. Duration, as absolute, may be styled “the region of all possible whens,” just as absolute space is styled “the region of all possible ubications”; and, as relative, it may be styled “the region of all possible succession,” just as relative space is styled “the region of all local movements.” Absolute standing duration and absolute space are the ground of the here and now as statical terms. Relative standing duration and relative space are the ground of the here and now as gliding—that is, as dynamically considered.
Eighth question.—“What is an interval of duration?” It is a relation existing between two opposite terms of succession—that is, between before and after. An interval of duration is commonly considered as a continuous extension; yet it is primarily a simple relation by which the extension of the flowing from before to after is formally determined. Nevertheless, since the “when” cannot acquire the opposite formalities, before and after, without continuous movement, all interval of duration implies movement, and therefore may be considered also as a continuous quantity. Under this last aspect, the interval of duration is nothing else than the duration of the movement from before to after.
We have already noticed that the duration of movement, or the interval of duration, is not to be confounded with the duration through which the movement extends. But as, in the popular language, the one as well as the other is termed “relative duration,” we would suggest that the duration through which the movement extends might be called fundamental relative duration, whilst the relation which constitutes an interval between before and after might be called resultant relative duration.
The philosophical necessity of this distinction is obvious, first, because the standing duration, through which movement extends, must not be confounded with the flowing duration of movement; secondly, because the relation and its foundation are not the same thing, and, as we have explained at length when treating of relative space, to confound the one with the other leads to Pantheism. Intervals of relation are not parts of absolute duration, though they are so conceived by many, but they are mere relations, as we have stated. Absolute duration is all standing, it has no parts, and it cannot be divided into parts. What is called an interval of duration should rather be called an interval in duration; for it is not a portion of standing duration, but an extrinsic result; it is not a length of absolute duration, but the length of the movement extending through that duration; it is not a divisible extension, but the ground on which movement acquires its divisible extension from before to after. In the smallest conceivable interval of duration there is God, with all his eternity. To affirm that intervals of duration are distinct durations would be to cut God’s eternity to pieces by giving it a distinct being in really distinct intervals. Hence it is necessary to concede that, whilst the intervals are distinct, the duration on which they have their foundation is one and the same. The only duration which can be safely confounded with those intervals is the flowing duration of the movement by which they are measured. This is the duration which can be considered as a continuous quantity divisible into parts; and this is the duration which we should style “resultant relative duration,” to avoid all danger of error or equivocation.
The objections which can be made against this manner of viewing things do not much differ from those which we have solved in our second article on space; and therefore we do not think it necessary to make a new answer to them. The reader himself will be able to see what the objections are, and how they can be solved, by simply substituting the words “eternity,” “duration,” etc., for the words “immensity,” “space,” etc., in the article referred to.
Yet a special objection can be made against the preceding doctrine about the duration of movement, independently of those which regard relations in space. It may be presented under this form. “The foundation of the relation between before and after is nothing else than movement itself. It is therefore unnecessary and unphilosophical to trace the duration of movement to the virtuality of God’s eternity as its extrinsic foundation.” The antecedent of this argument may be proved thus: “That thing is the foundation of the relation which gives to its terms their relative being—that is, in our case, their opposite formalities, before and after. But movement alone gives to the when these opposite formalities. Therefore movement alone is the foundation of successive duration.”
We answer that the antecedent of the first argument is absolutely false. As to the syllogism which comes next, we concede the major, but we deny the minor. For it is plain that movement cannot give to the absolute when the relative formalities before and after, except by flowing through absolute duration, without which it is impossible for the movement to have its successive duration. And surely, if the movement has no duration but that which it borrows from the absolute duration through which it extends, the foundation of its duration from before to after can be nothing else than the same absolute duration through which the movement acquires its before and after. Now, this absolute duration is the virtuality of God’s eternity, as we have proved. It is therefore both philosophical and necessary to trace the duration of movement to the virtuality of God’s eternity, as its extrinsic foundation. That movement is also necessary to constitute the relation between before and after, we fully admit; for there cannot be before and after without movement. But it does not follow from this that movement is the foundation of the relation; it merely follows that movement is a condition necessary to give to the absolute when two distinct actualities, according to which it may be compared with itself on the ground of standing duration. For, as every relation demands two opposite terms, the same absolute when must acquire two opposite formalities, that it may be related to itself.
The only other objection which may perhaps be made against our conclusions is the following: The foundation of a real relation is that reality through which the terms related communicate with one another. Now, evidently, the before and the after, which are the terms of the relation in question, communicate with one another through the same absolute when; for they are the same absolute when under two opposite formalities. Hence it follows that the foundation of the relation between before and after is nothing else than the absolute when of a moving being.
