(9) Accordingly we must first take the genus, in which are the points that are nearest those above; and after this the next difference. And the succession of differences, when cut and divided, completes the "What it is." There is no necessity for expressing all the differences of each thing, but those which form the species.

(18) Know, therefore, generally, my son, that all that is in Cosmos is being moved for increase or for decrease. Now that which is kept moving, also lives; but there is no necessity that that which lives, should be all same. For being simultaneous, the Cosmos, as a whole, is not subject to change, my son, but all its parts are subject unto it; yet naught [of it] is subject to corruption, or destroyed. It is the terms employed that confuse men. For 'tis not genesis that constituteth life, but 'tis sensation; it is not change that constituteth death, but 'tis forgetfulness. Since, then, these things are so, they are immortal all - Matter, [and] Life, [and] Spirit, Mind [and] Soul, of which whatever liveth, is composed.

(42) For the earthly and corrupt nature has continually laboured from the beginning of its creation to this day to bring forth heavenly forms or shapes in the earth, as also in man and beasts; as men very well see that every year new arts are invented and brought to light, which has been constantly so from the beginning to this time.

(11) We divide, therefore, the genus of what is proposed for consideration into the species contained in it; as, in the case of man, we divide animal, which is the genus, into the species that appear in it, the mortal, and the immortal. And thus, by continually dividing those genera that seem to be compound into the simpler species, we arrive at the point which is the subject of investigation, and which is incapable of further division.

(12) For, after dividing "the animal" into mortal and immortal, then into terrestrial and aquatic; and the terrestrial again into those who fly and those who walk; and so dividing the species which is nearest to what is sought, which also contains what is sought, we arrive by division at the simplest species, which contains nothing else, but what is sought alone.

(24) Now in definitions, difference is assumed, which, in the definition, occupies the place of sign. The faculty of laughing, accordingly, being added to the definition of man, makes the whole - a rational, mortal, terrestrial, walking, laughing animal. For the things added by way of difference to the definition are the signs of the properties of things; but do not show the nature of the things themselves. Now they say that the difference is the assigning of what is peculiar; and as that which has the difference differs from all the rest, that which belongs to it alone, and is predicated conversely of the thing, must in definitions be assumed by the first genus as principal and fundamental.

(50) Accordingly I find, that the birth or geniture of nature stands to this day, and generateth itself, just so as it did when it first took its beginning; and whatsoever riseth up in this world, whether men, beasts, trees, herbs, grass, mineral ores, or be it what it will, all riseth up in such a quality, manner and form as it first did; also every life, be it good or bad, taketh its original thus [as it did from the beginning].

(19) Having established our four primary genera, it remains for us to enquire whether each of them of itself alone produces species. And especially, can Being be divided independently, that is without drawing upon the other genera? Surely not: the differentiae must come from outside the genus differentiated: they must be differentiae of Being proper, but cannot be identical with it.

Where then is it to find them? Obviously not in non-beings. If then in beings, and the three genera are all that is left, clearly it must find them in these, by conjunction and couplement with these, which will come into existence simultaneously with itself.

But if all come into existence simultaneously, what else is produced but that amalgam of all Existents which we have just considered ? How can other things exist over and above this all-including amalgam? And if all the constituents of this amalgam are genera, how do they produce species? How does Motion produce species of Motion? Similarly with Stability and the other genera.

A word of warning must here be given against sinking the various genera in their species; and also against reducing the genus to a mere predicate, something merely seen in the species. The genus must exist at once in itself and in its species; it blends, but it must also be pure; in contributing along with other genera to form Substance, it must not destroy itself. There are problems here that demand investigation.

But since we identified the amalgam of the Existents with the particular intellect, Intellect as such being found identical with Being or Substance, and therefore prior to all the Existents, which may be regarded as its species or members, we may infer that the intellect, considered as completely unfolded, is a subsequent.

Our treatment of this problem may serve to promote our investigation; we will take it as a kind of example, and with it embark upon our enquiry.

(92) Timaeus: into one another in all these ways, as they undergo transformation by the loss or by the gain of reason and unreason. And now at length we may say that our discourse concerning the Universe has reached its termination. For this our Cosmos has received the living creatures both mortal and immortal and been thereby fulfilled; it being itself a visible Living Creature embracing the visible creatures, a perceptible God made in the image of the Intelligible, most great and good and fair and perfect in its generation—even this one Heaven sole of its kind.

