Let us, indeed, suppose, that something which formerly was a potentiality succeeds in assuming a form, as "potentiality that becomes a statue," or that passes to actualization, as a man's walk.421 In the case where the metal becomes a statue, this passage is a movement; in the case of the walking, the walk itself is a movement, like the dance, with one who is capable of it. In the movement of the first kind, where the metal passes into the condition of being a statue, there is the production of another form which is realized by the movement.422 The movement of the second kind, the dance, is a simple form of the potentiality, and, when it has ceased, leaves nothing that subsists after it.423
We are therefore justified in calling movement "an active form that is aroused," by opposition to the other forms which remain inactive. (They may be so named), whether or not they be permanent. We may add that it is "the cause of the other forms," when it results in producing something else. This (sense-) movement may also be called the "life of bodies." I say "this movement," because it bears the same name as the movements of the intelligence, and those of the soul.
What further proves that movement is a genus, is that it is very difficult, if not impossible, to grasp it by a definition. But how can it be called a form when its result is deterioration, or something passive? It may then be compared to the warming influence of the rays of the sun, which exerts on some things an influence that makes them grow, while other things it shrivels. In both cases, the movement has something in common, and is identical, so far as it is a movement; the difference of its results is due to the difference of the beings in which it operates. Are then growing sick and convalescence identical? Yes, so far as they are movements. Is their difference then due to their subjects, or to anything else? This question we will consider further on, while studying alteration. Now let us examine the elements common to all movements; in that way we shall be able to prove that movement is a genus.
First, the word "movement" can be used in different senses, just as essence, when considered a genus. Further, as we have already said, all the movements by which one thing arrives at a natural state, or produces an action suitable to its nature, constitute so many species. Then, the movements by which one thing arrives at a state contrary to its nature, have to be considered as analogous to that to which they lead.
But what common element is there in alteration, growth and generation, and their contraries? What is there in common between these movements, and the displacement in space, when you consider the four movements, as such?425 The common element is that the moved thing, after the movement, is no longer in the former state; that it no more remains quiet, and does not rest so long as the movement lasts. It ceaselessly passes to another state, alters, and does not remain what it was; for the movement would be vain if it did not make one thing other than it was. Consequently "otherness" does not consist in one thing becoming other than it was, and then persisting in this other state, but in ceaseless alteration. Thus, time is always different from what it was because it is produced by movement; for it is movement measured in its march and not in its limit of motion, or stopping point; it follows, carried away in its course. Further, one characteristic common to all kinds of movement is that it is the march (or process) by which potentiality and possibility pass into actualization; for every object in movement, whatever be the nature of this movement, succeeds in moving only because it formerly possessed the power of producing an action, or of experiencing the passion of some particular nature.
23. For sense-objects, which receive their impulse from without, movement is a stimulus which agitates them, excites them, presses them, prevents them from slumbering in inertia, from remaining the same, and makes them present an image of life by their agitation and continual mutations. Besides, one must not confuse the things that move with movement; walking is not the feet, but an actualization of the power connected with the feet. Now as this power is invisible, we perceive only the agitation of the feet; we see that their present state is quite different from that in which they would have been, had they remained in place, and that they have some addition, which however, is invisible. Thus, being united to objects other than itself, the power is perceived only accidentally, because one notices that the feet change place, and do not rest. Likewise, alteration in the altered object, is recognized only by failure to discover in it the same quality as before.
What is the seat of a movement acting on an object by passing from internal power to actualization? Is it in the motor? How will that which is moved and which suffers be able to receive it? Is it in the movable element? Why does it not remain in the mover? Movement must therefore be considered as inseparable from the mover, although not exclusively; it must pass from the mover into the mobile (element) without ceasing to be connected with the mover, and it must pass from the mover to the moved like a breath (or influx).426 When the motive power produces locomotion, it gives us an impulse and makes us change place ceaselessly; when it is calorific, it heats; when, meeting matter, it imparts thereto its natural organization, and produces increase; when it removes something from an object, this object decreases because it is capable thereof; last, when it is the generative power which enters into action, generation occurs; but if this generative power be weaker than the destructive power, there occurs destruction, not of what is already produced, but of what was in the process of production. Likewise, convalescence takes place as soon as the force capable of producing health acts and dominates; and sickness occurs, when the opposite power produces a contrary effect. Consequently, movement must be studied not only in the things in which it is produced, but also in those that produce it or transmit it. The property of movement consists therefore in being a movement endowed with some particular quality, or being something definite in a particular thing.
