Plotino - Tratado 45,7 (III, 7, 7) — O que é o tempo? (Introdução)

7. Ahora bien, cuando hablamos de todo esto, ¿contamos nosotros con otro testimonio que el de nosotros mismos y exponemos razones sobre cosas realmente extrañas? ¿Cómo podríamos hacerlo? ¿Y cómo tomar conciencia de esas cosas, si no mantenemos contacto con ellas? Porque, ¿cómo mantendríamos contacto con cosas que nos son extrañas? Conviene, pues, que nosotros mismos participemos en la eternidad. Pero, ¿cómo, si estamos inmersos en el tiempo? Hemos de descender de la eternidad para emprender la búsqueda del tiempo. Porque hasta este momento nuestra marcha rondaba la región inteligible, y ahora precisamente hemos de descender, no hasta lo más profundo, sino al nivel mismo del tiempo.

Si los hombres antiguos y bienaventurados nada hubiesen dicho del tiempo, tendríamos que empezar por hablar de la eternidad, tratando luego de acomodar nuestra opinión a la idea que tenemos del tiempo; mas, como los antiguos ya han tratado la cuestión, hemos de ajustar nuestra opinión a la de ellos, exponiendo primero las teorías más importantes que han formulado sobre esto y buscando la concordancia de nuestras razones con alguna de las de aquéllos. Tal vez convenga dividir en tres clases las teorías sobre el tiempo. Según lo que dicen los filósofos, el tiempo o es un movimiento, o algo movido, o algo propio del movimiento. Lejos de todo cálculo sería el afirmar que el movimiento es el reposo, o algo en reposo, o algo propio del reposo, pues resulta evidente que el movimiento nunca es lo mismo. Quienes consideran el tiempo como un movimiento hablan, en un caso, de un movimiento determinado, y en otro, de un movimiento del universo. Quienes lo tienen por algo movido dicen que es la esfera del universo. Y quienes, en fin, lo estiman como algo propio del movimiento, afirman unas veces que se trata de un intervalo del movimiento, y otras que es su propia medida, e inclusive, en ocasiones, lo califican de su acompañante inseparable. También se dice del liempo que va unido a todo movimiento o sólo al movimiento ordenado.

VII. Il est impossible que le temps soit le mouvement (33), soit qu’on prenne tous les mouvements ensemble de manière à n’en faire qu’un seul, soit que l’on considère seulement le mouvement régulier : car ces deux espèces de mouvement sont dans le temps (34). Si l’on suppose qu’il y a un mouvement qui ne s’opère pas dans le temps, ce mouvement sera encore bien plus éloigné d’être le temps, puisque, dans cette hypothèse, autre chose est ce dans quoi se produit le mouvement, autre chose le mouvement même. Parmi les raisons qui ont été alléguées et qui sont alléguées pour réfuter cette opinion, une seule suffit : c’est que le mouvement peut cesser et s’arrêter, tandis que le temps ne saurait suspendre son cours (35). Si l’on dit que le mouvement de l’univers ne s’interrompt jamais, nous répondrons que ce mouvement, s’il consiste dans le mouvement circulaire [des astres] (36), s’opère dans un temps déterminé, au bout duquel il revient au même point du ciel, mais il ne le fait pas dans le même espace de temps qu’il emploie pour fournir la moitié de son cours : l’un de ces deux mouvements n’est que moitié de l’autre et le second est le double ; tous les deux d’ailleurs, celui qui ne parcourt que la moitié de l’espace, et celui qui en parcourt la totalité, sont des mouvements de l’univers. En outre, on a remarqué que le mouvement de la sphère extérieure a le plus de vitesse. Cette distinction vient encore à l’appui de nos idées : car elle implique que le mouvement de cette sphère, et le temps qu’elle emploie pour l’opérer, sont choses différentes : le mouvement le plus rapide est celui qui emploie le moins de temps et parcourt le plus grand espace ; les mouvements plus lents sont ceux qui emploient plus de temps et ne parcourent qu’une partie de cet espace (37).

D’un autre côté, si le temps n’est pas le mouvement de la sphère, évidemment il est bien moins encore [le mobile ], la sphère même, comme quelques-uns l’ont cru parce qu’elle se meut (38). [Par cela seul se trouve écartée l’opinion qui confond le temps avec le mobile.]

Le temps enfin est-il quelque chose du mouvement ?

