(40) Timaeus: and the other is a forward motion due to its being dominated by the revolution of the Same and Similar; but in respect of the other five motions they are at rest and move not, so that each of them may attain the greatest possible perfection. From this cause, then, came into existence all those unwandering stars which are living creatures divine and eternal and abide for ever revolving uniformly in the same spot; and those which keep swerving and wandering have been generated in the fashion previously described. And Earth, our nurse, which is globed around the pole that stretches through all,

(2) And so, although Eternity is stable, motionless, and fixed, still, seeing that the movement of [this] Time (which is subject to motion) is ever being recalled into Eternity,—and for that reason Time’s mobility is circular,—it comes to pass that the Eternity itself, although in its own self, is motionless, [yet] on account of Time, in which it is—(and it is in it),—it seems to be in movement as all motion. So that it comes to pass, that both Eternity’s stability becometh moved, and Time’s mobility becometh stable. So may we ever hold that God Himself is moved into Himself by [ever-] same transcendency of motion. For that stability is in His vastness motion motionless; for by His vastness is [His] law exempt from change.

(23) The Motion which acts upon Sensible objects enters from without, and so shakes, drives, rouses and thrusts its participants that they may neither rest nor preserve their identity- and all to the end that they may be caught into that restlessness, that flustering excitability which is but an image of Life.

We must avoid identifying Motion with the objects moved: by walking we do not mean the feet but the activity springing from a potentiality in the feet. Since the potentiality is invisible, we see of necessity only the active feet- that is to say, not feet simply, as would be the case if they were at rest, but something besides feet, something invisible but indirectly seen as an accompaniment by the fact that we observe the feet to be in ever-changing positions and no longer at rest. We infer alteration, on the other hand, from the qualitative change in the thing altered.

Where, then, does Motion reside, when there is one thing that moves and another that passes from an inherent potentiality to actuality? In the mover? How then will the moved, the patient, participate in the motion? In the moved? Then why does not Motion remain in it, once having come? It would seem that Motion must neither be separated from the active principle nor allowed to reside in it; it must proceed from agent to patient without so inhering in the latter as to be severed from the former, passing from one to the other like a breath of wind.

Now, when the potentiality of Motion consists in an ability to walk, it may be imagined as thrusting a man forward and causing him to be continually adopting a different position; when it lies in the capacity to heat, it heats; when the potentiality takes hold of Matter and builds up the organism, we have growth; and when another potentiality demolishes the structure, the result is decay, that which has the potentiality of demolition experiencing the decay. Where the birth-giving principle is active, we find birth; where it is impotent and the power to destroy prevails, destruction takes place- not the destruction of what already exists, but that which intervenes upon the road to existence.

Health comes about in the same way- when the power which produces health is active and predominant; sickness is the result of the opposite power working in the opposite direction.

Thus, Motion is conditioned, not only by the objects in which it occurs, but also by its origins and its course, and it is a distinctive mark of Motion to be always qualified and to take its quality from the moved.

(89) Timaeus: Further, as concerns the motions, the best motion of a body is that caused by itself in itself; for this is most nearly akin to the motion of intelligence and the motion of the Universe. Motion due to the agency of another is less good; and the least good motion is that which is imparted to a body lying in a state of rest and which moves it piecemeal and by means of others. Wherefore the motion that is best for purgings and renovations of the body consists in gymnastic exercises; and second-best is the motion provided by swaying vehicles, such as boats or any conveyances that produce no fatigue; while the third kind of motion, although useful for one who is absolutely driven to it,

(2) All things descend from Heaven to Earth, to Water and to Air. ’Tis Fire alone, in that it is borne upwards, giveth life; that which [is carried] downwards [is] subservient to Fire. Further, whatever doth descend from the above, begetteth; what floweth upwards, nourisheth. ’Tis Earth alone, in that it resteth on itself, that is Receiver of all things, and [also] the Restorer of all genera that it receives. This Whole, therefore, as thou rememberest, in that it is of all,—in other words, all things, embraced by nature under “Soul” and “World,” are in [perpetual] flux, so varied by the multiform equality of all their forms, that countless kinds of well-distinguished qualities may be discerned, yet with this bond of union, that all should seem as One, and from “One” “All.” III

(4) And if all things in motion desire, not repose, but ever to make known their own proper movement, even this is an aspiration after the Divine Peace of the whole, which preserves all things from falling away of their own accord, and guards the idiosyncrasy and moving life of all moving things unmoved and free from falling, so that the things moved, being at peace amongst themselves, and always in the same condition, perform their own proper functions.