24. As to movement of displacement, we may ask if ascending be the opposite of descending, in what the circular movement differs from the rectilinear movement, what difference obtains in throwing an object at the head or at the feet. The difference is not very clear, for in these cases the motive power is the same. Shall we say that there is one power which causes raising, and another that lowers, especially if these movements be natural, and if they be the result of lightness or heaviness? In both cases, there is something in common, namely, direction towards its natural place, so that the difference is derived from exterior circumstances. Indeed, in circular and rectilinear movement, if someone move the same object in turn circularly and in a straight line, what difference is there in the motive power? The difference could be derived only from the figure (or outward appearance) of the movement, unless it should be said that the circular movement is composite, that it is not a veritable movement, and that it does not produce any change by itself. In all of these cases, the movement of displacement is identical, and presents only adventitious differences.
25. Of what do composition (blending, or mixture) and decomposition consist? Do they constitute other kinds of movement than those already noticed, generation and destruction, growth and decrease, movement of displacement and alteration? Shall composition and decomposition be reduced to some one of these kinds of motion, or shall we look at this process inversely? If composition consist in approximating one thing to another, and in joining them together; and if, on the other hand, decomposition consist in separating the things which were joined, we have here only two movements of displacement, a uniting, and a separating one. We should be able to reduce composition and decomposition to one of the above recognized kinds of motion, if we were to acknowledge that this composition was mingling,427 combination, fusion, and union—a union which consists in two things uniting, and not in being already united. Indeed, composition includes first the movement of displacement, and then an alteration; just as, in increase, there was first the movement of displacement, and then movement in the kind of the quality.428 Likewise, here there is first the movement of displacement, then the composition or decomposition, according as things approximate or separate.429 Often also decomposition is accompanied or followed by a movement of displacement, but the things which separate undergo a modification different from the movement of displacement; similarly, composition is a modification which follows the movement of displacement, but which has a different nature.
Shall we have to admit that composition and decomposition are movements which exist by themselves, and analyze alteration into them? Condensation is explained as undergoing an alteration; that means, as becoming composite. On the other hand, rarefaction is also explained as undergoing an alteration, namely, that of decomposition; when, for instance, one mingles water and wine, each of these two things becomes other than it was, and it is the composition which has operated the alteration. We will answer that here composition and decomposition no doubt precede certain alterations, but these alterations are something different than compositions and decompositions. Other alterations (certainly) are not compositions and decompositions, for neither can condensation nor rarefaction be reduced to these movements, nor are they composed of them. Otherwise, it would be necessary to acknowledge the (existence of) emptiness. Besides, how could you explain blackness and whiteness, as being composed of composition and decomposition? This doctrine would destroy all colors and qualities, or at least, the greater part of them; for if all alteration, that means, all change of quality, consisted in a composition or decomposition, the result would not be the production of a quality, but an aggregation or disaggregation. How indeed could you explain the movements of teaching and studying by mere "composition"?
26. Let us now examine the different kinds of movements. Shall we classify movements of displacement in movements upwards and downwards, rectilinear or curvilinear, or in movements of animate and inanimate beings? There is indeed a difference between the movement of inanimate beings, and that of animate beings; and these latter have different kinds of motion, such as walking, flying, and swimming. Their movements could also be analyzed in two other ways, according as it was conformable to, or against their nature; but this would not explain the outer differences of movements. Perhaps the movements themselves produce these differences, and do not exist without them; nevertheless, it is nature that seems to be the principle of the movements, and of their exterior differences. It would further be possible to classify movements as natural, artificial, and voluntary; of the natural, there are alteration and destruction; of the artificial, there are the building of houses, and construction of vessels; of the voluntary, there are meditation, learning, devoting oneself to political occupations, and, in general, speaking and acting. Last, we might, in growth, alteration and generation, distinguish the natural movement, and that contrary to nature; or even establish a classification founded on the nature of the subjects in which these movements occur.