Si l’on dit qu’il est l’intervalle du mouvement (39), nous ferons remarquer que l’intervalle n’est pas le même pour tous les mouvements, fussent-ils de même nature : car les mouvements qui s’opèrent dans le lieu peuvent être plus rapides ou plus lents. Il est possible que les intervalles du mouvement plus rapide et du mouvement plus lent soient mesurés par un troisième intervalle, qui mériterait avec plus de raison d’être appelé le temps. Lequel de ces trois intervalles sera le temps, ou plutôt lequel de tous les intervalles, puisqu’il y en a un nombre infini? Si l’on regarde le temps comme l’intervalle du mouvement régulier, il ne sera pas l’intervalle même de tout mouvement régulier; sinon, comme il y a plusieurs mouvements réguliers, il y aurait plusieurs temps. Si l’on définit le temps l’intervalle du mouvement de l’univers, c’est-à-dire l’intervalle qui est dans ce mouvement, que sera-ce autre chose que le mouvement même ?

Ce mouvement d’ailleurs est une quantité déterminée. Ou bien cette quantité sera mesurée par l’étendue du lieu parcouru, et l’intervalle consistera dans cette étendue ; mais cette étendue est le lieu et non le temps. Ou bien l’on dira que le mouvement a un certain intervalle parce qu’il est continu, qu’au lieu de s’arrêter sur-le-champ il se prolonge toujours: mais cette continuité n’est autre chose que la grandeur [la durée] du mouvement (40). Si, après avoir considéré un mouvement, on affirme qu’il est grand, comme on dirait d’une chaleur qu’elle est grande, on n’a encore là aucune chose dans laquelle le temps puisse apparaître et se manifester ; on n’a qu’une suite de mouvements qui se succèdent comme des flots, et que l’intervalle qu’on observe entre eux; or, la suite des mouvements forme un nombre, deux, trois, par exemple ; et l’intervalle est une étendue. Ainsi, la grandeur du mouvement sera un nombre comme dix, par exemple, ou bien un intervalle qui se manifeste dans l’étendue parcourue par le mouvement. Or, on ne découvre point là la notion du temps, mais seulement une quantité qui se produit dans le temps : sinon le temps, au lieu d’être partout, n’existera que dans le mouvement comme un attribut dans un sujet, ce qui revient à dire que le temps est le mouvement : car l’intervalle [du mouvement] n’est pas en dehors du mouvement, ce n’est qu’un mouvement non instantané. Si le temps est un mouvement non instantané, comme l’on dit que tel ou tel fait instantané s’opère dans le temps, nous demanderons quelle différence il y a entre ce qui est instantané et ce qui ne l’est pas. Ces choses diffèrent-elles sous le rapport du temps? Alors le mouvement qui dure et son intervalle ne sont pas le temps, mais sont dans le temps.

Dira-t-on que le temps est bien l’intervalle du mouvement, mais qu’il n’est pas l’intervalle propre du mouvement même, qu’il est seulement l’intervalle dans lequel le mouvement a son extension (παρατάσιν ἔχει), en le suivant en quelque sorte (συμπαραθέουσα) ? On ne définit pas encore quelle est cette chose. Évidemment elle n’est autre que le temps dans lequel se produit le mouvement. Mais c’est là précisément ce que nous nous sommes dès le commencement proposé de déterminer. C’est comme si, prié de définir le temps, on répondait : le temps est l’intervalle du mouvement produit dans le temps. Quel est donc cet intervalle qu’on appelle le temps, quand on le considère en dehors de l’intervalle propre au mouvement ? Si l’on fait consister dans le mouvement l’intervalle propre au temps, où placera-t-on la durée du repos? En effet, pour qu’un objet soit en mouvement, il faut qu’un autre soit en repos; or le temps de ces objets est le même, quoiqu’il soit pour l’un le temps du mouvement, et pour l’autre, celui du repos (41). Quelle est donc la nature de cet intervalle? Ce ne peut être un intervalle de lieu, puisque le lieu est extérieur [aux mouvements qui s’accomplissent dans son sein].

POLEMIC AGAINST THE STOICS; TIME IS NOT MOVEMENT.

7. (8). Time cannot (as the Stoics claim,447) be movement. Neither can we gather together all movements, so as to form but a single one, nor can we consider the regular movement only; for these two kinds of motion are within time. If we were to suppose that there was a movement that did not operate within time, such a movement would still be far removed from being time, since, under this hypothesis, the movement itself is entirely different from that in which the movement occurs. Amidst the many reasons which, in past and present, have been advanced to refute this opinion, a single one suffices: namely, that movement can cease and stop, while time never suspends its flight. To the objection that the movement of the universe never stops, we may answer that this movement, if it consist in the circular movement (of the stars, according to Hestius of Perinthus; or of the sun, according to Eratosthenes447) operates within a definite time, at the end of which it returns to the same point of the heavens, but it does not accomplish this within the same space of time taken up in fulfilling the half of its course. One of these movements is only half of the other, and the second is double. Besides, both, the one that runs through half of space, and the one that runs through the whole of it, are movements of the universe. Besides, it has been noticed that the movement of the exterior sphere is the swiftest. This distinction supports our view, for it implies that the movement of this sphere, and the time used to operate it, are different entities; the most rapid movement is the one that takes up the least time, and runs through the greatest amount of space; the slowest movements are those that employ the longest time, and run through only a part of that space.448

POLEMIC AGAINST THE PYTHAGOREANS: TIME IS NOT WHAT IS MOVABLE.