(6) The Providence that regulates all this Makes with its light the heaven forever quiet, Wherein that turns which has the greatest haste. And thither now, as to a site decreed, Bears us away the virtue of that cord Which aims its arrows at a joyous mark. True is it, that as oftentimes the form Accords not with the intention of the art, Because in answering is matter deaf, So likewise from this course doth deviate Sometimes the creature, who the power possesses, Though thus impelled, to swerve some other way, (In the same wise as one may see the fire Fall from a cloud,) if the first impetus Earthward is wrested by some false delight. Thou shouldst not wonder more, if well I judge, At thine ascent, than at a rivulet From some high mount descending to the lowland. Marvel it would be in thee, if deprived Of hindrance, thou wert seated down below, As if on earth the living fire were quiet." Thereat she heavenward turned again her face.

(34) Timaeus: For movement He assigned unto it that which is proper to its body, namely, that one of the seven motions which specially belongs to reason and intelligence; wherefore He spun it round uniformly in the same spot and within itself and made it move revolving in a circle; and all the other six motions He took away and fashioned it free from their aberrations. And seeing that for this revolving motion it had no need of feet, He begat it legless and footless. Such, then, was the sum of the reasoning of the ever-existing God concerning the god

(5) ARISLEUS saith:—Know that the earth is a hill and not a plain, for which reason the Sun does not ascend over all the zones of the earth in a single hour; but if it were flat, the sun would rise in a moment over the whole earth.

Parmenides saith:—Thou hast spoken briefly, O Arisleus!

He answereth:— Is there anything the Master has left us which bears witness otherwise? Yet I testify that God is one, having never engendered or been begotten, and that the head of all things after Him is earth and fire, because fire is tenuous and light, and it rules all things on earth, but the earth, being ponderous and gross, sustains all things which are ruled by fire.

(8) Now: given a light of this degree, remaining in the upper sphere at its appointed station, pure light in purest place, what mode of outflow from it can be conceived possible?

Such a Kind is not so constituted as to flow downwards of its own accord; and there exists in those regions no power to force it down. Again, body in contact with soul must always be very different from body left to itself; the bodily substance of the heavens has that contact and will show that difference.

Besides, the corporeal substance nearest to the heavens would be air or fire: air has no destructive quality; fire would be powerless there since it could not enter into effective contact: in its very rush it would change before its attack could be felt; and, apart from that, it is of the lesser order, no match for what it would be opposing in those higher regions.

Again, fire acts by imparting heat: now it cannot be the source of heat to what is already hot by nature; and anything it is to destroy must as a first condition be heated by it, must be brought to a pitch of heat fatal to the nature concerned.

In sum, then, no outside body is necessary to the heavens to ensure their permanence- or to produce their circular movement, for it has never been shown that their natural path would be the straight line; on the contrary the heavens, by their nature, will either be motionless or move by circle; all other movement indicates outside compulsion. We cannot think, therefore, that the heavenly bodies stand in need of replenishment; we must not argue from earthly frames to those of the celestial system whose sustaining soul is not the same, whose space is not the same, whose conditions are not those which make restoration necessary in this realm of composite bodies always in flux: we must recognise that the changes that take place in bodies here represent a slipping-away from the being and take place at the dictate of a Principle not dwelling in the higher regions, one not powerful enough to ensure the permanence of the existences in which it is exhibited, one which in its coming into being and in its generative act is but an imitation of an antecedent Kind, and, as we have shown, cannot at every point possess the unchangeable identity of the Intellectual Realm.

(1) [Asclepius] Thou speak’st of God, then, O Thrice-greatest one?

[Trismegistus] Not only God, Asclepius, but all things living and inanimate. For ’tis impossible that any of the things that are should be unfruitful. For if fecundity should be removed from all the things that are, it could not be that they should be for ever what they are. I mean that Nature, Sense, and Cosmos, have in themselves the power of being born, and of preserving all things that are born. For either sex is full of procreation; and of each one there is a union, or,—what’s more true,—a unity incomprehensible; which you may rightly call Erōs or Aphroditē, or both [names].

(9) But what again, when the Theologians say, that the unmoved goes forth to all, and is moved? Must we not understand this in a sense befitting God? For we must reverently suppose that He is moved, not as beseems carriage, or change, or alteration, or turning, or local movement, or the straight, or the circular, or that from both (curvative), or the intellectual, or the spiritual, or the physical, but that Almighty God brings into being and sustains everything, and provides in every way for everything; and is present, to all, by the irresistible embrace of all, and by His providential progressions and operations to all existing things. But we must concede to our discourse, to celebrate in a sense becoming God, even movements of God, the immovable. And the straight must be considered (to be) the unswerving and the undeviating progression of the operation, and the production from Himself of the whole; and the curvative--the steady progression and the productive condition; and the circular the same, and the holding together the middle and extremities, which encompass and are encompassed,--and the turning to Him of the things which proceeded from Him.