27. Let us now study stability or stillness, which is the contrary of movement.425 Are we to consider it itself a genus, or to reduce it to some one of the known genera? First, stability rather suits the intelligible world, and stillness the sense-world. Let us now examine stillness. If it be identical with stability, it is useless to look for it here below where nothing is stable, and where apparent stability is in reality only a slower movement. If stillness be different from stability, because the latter refers to what is completely immovable, and stillness to what is actually fixed, but is naturally movable even when it does not actually move, the following distinction should be established. If stillness here below be considered, this rest is a movement which has not yet ceased, but which is imminent; if by stillness is understood the complete cessation of movement in the moved, it will be necessary to examine whether there be anything here below that is absolutely without movement. As it is impossible for one thing to possess simultaneously all the species of movement, and as there are necessarily movements that are not realized in it—since it is usual to say that some particular movement is in something—when something undergoes no displacement, and seems still in respect to this movement, should one not say about it that in this respect it is not moving? Stillness is therefore the negation of movement. Now no negation constitutes a genus. The thing we are considering is at rest only in respect to local movement; stillness expresses therefore only the negation of this movement.
It may perhaps be asked, why is movement not rather the negation of rest? We shall then answer that movement (is something positive), that it brings something with it; that it has some efficiency, that it communicates an impulsion to the subject, that produces or destroys many things; stillness, on the contrary, is nothing outside of the subject which is still, and means no more than that the latter is still.
But why should we not regard the stability of intelligible things also as a negation of movement? Because stability is not the privation of movement; it does not begin to exist when movement ceases, and it does not hinder it from simultaneous existence with it. In intelligible being, stability does not imply the cessation of movement of that whose nature it is to move.430 On the contrary, so far as intelligible being is contained in (or, expressed by) stability, it is stable; so far as it moves, it will ever move; it is therefore stable by stability, and movable by movement. The body, however, is no doubt moved by movement, but it rests only in the absence of movement, when it is deprived of the movement that it ought to have. Besides, what would stability be supposed to imply (if it were supposed to exist in sense-objects)? When somebody passes from sickness to health, he enters on convalescence. What kind of stillness shall we oppose to convalescence? Shall we oppose to it that condition from which that man had just issued? That state was sickness, and not stability. Shall we oppose to it the state in which that man has just entered? That state is health, which is not identical with stability. To say that sickness and health are each of them a sort of stability, is to consider sickness and health as species of stability, which is absurd. Further, if it were said that stability is an accident of health, it would result that before stability health would not be health. As to such arguments, let each reason according to his fancy!
28. We have demonstrated that acting and experiencing were movements; that, among the movements, some are absolute, while others constitute actions or passions.431
We have also demonstrated that the other things that are called genera must be reduced to the genera we have set forth.432
We have also studied relation, defining it as a habit, a "manner of being" of one thing in respect of another, which results from the co-operation of two things; we have explained that, when a habit of being constitutes a reference, this thing is something relative, not so much as it is being, but as far as it is a part of this being, as are the hand, the head, the cause, the principle, or the element.433 The relatives might be divided according to the scheme of the ancient (philosophers), by saying that some of them are efficient causes, while others are measures, that the former distinguish themselves by their resemblances and differences, while the latter consist in excess or in lack.
Such are our views about the (categories, or) genera (of existence).
(1.)436 When saying that eternity and time differ, that eternity refers to perpetual existence, and time to what "becomes" (this visible world), we are speaking off-hand, spontaneously, intuitionally, and common language supports these forms of expression. When however we try to define our conceptions thereof in greater detail, we become embarrassed; the different opinions of ancient philosophers, and often even the same opinions, are interpreted differently. We however shall limit ourselves to an examination of these opinions, and we believe that we can fulfil our task of answering all questions by explaining the teachings of the ancient philosophers, without starting any minute disquisition of our own. We do indeed insist that some of these ancient philosophers, these blessed men437 have achieved the truth. It remains only to decide which of them have done so, and how we ourselves can grasp their thought.
First, we have to examine that of which eternity consists, according to those who consider it as different from time; for, by gaining a conception of the model (eternity), we shall more clearly understand its image called time.438 If then, before observing eternity, we form a conception of time, we may, by reminiscence, from here below, rise to the contemplation of the model to which time, as its image, resembles.