To this we answer that the foundation of the relation is not all reality through which the terms related communicate with one another, but only that reality by the common termination of which they become formally related to one another. Hence, since the before and the after do not receive their relative formalities from the absolute when, it is idle to pretend that the absolute when is the foundation of the interval of duration. The before and the after communicate with the same absolute when not as a formal, but as a material, cause of their existence—that is, inasmuch as the same when is the subject, not the reason, of both formalities. The only relation to which the absolute when can give a foundation is one of identity with itself in all the extent of its flowing duration. But such a relation presupposes, instead of constituting, an interval in duration. And therefore it is manifest that the absolute when is not the foundation of the relation between before and after.
Having thus answered the questions proposed, and given the solution of the few difficulties objected, we must now say a few words about the division and measurement of relative duration, whether fundamental or resultant.
Fundamental or standing duration is divided into real and imaginary. This division cannot regard the entity of standing duration, which is unquestionably real, as we have proved. It regards the reality or the unreality of the extrinsic terms conceived as having a relation in duration. The true notion of real, contrasted with imaginary, duration, is the following: Standing duration is called real when it is really relative, viz., when it is extrinsically terminated by real terms between which it founds a real relation; on the contrary, it is called imaginary when the extrinsic terms do not exist in nature, but only in our imagination; for, in such a case, standing duration is not really terminated and does not found real relations, but both the terminations and the relations are simply a figment of our imagination. Thus standing duration, as containing none but imaginary relations, may justly be called “imaginary,” though in an absolute sense it is intrinsically real. Accordingly, the indefinite duration which we imagine when we carry our thought beyond the creation of the world, and which is also called “imaginary,” is not absolute but relative duration, and is not imaginary in itself, but only as to its denomination of relative, because, in the absence of all real terms, there can be none but imaginary relations.
It is therefore unphilosophical to confound imaginary and indefinite duration with absolute and infinite duration. This latter is not an object of imagination, but of the intellect alone. Imagination cannot conceive duration, except in connection with some movement from before to after; hence absolute and infinite duration, which has no before and no after, is altogether beyond the reach of imagination. Indeed, our intellectual conception of infinite standing duration is always accompanied in our minds by a representation of indefinite time; but this depends, as we have stated in speaking of space, on the well-known connection of our imaginative and intellectual operations, inasmuch as our imagination strives to follow the intellect, and to represent after its own manner what the intellect conceives in a totally different manner. It was by confounding the objective notion of duration with our subjective manner of imagining it that Kant came to the conclusion that duration was nothing but a subjective form or a subjective condition, under which all intuitions are possible in us. This conclusion is evidently false; but its refutation, to be successful, must be based on the objectivity of absolute standing duration, without which, as we have shown, there can be no field for real and objective succession.
Resultant relative duration—that is, an interval of flowing duration—admits of the same division into real and imaginary. It is real when a real continuous flowing connects the before with the after; in all other suppositions it will be imaginary. It may be remarked that the “real continuous flowing” may be either intrinsic or extrinsic. Thus, if God had created nothing but a simple angel, there would have been no other flowing duration than a continuous succession of intellectual operations connecting the before with the after in the angel himself, and thus his duration would have been measured by a series of intrinsic changes. It is evident that in this case one absolute when suffices to extend the interval of duration; for by its gliding from before to after it acquires opposite formalities through which it can be relatively opposed to itself as the subject and the term of the relation. If, on the contrary, we consider the interval of duration between two distinct beings—say Cæsar and Napoleon—then the real continuous flowing by which such an interval is measured is extrinsic to the terms compared; for the when of Cæsar is distinct from, and does not reach, that of Napoleon; which shows that their respective whens have no intrinsic connection, and that the succession comprised between those whens must have consisted of a series of changes extrinsic to the terms compared. It may seem difficult to conceive how an interval of continuous succession can result between two terms of which the one does not attain to the other; for, as a line in space must be drawn by the movement of a single point, so it seems that a length in duration must be extended by the flowing of a single when from before to after. The truth is that the interval between the whens of two distinct beings is not obtained by comparing the when of the one with that of the other, but by resorting to the when of some other being which has extended its continuous succession from the one to the other. Thus, when Cæsar died, the earth was revolving on its axis, and it continued to revolve without interruption up to the existence of Napoleon, thus extending the duration of its movement from a when corresponding to Cæsar’s death to a when corresponding to Napoleon’s birth; and this duration, wholly extrinsic to Cæsar and Napoleon, measures the interval between them.
As all intervals of duration extend from before to after, there can be no interval between co-existent beings, as is evident. In the same manner as two beings whose ubications coincide cannot be distant in space, so two beings whose whens are simultaneous cannot form an interval of duration.