(11) For of objects that are moved, some are moved by impulse and appearance, as animals; and some by transposition, as inanimate objects. And of things without life, plants, they say, are moved by transposition in order to growth, if we will concede to them that plants are without life. To stones, then, belongs a permanent state. Plants have a nature; and the irrational animals possess impulse and perception, and likewise the two characteristics already specified.

(2) How, therefore, can any terrestrial vapour, which is not elevated five stadia from the earth before it again flows down to the earth, either nourish a circulating and immaterial body, or, in short, produce in it a certain defilement, or any other passion? For it is acknowledged that an etherial body is void of all contrariety, is liberated from all mutation, is entirely pure from the possibility of being transmuted into any thing else, and is perfectly free from a tendency to, and from the middle, because it is either without any tendency, or is convolved in a circle. Hence, it is not possible that bodies, which consist of different powers and motions, which are all-variously changed, and are moved either upwards or downwards, should have any communion of nature or power with celestial bodies, or that any exhalation of the former should be mingled with the latter. As the former, therefore, are entirely separated from the latter, they will not effect any thing in them. For celestial bodies being unbegotten, are not capable of receiving any mutation from generated natures. How, therefore, can the Gods be defiled by such like vapours, who suddenly, as I may say, at one stroke, amputate the vapours ascending from all matter and material bodies?

(22) But suppose that we identify alteration with Motion on the ground that Motion itself results in difference: how then do we proceed to define Motion?

It may roughly be characterized as the passage from the potentiality to its realization. That is potential which can either pass into a Form- for example, the potential statue- or else pass into actuality- such as the ability to walk: whenever progress is made towards the statue, this progress is Motion; and when the ability to walk is actualized in walking, this walking is itself Motion: dancing is, similarly, the motion produced by the potential dancer taking his steps.

In the one type of Motion a new Form comes into existence created by the motion; the other constitutes, as it were, the pure Form of the potentiality, and leaves nothing behind it when once the motion has ceased. Accordingly, the view would not be unreasonable which, taking some Forms to be active, others inactive, regarded Motion as a dynamic Form in opposition to the other Forms which are static, and further as the cause of whatever new Form ensues upon it. To proceed to identify this bodily motion with life would however be unwarrantable; it must be considered as identical only in name with the motions of Intellect and Soul.

That Motion is a genus we may be all the more confident in virtue of the difficulty- the impossibility even- of confining it within a definition.

But how can it be a Form in cases where the motion leads to deterioration, or is purely passive? Motion, we may suggest, is like the heat of the sun causing some things to grow and withering others. In so far as Motion is a common property, it is identical in both conditions; its apparent difference is due to the objects moved.

Is, then, becoming ill identical with becoming well? As motions they are identical. In what respect, then, do they differ? In their substrates? or is there some other criterion?

This question may however be postponed until we come to consider alteration: at present we have to discover what is the constant element in every motion, for only on this basis can we establish the claim of Motion to be a genus.

Perhaps the one term covers many meanings; its claim to generic status would then correspond to that of Being.

As a solution of the problem we may suggest that motions conducing to the natural state or functioning in natural conditions should perhaps, as we have already asserted, be regarded as being in a sense Forms, while those whose direction is contrary to nature must be supposed to be assimilated to the results towards which they lead.

But what is the constant element in alteration, in growth and birth and their opposites, in local change? What is that which makes them all motions? Surely it is the fact that in every case the object is never in the same state before and after the motion, that it cannot remain still and in complete inactivity but, so long as the motion is present, is continually urged to take a new condition, never acquiescing in Identity but always courting Difference; deprived of Difference, Motion perishes.

Thus, Difference may be predicated of Motion, not merely in the sense that it arises and persists in a difference of conditions, but in the sense of being itself perpetual difference. It follows that Time, as being created by Motion, also entails perpetual difference: Time is the measure of unceasing Motion, accompanying its course and, as it were, carried along its stream.

In short, the common basis of all Motion is the existence of a progression and an urge from potentiality and the potential to actuality and the actual: everything which has any kind of motion whatsoever derives this motion from a pre-existent potentiality within itself of activity or passivity.