1. (2). How shall we define the aeon (or, eternity)? Shall we say that it is the intelligible "being" (or, nature) itself, just as we might say that time is the heaven and the universe, as has been done, it seems, by certain (Pythagorean) philosophers?439 Indeed, as we conceive and judge that the aeon (eternity) is something very venerable, we assert the same of intelligible "being," and yet it is not easy to decide which of the two should occupy the first rank; as, on the other hand, the principle which is superior to them (the One) could not be thus described, it would seem that we would have the right to identify intelligible "being" (or, nature), and the aeon (or, eternity), so much the more as the intelligible world and the aeon (age, or eternity), comprise the same things. Nevertheless, were we to place one of these principles within the other, we would posit intelligible nature ("being") within the aeon (age, or eternity). Likewise, when we say that an intelligible entity is eternal, as (Plato) does:346 "the nature of the model is eternal," we are thereby implying that the aeon (age or eternity) is something distinct from intelligible nature ("being"), though referring thereto, as attribute or presence. The mere fact that both the aeon (eternity) and intelligible nature ("being"), are both venerable does not imply their identity; the venerableness of the one may be no more than derivative from that of the other. The argument that both comprise the same entities would still permit intelligible nature ("being") to contain all the entities it contains as parts, while the aeon (or age, or eternity) might contain them as wholes, without any distinctions as parts; it contains them, in this respect, that they are called eternal on its account.
Some define eternity as the "rest"440 of intelligible nature ("being"), just like time is defined as "motion" here below. In this case we should have to decide whether eternity be identical with rest in general, or only in such rest as would be characteristic of intelligible nature ("being"). If indeed eternity were to be identified with rest in general, we would first have to observe that rest could not be said to be eternal, any more than we can say that eternity is eternal, for we only call eternal that which participates in eternity; further, under this hypothesis, we should have to clear up how movement could ever be eternal; for if it were eternal, it would rest (or, it would stop). Besides, how could the idea of rest thus imply the idea of perpetuity, not indeed of that perpetuity which is in time, but of that of which we conceive when speaking of the aeonial (or, eternal)? Besides, if the rest characteristic of intelligible "being" in itself alone contain perpetuity, this alone would exclude from eternity the other genera (or categories) of existence. Further yet, eternity has to be conceived of as not only in rest, but (according to Plato438) also in unity, which is something that excludes every interval—otherwise, it would become confused with time;—now rest does not imply the idea of unity, nor that of an interval. Again, we assert that eternity resides in unity; and therefore participates in rest without being identified therewith.
2. (3). What then is that thing by virtue of which the intelligible world is eternal and perpetual? Of what does perpetuity consist? Either perpetuity and eternity are identical, or eternity is related to perpetuity. Evidently, however, eternity consists in an unity, but in an unity formed by multiple elements, in a conception of nature derived from intelligible entities, or which is united to them, or is perceived in them, so that all these intelligible entities form an unity, though this unity be at the same time manifold in nature and powers. Thus contemplating the manifold power of the intelligible world, we call "being" its substrate; movement its life; rest its permanence; difference the manifoldness of its principles; and identity, their unity.441 Synthesizing these principles, they fuse into one single life, suppressing their difference, considering the inexhaustible duration, the identity and immutability of their action, of their life and thought, for which there is neither change nor interval. The contemplation of all these entities constitutes the contemplation of eternity; and we see a life that is permanent in its identity, which ever possesses all present things, which does not contain them successively, but simultaneously; whose manner of existence is not different at various times, but whose perfection is consummate and indivisible. It therefore contains all things at the same time, as in a single point, without any of them draining off; it resides in identity, that is, within itself, undergoing no change. Ever being in the present, because it never lost anything, and will never acquire anything, it is always what it is. Eternity is not intelligible existence; it is the (light) that radiates from this existence, whose identity completely excludes the future and admits nothing but present existence, which remains what it is, and does not change.
What that it does not already possess could (intelligible existence) possess later? What could it be in the future, that it is not now? There is nothing that could be added to or subtracted from its present state; for it was not different from what it is now; and it is not to possess anything that it does not necessarily possess now, so that one could never say of it, "it was"; for what did it have that it does not now have? Nor could it be said of it, "it will be"; for what could it acquire? It must therefore remain what it is. (As Plato thought438), that possesses eternity of which one cannot say either "it was," or "will be," but only, "it is;" that whose existence is immutable, because the past did not make it lose anything, and because the future will not make it acquire anything. Therefore, on examining the existence of intelligible nature, we see that its life is simultaneously entire, complete, and without any kind of an interval. That is the eternity we seek.