On the other hand, if time be not the movement of the sphere, evidently it is far less (than that which is movable, as thought the Pythagoreans,449) or (as Pythagoras   thought), the sphere (of heaven) itself, as some have thought, because it moves. (This fact alone is sufficient to refute the opinion that confuses time with that which is movable).

POLEMIC AGAINST THE STOIC ZENO  : TIME IS NO INTERVAL OF MOVEMENT.

Is time then some part of movement? (Zeno450) calls it the interval of movement; but the interval is not the same for all movements, even if the latter were of similar nature; for movements that operate within space may be swifter or slower. It is possible that the intervals of the most rapid and of the slowest movement might be measured by some third interval, which might far more reasonably be considered time. But which of these three intervals shall be called time? Rather, which of all the intervals, infinite in number as they are, shall time be? If time be considered the interval of the regular movement, it will not be the particular interval of every regular movement; otherwise, as there are several regular movements, there would be several kinds of time. If time be defined as the interval of movement of the universe, that is, the interval contained within this movement, it will be nothing else than this movement itself.

PERSISTENT MOVEMENT AND ITS INTERVAL ARE NOT TIME, BUT ARE WITHIN IT.

Besides, this movement is a definite quantity. Either this quantity will be measured by the extension of the space traversed, and the interval will consist in that extension; but that extension is space, and not time. Or we shall say that movement has a certain interval because it is continuous, and that instead of stopping immediately it always becomes prolonged; but this continuity is nothing else than the magnitude (that is, the duration) of the movement. Even though after consideration of a movement it be estimated as great, as might be said of a "great heat"-this does not yet furnish anything in which time might appear and manifest; we have here only a sequence of movements which succeed one another like waves, and only the observed interval between them; now the sequence of movements forms a number, such as two or three; and the interval is an extension. Thus the magnitude of the movement will be a number, say, such as ten; or an interval that manifests in the extension traversed by the movement. Now the notion of time is not revealed herein, but we find only a quantity that is produced within time. Otherwise, time, instead of being everywhere, will exist only in the movement as an attribute in a substrate, which amounts to saying that time is movement; for the interval (of the movement) is not outside of movement, and is only a non-instantaneous movement. If then time be a non-instantaneous movement, just as we often say that some particular instantaneous fact occurs within time, we shall be forced to ask the difference between what is and what is not instantaneous. Do these things differ in relation to time? Then the persisting movement and its interval are not time, but within time.

POLEMIC AGAINST STRATO: TIME IS NOT MOTION AND REST.

Somebody might object that time is indeed the interval of movement, but that it is not the characteristic interval of movement itself, being only the interval in which movement exerts its extension, following along with it. All these terms lack definition. This (extension) is nothing else than the time within which the movement occurs. But that is precisely the question at issue, from the very start. It is as if a person who had been asked to define time should answer "time is the interval of the movement produced within time." What then is this interval called time, when considered outside of the interval characteristic of movement? If the interval characteristic of time be made to consist in movement, where shall the duration of rest be posited? Indeed, for one object to be in motion implies that another (corresponding object) is at rest; now the time of these objects is the same, though for one it be the time of movement, and for the other the time of rest (as thought Strato451). What then is the nature of this interval? It cannot be an interval of space, since space is exterior (to the movements that occur within it).