(3) What, then, can this be, this something in virtue of which we declare the entire divine Realm to be Eternal, everlasting? We must come to some understanding of this perpetuity with which Eternity is either identical or in conformity.

It must at once, be at once something in the nature of unity and yet a notion compact of diversity, or a Kind, a Nature, that waits upon the Existents of that Other World, either associated with them or known in and upon them, they collectively being this Nature which, with all its unity, is yet diverse in power and essence. Considering this multifarious power, we declare it to be Essence in its relation to this sphere which is substratum or underlie to it; where we see life we think of it as Movement; where all is unvaried self-identity we call it Repose; and we know it as, at once, Difference and Identity when we recognize that all is unity with variety.

Then we reconstruct; we sum all into a collected unity once more, a sole Life in the Supreme; we concentrate Diversity and all the endless production of act: thus we know Identity, a concept or, rather, a Life never varying, not becoming what previously it was not, the thing immutably itself, broken by no interval; and knowing this, we know Eternity.

We know it as a Life changelessly motionless and ever holding the Universal content in actual presence; not this now and now that other, but always all; not existing now in one mode and now in another, but a consummation without part or interval. All its content is in immediate concentration as at one point; nothing in it ever knows development: all remains identical within itself, knowing nothing of change, for ever in a Now since nothing of it has passed away or will come into being, but what it is now, that it is ever.

Eternity, therefore- while not the Substratum - may be considered as the radiation of this Substratum: it exists as the announcement of the Identity in the Divine, of that state- of being thus and not otherwise- which characterizes what has no futurity but eternally is.

What future, in fact, could bring to that Being anything which it now does not possess; and could it come to be anything which it is not once for all?

There exists no source or ground from which anything could make its way into that standing present; any imagined entrant will prove to be not alien but already integral. And as it can never come to be anything at present outside it, so, necessarily, it cannot include any past; what can there be that once was in it and now is gone? Futurity, similarly, is banned; nothing could be yet to come to it. Thus no ground is left for its existence but that it be what it is.

That which neither has been nor will be, but simply possesses being; that which enjoys stable existence as neither in process of change nor having ever changed- that is Eternity. Thus we come to the definition: the Life- instantaneously entire, complete, at no point broken into period or part- which belongs to the Authentic Existent by its very existence, this is the thing we were probing for- this is Eternity.

(21) The species then being divided more generically, are characterized by sameness and difference. And then being divided, they are chacterized by the points generically indicated.

(21) The claim of Motion to be established as a genus will depend upon three conditions: first, that it cannot rightly be referred to any other genus; second, that nothing higher than itself can be predicated of it in respect of its essence; third, that by assuming differences it will produce species. These conditions satisfied, we may consider the nature of the genus to which we shall refer it.

Clearly it cannot be identified with either the Substance or the Quality of the things which possess it. It cannot, further, be consigned to Action, for Passivity also comprises a variety of motions; nor again to Passivity itself, because many motions are actions: on the contrary, actions and passions are to be referred to Motion.

Furthermore, it cannot lay claim to the category of Relation on the mere ground that it has an attributive and not a self-centred existence: on this ground, Quality too would find itself in that same category; for Quality is an attribute and contained in an external: and the same is true of Quantity.

If we are agreed that Quality and Quantity, though attributive, are real entities, and on the basis of this reality distinguishable as Quality and Quantity respectively: then, on the same principle, since Motion, though an attribute has a reality prior to its attribution, it is incumbent upon us to discover the intrinsic nature of this reality. We must never be content to regard as a relative something which exists prior to its attribution, but only that which is engendered by Relation and has no existence apart from the relation to which it owes its name: the double, strictly so called, takes birth and actuality in juxtaposition with a yard's length, and by this very process of being juxtaposed with a correlative acquires the name and exhibits the fact of being double.

What, then, is that entity, called Motion, which, though attributive, has an independent reality, which makes its attribution possible- the entity corresponding to Quality, Quantity and Substance?

But first, perhaps, we should make sure that there is nothing prior to Motion and predicated of it as its genus.

Change may be suggested as a prior. But, in the first place, either it is identical with Motion, or else, if change be claimed as a genus, it will stand distinct from the genera so far considered: secondly, Motion will evidently take rank as a species and have some other species opposed to it- becoming, say- which will be regarded as a change but not as a motion.