3. (4). Eternity is not an extrinsic accident of (intelligible) nature, but is in it, of it, and with it. We see that it is intimately inherent in (intelligible nature) because we see that all other things, of which we say that they exist on high, are of and with this (intelligible) nature; for the things that occupy the first rank in existence must be united with the first Beings, and subsist there. Thus the beautiful is in them, and comes from them; thus also does truth dwell in them. There the whole in a certain way exists within the part; the parts also are in the whole; because this whole, really being the whole, is not composed of parts, but begets the parts themselves, a condition necessary to its being a whole. In this whole, besides, truth does not consist in the agreement of one notion with another, but is the very nature of each of the things of which it is the truth. In order, really to be a whole, this real whole must be all not only in the sense that it is all things, but also in the sense that it lacks nothing. In this case, nothing will, for it, be in the future; for to say that, for it, something "will be" for it implies that it lacked something before that, that it was not yet all; besides, nothing can happen to it against nature, because it is impassible. As nothing could happen to it, for it nothing "is to be," "will be," or "has been."
As the existence of begotten things consists in perpetually acquiring (something or another), they will be annihilated by a removal of their future. An attribution of the future to the (intelligible) entities of a nature contrary (to begotten things), would degrade them from the rank of existences. Evidently they will not be consubstantial with existence, if this existence of theirs be in the future or past. The nature ("being") of begotten things on the contrary consists in going from the origin of their existence to the last limits of the time beyond which they will no longer exist; that is in what their future consists.442 Abstraction of their future diminishes their life, and consequently their existence. That is also what will happen to the universe, in so far as it will exist; it aspires to being what it should be, without any interruption, because it derives existence from the continual production of fresh actualizations; for the same reason, it moves in a circle because it desires to possess intelligible nature ("being"). Such is the existence that we discover in begotten things, such is the cause that makes them ceaselessly aspire to existence in the future. The Beings that occupy the first rank and which are blessed, have no desire of the future, because they are already all that it lies in them to be, and because they possess all the life they are ever to possess. They have therefore nothing to seek, since there is no future for them; neither can they receive within themselves anything for which there might be a future. Thus the nature ("being") of intelligible existence is absolute, and entire, not only in its parts, but also in its totality, which reveals no fault, which lacks nothing, and to which nothing that in any way pertains to nonentity could be added; for intelligible existence must not only embrace in its totality and universality all beings, but it must also receive nothing that pertains to nonentity. It is this disposition and nature of intelligible existence that constitutes the aeon (or eternity); for (according to Aristotle)443 this word is derived from "aei on," "being continually."
4. (5). That this is the state of affairs appears when, on applying one's intelligence to the contemplation of some of the intelligible Entities, it becomes possible to assert, or rather, to see that it is absolutely incapable of ever having undergone any change; otherwise, it would not always exist; or rather, it would not always exist entirely. Is it thus perpetual? Doubtless; its nature is such that one may recognize that it is always such as it is, and that it could never be different in the future; so that, should one later on again contemplate it, it will be found similar to itself (unchanged). Therefore, if we should never cease from contemplation, if we should ever remain united thereto while admiring its nature, and if in that actualization we should show ourselves indefatigable, we would succeed in raising ourselves to eternity; but, to be as eternal as existence, we must not allow ourselves to be in anyway distracted from contemplating eternity, and eternal nature in the eternal itself. If that which exists thus be eternal, and exists ever, evidently that which never lowers itself to an inferior nature; which possesses life in its fulness, without ever having received, receiving, or being about to receive anything; this nature would be "aidion," or perpetual. Perpetuity is the property constitutive of such a substrate; being of it, and in it.443 Eternity is the substrate in which this property manifests. Consequently reason dictates that eternity is something venerable, identical with the divinity.444 We might even assert that the age ("aion," or eternity) is a divinity that manifests within itself, and outside of itself in its immutable and identical existence, in the permanence of its life. Besides, there is nothing to surprise any one if in spite of that we assert a manifoldness in the divinity. Every intelligible entity is manifoldness because infinite in power, infinite in the sense that it lacks nothing; it exercises this privilege peculiarly because it is not subject to losing anything.
Eternity, therefore, may be defined as the life that is at present infinite because it is universal and loses nothing, as it has no past nor future; otherwise it would no longer be whole. To say that it is universal and loses nothing explains the expression: "the life that is at present infinite."