All real intervals of duration regard the past; for in the past alone can we find a real before and a real after. The present gives no interval, as we have just stated, but only simultaneousness. The future is real only potentially—that is, it will be real, but it is not yet. What has never been, and never will be, is merely imaginary. To this last class belong all the intervals of duration corresponding to those conditional events which did not happen, owing to the non-fulfilment of the conditions on which their reality depended.
As to the measurement of flowing duration a few words will suffice. The when considered absolutely is incapable of measuring an interval of duration, for the reason that the when is unextended, and therefore unproportionate to the mensuration of a continuous interval; for the measure must be of the same kind with the thing to be measured. Just as a continuous line cannot be made up of unextended points, so cannot a continuous interval be made up of indivisible instants; hence, as a line is divisible only into smaller and smaller lines, by which it can be measured, so also an interval of duration is divisible only into smaller and smaller intervals, and is measured by the same. These smaller intervals, being continuous, are themselves divisible and mensurable by other intervals of less duration, and these other intervals are again divisible and mensurable; so that, from the nature of the thing, it is impossible to reach an absolute measure of duration, and we must rest satisfied with a relative one, just as in the case of a line and of any other continuous quantity. The smallest unit or measure of duration commonly used is the second, or sixtieth part of a minute.
But, since continuous quantities are divisible in infinitum, it may be asked, what prevents us from considering a finite interval of duration as containing an infinite multitude of infinitesimal units of duration? If nothing prevents us, then in the infinitesimal unit we shall have the true and absolute measure of duration. We answer that nothing prevents such a conception; but the mensuration of a finite interval by infinitesimal units would never supply us the means of determining the relative lengths of two intervals of duration. For, if every interval is a sum of infinite terms, and is so represented, how can we decide which of those intervals is the greater, since we cannot count the infinite?
Mathematicians, in all dynamical questions, express the conditions of the movement in terms of infinitesimal quantities, and consider every actual instant which connects the before with the after as an infinitesimal interval of duration in the same manner as they consider every shifting ubication as an infinitesimal interval of space. But when they pass from infinitesimal to finite quantities by integration between determinate limits, they do not express the finite intervals in infinitesimal terms, but in terms of a finite unit, viz., a second of time; and this shows that, even in high mathematics, the infinitesimal is not taken as the measure of the finite.
Since infinitesimals are considered as evanescent quantities, the question may be asked whether they are still conceivable as quantities. We have no intention of discussing here the philosophical grounds of infinitesimal calculus, as we may have hereafter a better opportunity of examining such an interesting subject; but, so far as infinitesimals of duration are concerned, we answer that they are still quantities, though they bear no comparison with finite duration. What mathematicians call an infinitesimal of time is nothing else rigorously than the flowing of an actual “when” from before to after. The “when” as such is no quantity, but its flowing is. However narrow the compass within which it may be reduced, the flowing implies a relation between before and after; hence every instant of successive duration, inasmuch as it actually links its immediate before with its immediate after, partakes of the nature of successive duration, and therefore of continuous quantity. Nor does it matter that infinitesimals are called evanescent quantities. They indeed vanish, as compared with finite quantities; but the very fact of their vanishing proves that they are still something when they are in the act of vanishing. Sir Isaac Newton, after saying in his Principia that he intends to reduce the demonstration of a series of propositions to the first and last sums and ratios of nascent and evanescent quantities, propounds and solves this very difficulty as follows: “Perhaps it may be objected that there is no ultimate proportion of evanescent quantities; because the proportion, before the quantities have vanished, is not the ultimate, and, when they are vanished, is none. But by the same argument it may be alleged that a body arriving at a certain place, and there stopping, has no ultimate velocity; because the velocity, before the body comes to the place, is not its ultimate velocity; when it has arrived, is none. But the answer is easy; for by the ultimate velocity is meant that with which the body is moved, neither before it arrives at its last place and the motion ceases, nor after, but at the very instant it arrives; that is, the velocity with which the body arrives at its last place, and with which the motion ceases. And in like manner, by the ultimate ratio of evanescent quantities is to be understood the ratio of the quantities, not before they vanish, not afterwards, but with which they vanish. In like manner, the first ratio of nascent quantities is that with which they begin to be.” From this answer, which is so clear and so deep, it is manifest that infinitesimals are real quantities. Whence we infer that every instant of duration which actually flows from before to after marks out a real infinitesimal interval of duration that might serve as a unit of measure for the mensuration of all finite intervals of succession, were it not that we cannot reckon up to infinity. Nevertheless, it does not follow that an infinitesimal duration is an absolute unit of duration; for it is still continuous, even in its infinite smallness; and accordingly it is still divisible and mensurable by other units of a lower standard. Thus it is clear that the measurement of flowing duration, and indeed of all other continuous quantity, cannot be made except by some arbitrary and conventional unit.