What, then, is the ground for denying that becoming is a motion? The fact, perhaps, that what comes to be does not yet exist, whereas Motion has no dealings with the non-existent. But, on that ground, becoming will not be a change either. If however it be alleged that becoming is merely a type of alteration or growth since it takes place when things alter and grow, the antecedents of becoming are being confused with becoming itself. Yet becoming, entailing as it does these antecedents, must necessarily be a distinct species; for the event and process of becoming cannot be identified with merely passive alteration, like turning hot or white: it is possible for the antecedents to take place without becoming as such being accomplished, except in so far as the actual alteration has "come to be"; where, however, an animal or a vegetal life is concerned, becoming takes place only upon its acquisition of a Form.

The contrary might be maintained: that change is more plausibly ranked as a species than is Motion, because change signifies merely the substitution of one thing for another, whereas Motion involves also the removal of a thing from the place to which it belongs, as is shown by locomotion. Even rejecting this distinction, we must accept as types of Motion knowledge and musical performance- in short, changes of condition: thus, alteration will come to be regarded as a species of Motion- namely, motion displacing.

(4) But the same is superessentially everlasting, inconvertible, abiding in itself, always being in the same condition and manner; present to all in the same manner, and itself by itself, upon itself, firmly and purely fixed in the most beautiful limits of the superessential sameness, without changing, without falling, without swerving, unalterable, unmingled, immaterial, most simplex, self-sufficient, without increase, without diminution, unoriginated, not as not yet come into being, or unperfected, or not having become from this, or that, nor as being in no manner of way whatever, but as all unoriginated, and absolutely unoriginated, and ever being; and being self-complete, and being the same by itself, and differentiated by itself in one sole and same form; and shedding sameness from itself to all things adapted to participate in It; and assigning things different to those different; abundance and cause of identity, preholding identically in itself even things contrary, as beseems the One and unique Cause, surpassing the whole identity.

(4) [Thus] there begins their living and their growing wise, according to the fate appointed by the revolution of the Cyclic Gods, and their deceasing for this end. And there shall be memorials mighty of their handiworks upon the earth, leaving dim trace behind when cycles are renewed. For every birth of flesh ensouled, and of the fruit of seed, and every handiwork, though it decay, shall of necessity renew itself, both by the renovation of the Gods and by the turning-round of Nature's rhythmic wheel. For that whereas the Godhead is Nature's ever-making-new-again the cosmic mixture, Nature herself is also co-established in that Godhead.

(27) Though indeed they shall be changed at the end of this time, when good and evil shall be separated. So in like manner angels and men, in the [particular] virtue of nature, out of which they had gotten their first beginning, shall subsist in God eternally.

(45) Nature laboureth with the utmost diligence in its power to produce heavenly figures, shapes or forms; as we see, in men, beasts, fowls and worms, as also in the increase or growth of the earth, that all things are done, shew and appear most perfectly and ingeniously.

(26) We may now take the various specific types of Motion, such as locomotion, and once again enquire for each one whether it is not to be divided on the basis of direction, up, down, straight, circular- a question already raised; whether the organic motion should be distinguished from the inorganic- they are clearly not alike; whether, again, organic motions should be subdivided into walking, swimming and flight.

Perhaps we should also distinguish, in each species, natural from unnatural motions: this distinction would however imply that motions have differences which are not external. It may indeed be the case that motions create these differences and cannot exist without them; but Nature may be supposed to be the ultimate source of motions and differences alike.

Motions may also be classed as natural, artificial and purposive: "natural" embracing growth and decay; "artificial" architecture and shipbuilding; "purposive" enquiry, learning, government, and, in general, all speech and action.

Again, with regard to growth, alteration and birth, the division may proceed from the natural and unnatural, or, speaking generally, from the characters of the moved objects.

(22) For each of the species is either an essence; as when we say, Some substances are corporeal and some incorporeal; or how much, or what relation, or where, or when, or doing, or suffering.

(7) Hence, too, the errant spheres, being moved contrarily to the inerrant one, are moved by one another by mutual contrariety, [and also] by the spable one through contrariety itself. And this can otherwise not be. The Bears up there , which neither set nor rise, think'st thou they rest or move? A: They move, Thrice-greatest one. H: And what their motion, my Asclepius? A: Motion that turns for ever round the same. H: But revolution - motion around same - is fixed by rest. For "round-the-same" doth stop "beyond-same". "Beyond-same" then, being stopped, if it be steadied in "round-same" - the contrary stands firm, being rendered ever stable by its contrariety.

(27) Accordingly, while the definition is explanatory of the essence of the thing, it is incapable of accurately comprehending its nature. By means of the principal species, the definition makes an exposition of the essence, and almost has the essence in the quality.