5. (6). As this nature that is eternal and radiant with beauty refers to the One, issues from Him, and returns to Him, as it never swerves from Him, ever dwelling around Him and in Him, and lives according to Him, Plato was quite right438 in saying not casually, but with great profundity of thought, that "eternity is immutable in unity." Thereby Plato not only reduces the eternity to the unity that it is in itself, but also relates the life of existence to the One itself. This life is what we seek; its permanence is eternity. Indeed that which remains in that manner, and which remains the same thing, that is, the actualization of that life which remains turned towards, and united with the One, that whose existence and life are not deceptive, that truly is eternity. (For intelligible or) true existence is to have no time when it does not exist, no time when it exists in a different manner; it is therefore to exist in an immutable manner without any diversity, without being first in one, and then in another state. To conceive of (existence), therefore, we must neither imagine intervals in its existence, nor suppose that it develops or acquires, nor believe that it contains any succession; consequently we could neither distinguish within it, or assert within it either before or after. If it contain neither "before" nor "after," if the truest thing that can be affirmed of it be that it is, if it exist as "being" and life, here again is eternity revealed. When we say that existence exists always, and that there is not one time in which it is, and another in which it is not, we speak thus only for the sake of greater clearness; for when we use the word "always," we do not take it in an absolute sense; but if we use it to show that existence is incorruptible, it might well mislead the mind in leading it to issue out from the unity (characteristic of eternity) to make it run through the manifold (which is foreign to eternity). "Always" further indicates that existence is never defective. It might perhaps be better to say simply "existence." But though the word "existence" suffices to designate "being," as several philosophers have confused "being" with generation, it was necessary to clear up the meaning of existence by adding the term "always." Indeed, though we are referring only to one and the same thing by "existence" and "existing always," just as when we say "philosopher," and "the true philosopher," nevertheless, as there are false philosophers, it has been necessary to add to the term "philosophers" the adjective "true." Likewise, it has been necessary to add the term "always" to that of "existing," and that of "existing" to that of "always;" that is the derivation of the expression "existing always," and consequently (by contraction), "aion," or, eternity. Therefore the idea "always" must be united to that of "existing," so as to designate the "real being."
"Always" must therefore be applied to the power which contains no interval in its existence, which has need of nothing outside of what it possesses, because it possesses everything, because it is every being, and thus lacks nothing. Such a nature could not be complete in one respect, but incomplete in another. Even if what is in time should appear complete, as a body that suffices the soul appears complete, though it be complete only for the soul; that which is in time needs the future, and consequently is incomplete in respect to the time it stands in need of; when it succeeds in enjoying the time to which it aspires, and succeeds in becoming united thereto, even though it still remain imperfect it still is called perfect by verbal similarity. But the existence whose characteristic it is not to need the future, not to be related to any other time—whether capable of being measured, or indefinite, and still to be indefinite—the existence that already possesses all it should possess is the very existence that our intelligence seeks out; it does not derive its existence from any particular quality, but exists before any quantity. As it is not any kind of quantity, it could not admit within itself any kind of quantity. Otherwise, as its life would be divided, it would itself cease to be absolutely indivisible; but existence must be as indivisible in its life as in its nature ("being"). (Plato's expression,446) "the Creator was good" does indeed refer to the notion of the universe, and indicates that, in the Principle superior to the universe, nothing began to exist at any particular time. Never, therefore, did the universe begin to exist within time, because though its Author existed "before" it, it was only in the sense that its author was the cause of its existence. But, after having used the word "was," to express this thought, Plato immediately corrects himself, and he demonstrates that this word does not apply to the Things that possess eternity.
6. (7). Speaking thus of eternity, it is not anything foreign to us, and we do not need to consult the testimony of anybody but ourselves. For indeed, how could we understand anything that we could not perceive? How could we perceive something that would be foreign to us? We ourselves, therefore, must participate in eternity. But how can we do so, since we are in time? To understand how one can simultaneously be in time and in eternity, it will be necessary to study time. We must therefore descend from eternity to study time. To find eternity, we have been obliged to rise to the intelligible world; now we are obliged to descend therefrom to treat of time; not indeed descending therefrom entirely, but only so far as time itself descended therefrom.