VII. It is not, indeed, possible, that time should be motion, neither if all motions are assumed, and one as it were is produced from all of them, nor if that motion is assumed which is orderly. For each of these motions is in time. If, however, some one should say that motion is not in time, much less will motion be time ; since that in which motion is, is one thing, and motion itself another a thing. Since, however, there are beside these other assertions, it may be sufficient to observe, that motion may indeed cease and be interrupted, but time cannot. But if some one should say that the motion of the universe is not interrupted, yet this motion, if it is admitted that the circulation [of the world] is in a certain time, will itself be carried round to the same point from whence it began ; and not to that point in which the half of it only is accomplished. And this motion, indeed, will be the half, but the other will be double, each being the motion of the universe, both that which proceeds from the same to the same, and that which arrives only at the half. The assertion, also, that the motion of the outermost sphere is most vehement and rapid, bears witness to what we say ; so that the motion of it is one thing, and time another. For that motion is the most rapid of all, which in the least time passes through the greatest interval. But other motions are slower, which are performed in a longer time, and pass through a part only of the same space. If, therefore, time is not the motion of the outermost sphere, much less will it be that sphere itself, which in consequence of being moved is conceived to be time. Is, therefore, time something belonging to motion? If indeed it is interval, in the first place, there is not the same interval of every motion, nor of uniform motion. For the motion which is in place is swifter and slower, and both the intervals may be measured by another third interval, which may with greater rectitude be dominated time. But of which of these motions will time be the interval ? Or rather, will it be the interval of any one of them, since they are infinite? And if time is the interval of orderly motion, it is not the interval of every motion, nor of every motion of this kind. For these are many. So that there will also be at once many times. But if time is the interval of the universe, if indeed it is the interval in motion itself, #what else will it be than motion, viz. so much; and this quantity of motion will either be measured by place, because the place which it passes through is so much in quantity, and the interval will be this. This, however, is not time, but place. Or motion by its continuity, and from not immediately ceasing, but being always assumed, possesses interval. But this will be the multitude of motion. And if some one looking to motion should assert that it is much, just as if it should be said that beat is much, neither will time here also present itself to our view, nor become obvious; but motion again and again will occur, like water repeatedly flowing, and also the interval which is beheld in it. The again and again also will be number, as the duad or the triad; but the interval will belong to bulk. Thus, therefore, the multitude of motion will be as the decad, or as the interval which is beheld as it were in the bulk of motion, which is not attended with a conception of time. But this quantity of motion will be generated in time ; for otherwise, time will not be every where, but will be in motion as in a subject. It will, likewise, again happen that time will be said to be motion. For the interval is not external to motion, but is motion not at once collected together. But if it is not at once collected, if an at-once-collected subsistence is in time, in what respect does that which is not at-once-collected differ from that which is ? Shall we say that they differ in time; so that the separating motion, and the interval of it, are not time itself, but subsist in time ? If, however, some one should say, that the interval of motion is time, by the interval not meaning the peculiarity of motion, but that with which motion has an extension, as if running together with it, yet what this is, is not unfolded. For it is evident that time is that in which the motion was generated. This, therefore, is that which was investigated from the first, viz. what that existing thing is which is time; since thjs is just as if some one being asked what time is, should say that the interval of motion is in time. What, therefore, is this interval, which he calls time, who supposes it to be external to the proper interval of motion ? For again, he who places temporal interval in motion itself, will be dubious where he should place the interval of rest. For as much as a certain thing is moved, so much also will something else have been quiescent. And you may say that the time of each is the same, though its relation to the one, is different from its relation to the other. What therefore is this interval, and what nature does it possess ? For it is not possible that it should be local since this has an external subsistence.

7. Now comes the question whether, in all this discussion, we are not merely helping to make out a case for some other order of Beings and talking of matters alien to ourselves.

But how could that be? What understanding can there be failing some point of contact? And what contact could there be with the utterly alien?

We must then have, ourselves, some part or share in Eternity.

Still, how is this possible to us who exist in Time?

The whole question turns on the distinction between being in Time and being in Eternity, and this will be best realized by probing to the Nature of Time. We must, therefore, descend from Eternity to the investigation of Time, to the realm of Time: till now we have been taking the upward way; we must now take the downward - not to the lowest levels but within the degree in which Time itself is a descent from Eternity.

If the venerable sages of former days had not treated of Time, our method would be to begin by linking to [the idea of] Eternity [the idea of] its Next [its inevitable downward or outgoing subsequent in the same order], then setting forth the probable nature of such a Next and proceeding to show how the conception thus formed tallies with our own doctrine.

But, as things are, our best beginning is to range over the most noteworthy of the ancient opinions and see whether any of them accord with ours.

Existing explanations of Time seem to fall into three classes:

Time is variously identified with what we know as Movement, with a moved object, and with some phenomenon of Movement: obviously it cannot be Rest or a resting object or any phenomenon of rest, since, in its characteristic idea, it is concerned with change.

Of those that explain it as Movement, some identify it with Absolute Movement [or with the total of Movement], others with that of the All. Those that make it a moved object would identify it with the orb of the All. Those that conceive it as some phenomenon, or some period, of Movement treat it, severally, either as a standard of measure or as something inevitably accompanying Movement, abstract or definite.