If those blessed ancient philosophers had not already uttered their views about time, we would only need to add to the idea of eternity what we have to say of the idea of time, and to set forth our opinion on the subject, trying to make it correspond with the already expressed notion of eternity. But we now must examine the most reasonable opinions that have been advanced about time, and observe how far our own opinion may conform thereto.
To begin with, we may divide the generally accepted opinions about time into three classes: time as movement, as something movable, or as some part of movement. It would be too contrary to the notion of time to try to define it as rest, as being at rest, or as some part of rest; for time is incompatible with identity (and consequently with rest, and with what is at rest). Those who consider time as movement, claim that it is either any kind of movement, or the movement of the universe. Those who consider it as something movable are thinking of the sphere of the universe; while those who consider time as some part of movement consider it either as the interval of movement, or as its measure, or as some consequence of movement in general, or regular 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
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).
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.
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.
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).
8. (9). Let us now examine in what sense it may be said (by Aristotle452) that time is the number and measure of movement, which definition seems more reasonable, because of the continuity of movement. To begin with, following the method adopted with the definition of time as "the interval of movement," we might ask whether time be the measure and number of any kind of movement.453 For how indeed could we give a numerical valuation of unequal or irregular movement. What system of numbering or measurement shall we use for this? If the same measure be applied to slow or to swift movement, in their case measure and number will be the same as the number ten applied equally to horses and oxen; and further, such measure might also be applied to dry and wet substances. If time be a measure of this kind, we clearly see that it is the measure of movements, but we do not discover what it may be in itself. If the number ten can be conceived as a number, after making abstraction of the horses it served to measure, if therefore a measure possess its own individuality, even while no longer measuring anything, the case must be similar with time, inasmuch as it is a measure. If then time be a number in itself, in what does it differ from the number ten, or from any other number composed of unities? As it is a continuous measure, and as it is a quantity, it might, for instance, turn out to be something like a foot-rule. It would then be a magnitude, as, for instance, a line, which follows the movement; but how will this line be able to measure what it follows? Why would it measure one thing rather than another? It seems more reasonable to consider this measure, not as the measure of every kind of movement, but only as the measure of the movement it follows.452 Then that measure is continuous, so far as the movement it follows itself continue to exist. In this case, we should not consider measure as something exterior, and separated from movement, but as united to the measured movement. What then will measure? Is it the movement that will be measured, and the extension that will measure it? Which of these two things will time be? Will it be the measuring movement, or the measuring extension? Time will be either the movement measured by extension, or the measuring extension; or some third thing which makes use of extension, as one makes use of a foot-rule, to measure the quantity of movement. But in all these cases, we must, as has already been noticed, suppose that movement is uniform; for unless the movement be uniform, one and universal, the theory that movement is a measure of any kind whatever will become almost impossible. If time be "measured movement," that is, measured by quantity—besides granting that it at all needs to be measured—movement must not be measured by itself, but by something different. On the other hand, if movement have a measure different from itself, and if, consequently, we need a continuous measure to measure it, the result would be that extension itself would need measure, so that movement, being measured, may have a quantity which is determined by that of the thing according to which it is measured. Consequently, under this hypothesis, time would be the number of the extension which follows movement, and not extension itself which follows movement.
What is this number? Is it composed of unities? How does it measure? That would still have to be explained. Now let us suppose that we had discovered how it measures; we would still not have discovered the time that measures, but a time that was such or such an amount. Now that is not the same thing as time; there is a difference between time and some particular quantity of time. Before asserting that time has such or such a quantity, we have to discover the nature of that which has that quantity. We may grant that time is the number which measures movement, while remaining exterior thereto, as "ten" is in "ten horses" without being conceived with them (as Aristotle claimed, that it was not a numbering, but a numbered number). But in this case, we still have to discover the nature of this number that, before numbering, is what it is, as would be "ten" considered in itself.454 It may be said that it is that number which, by following number, measures according to the priority and posteriority of that movement.452 Nor do we yet perceive the nature of that number which measures by priority and posteriority. In any case, whatever measures by priority or posteriority, or by a present moment,455 or by anything else, certainly does measure according to time. Thus this number (?) which measures movement according to priority or posteriority, must touch time, and, to measure movement, be related thereto. Prior and posterior necessarily designate either different parts of space, as for instance the beginning of a stadium, or parts of time. What is called priority is time that ends with the present; what is called posteriority, is the time that begins at the present. Time therefore is something different from the number that measures movement according to priority or posteriority,—I do not say, any kind of movement, but still regular movement. Besides, why should we have time by applying number either to what measures, or to what is measured? For in this case these two may be identical. If movement exist along with the priority and posteriority which relate thereto, why will we not have time without number? This would amount to saying that extension has such a quantity only in case of the existence of somebody who recognizes that it possesses that quantity. Since (Aristotle456) says that time is infinite, and that it is such effectually, how can it contain number without our taking a portion of time to measure it? From that would result that time existed before it was measured. But why could time not exist before the existence of a soul to measure it? (Aristotle) might have answered that it was begotten by the soul. The mere fact that the soul measures time need not necessarily imply that the soul produced the time; time, along with its suitable quantity, would exist even if nobody measured it. If however it be said that it is the soul that makes use of extension to measure time, we will answer that this is of no importance to determine the notion of time.
9. (10). When (Epicurus457) says that time is a consequence of movement, he is not explaining the nature of time; this would demand a preliminary definition of the consequence of movement. Besides, this alleged consequence of movement—granting the possibility of such a consequence—must be prior, simultaneous, or posterior. For, in whatever way we conceive of it, it is within time. Consequently, if the consequence of movement be time, the result would be that time is a consequence of movement in time (which is nonsense).
Now, as our purpose is to discover, not what time is not, but what it really is, we notice that this question has been treated at great length by many thinkers before us; and if we were to undertake to consider all existing opinions on the subject, we would be obliged to write a veritable history of the subject. We have here, however, gone to the limit of our ability in treating it without specializing in it. As has been seen, it is easy enough to refute the opinion that time is the measure of the movement of the universe, and to raise against this opinion the objections that we have raised against the definition of time as the measure of movement in general, opposing thereto the irregularity of movement, and the other points from which suitable arguments may be drawn. We are therefore free to devote ourselves to an explanation of what time really is.
10. (11). To accomplish this we shall have to return to the nature which, as we pointed out above, was essential to eternity; that immutable life, wholly realized all at once, infinite and perfect, subsisting in, and referring to unity. Time was not yet, or at least, it did not yet exist for the intelligible entities. Only, it was yet to be born of them,458 because (as was the world), time, by both its reason and nature, was posterior to the (intelligible entities459). Are we trying to understand how time issued from among intelligible entities while these were resting within themselves? Here it would be useless to call upon the Muses, for they did not yet exist. Still this might perhaps not be useless; for (in a certain sense, that time had already begun, then, so far as they existed within the sense-world) they existed already. In any case, the birth of time will be plain enough if we consider it only as it is born and manifested. Thus much can be said about it.
Before priority and posteriority, time, which did not yet exist, brooded within existence itself. But an active nature (the universal Soul), which desired to be mistress of herself, to possess herself, and ceaselessly to add to the present, entered into motion, as did time, along with (the Soul). We achieve a representation of the time that is the image of eternity, by the length that we must go through with to reach what follows, and is posterior, towards one moment, and then towards another.460
As the universal Soul contained an activity that agitated her, and impelled her to transport into another world what she still saw on high, she was willing to retain all things that were present at the same time. (Time arose not by a single fiat, but as the result of a process. This occurred within the universal Soul, but may well be first illustrated by the more familiar process within) Reason, which distributes unity, not indeed That which remains within itself, but that which is exterior to itself. Though this process seem to be a strengthening one, reason developing out of the seed in which it brooded unto manifoldness, it is really a weakening (or destructive one), inasmuch as it weakened manifoldness by division, and weakened reason by causing it to extend. The case was similar with the universal Soul. When she produced the sense-world, the latter was animated by a movement which was only an image of intelligible movement. (While trying to strengthen) this image-movement to the extent of the intelligible movement, she herself (weakened), instead of remaining exclusively eternal, became temporal and (involuntarily) subjected what she had produced to the conditions of time, transferring entirely into time not only the universe, but also all its revolutions. Indeed, as the world moves within the universal Soul, which is its location, it also moves within the time that this Soul bears within herself.461 Manifesting her power in a varied and successive manner, by her mode of action, the universal Soul begat succession. Indeed, she passes from one conception to another, and consequently to what did not exist before, since this conception was not effective, and since the present life of the soul does not resemble her former life. Her life is varied, and from the variety of her life results the variety of time.462