_a._ The sensuous perceptible substance is that in which the matter is still distinguished from the efficient form. Hence this substance is finite; for the separation and externality of form and matter are precisely what constitute the nature of the finite. Sensuous substance, says Aristotle (Metaph. XII. 2), involves change, but in such a way that it passes over into the opposite; the opposites disappear in one another, and the third beyond these opposites, that which endures, the permanent in this change, is matter. Now the leading categories of change which Aristotle names are the four differences, in regard to the What (κατὰ τὸ τί), or in regard to quality (ποιόν), or in regard to quantity (ποσόν), or in regard to place where (ποῦ). The first change is the origination and decay of simple determinate Being (κατὰ τόδε); the second change is that of the further qualities (κατὰ τὸ πάθος); the third, increase and diminution; the fourth, motion. Matter is the dead substance on which take place the changes which matter passes through. “The change itself is from potential into actual existence; possible whiteness transforms itself into actual whiteness. Thus things do not arise casually out of nothing, but all arises out of what exists, though it exists only in potentiality, not in actuality.” The possible is thus really a general implicit existence, which brings about these determinations, without producing one out of the other. Matter is thus simple potentiality, which, however, is placed in opposition to itself, so that a thing in its actuality only becomes that which its matter was also in potentiality. There are thus three moments posited: matter, as the general substratum of change, neutral in respect of what is different (ἐξ οὗ); the opposed determinations of form, which are negative to each other as that which is to be abrogated and that which is to be posited (τι and εἴς τι); the first mover (ὑφ̓ οὗ), pure activity (Metaph. VII. 7; IX. 8; XII. 3).[89] But activity is the unity of form and matter; how these two are in the other, Aristotle does not, however, further explain. Thus in sensuous substance there appears the diversity of the moments, though not as yet their return into themselves; but activity is the negative which ideally contains in itself the opposite, therefore that also which is about to be.
_b._ A higher kind of substance, according to Aristotle (Metaph. IX. 2; VII. 7; XII. 3), is that into which activity enters, which already contains that which is about to be. This is understanding, absolutely determined, whose content is the aim which it realizes through its activity, not merely changing as does the sensuous form. For the soul is essentially actuality, a general determination which posits itself; not only formal activity, whose content comes from somewhere else. But while the active posits its content in reality, this content yet remains the same; there is an activity present which is different from matter, although substance and activity are allied. Thus here we still have a matter which understanding demands as its hypothesis. The two extremes are matter as potentiality, and thought as efficiency: the former is the passive universal, and the latter the active universal; in sensuous substance the active is, on the contrary, still quite different from matter. In these two moments themselves change does not take place, for they are the implicit universal in opposed forms.
_c._ The highest point is, however, that in which potentiality, activity and actuality are united; the absolute substance which Aristotle (Metaph. XII. 6, 7; IX. 8), defines in general as being the absolute (ἀϊδιον), the unmoved, which yet at the same time moves, and whose essence is pure activity, without having matter. For matter as such is passive and affected by change, consequently it is not simply one with the pure activity of this substance. Here as elsewhere we certainly see an instance of merely denying a predicate, without saying what its truth is; but matter is nothing else than that moment of unmoved Being. If in later times it has seemed something new to define absolute Being as pure activity, we see that this arises from ignorance as to the Aristotelian conception. But the Schoolmen rightly looked upon this as the definition of God, since they define God as _actus purus_; and higher idealism than this there is none. We may also express this as follows: God is the Substance which in its potentiality has reality also unseparated from it; therein potentiality is not distinguished from form, since it produces from itself the determinations of its content. In this Aristotle breaks away from Plato, and for this reason controverts number, the Idea, and the universal, because if this, as inert, is not defined as identical with activity, there is no movement. Plato’s inert Ideas and numbers thus bring nothing into reality; but far different is the case with the Absolute of Aristotle, which in its quiescence is at the same time absolute activity.
Aristotle further says on this subject (Metaph. XII. 6): “It may be that what has potentiality is not real; it is of no avail therefore to make substances eternal, as the idealists do, if they do not contain a principle which can effect change. And even this is insufficient, if it is not active, because in that case there is no change. Yea, even if it were active, but its substance only a potentiality, there would be in it no eternal movement, for it is possible that what is according to potentiality may not exist. We must therefore have a principle whose substance must be apprehended as activity.” Thus in mind energy is substance itself. “But here a doubt seems to spring up. For all that is active seems to be possible, but all that is possible does not seem to energize, so that potentiality seems to be antecedent,” for it is the universal. “But if this were the case, no one of the entities would be in existence, for it is possible that a thing may possess a capacity of existence, though it has never yet existed. But energy is higher than potentiality. We must thus not assert, as theologians would have us do, that in the eternal ages there was first chaos or night” (matter), “nor must we say with natural philosophers that everything existed simultaneously. For how could the First be changed, if nothing in reality were cause? For matter does not move itself, it is the Master who moves it. Leucippus and Plato accordingly say that motion has always existed, but they give no reason for the assertion.” Pure activity is, according to Aristotle (Metaph. IX. 8), before potentiality, not in relation to time, but to essence. That is to say, time is a subordinate moment, far removed from the universal; for the absolute first Being is, as Aristotle says at the end of the sixth chapter of the twelfth book, “that which in like activity remains always identical with itself.” In the former assumption of a chaos and so on, an activity is posited which has to do with something else, not with itself, and has therefore a pre-supposition; but chaos is only bare possibility.
That which moves in itself, and therefore, as Aristotle continues (Metaph. XII. 7), “that which has circular motion;” is to be posited as the true Being, “and this is evident not merely from thinking reason, but also from the fact itself.” From the definition of absolute Being as imparting motion, as bringing about realization, there follows that it exists in objectivity in visible nature. As the self-identical which is visible, this absolute Being is “the eternal heavens.” The two modes of representing the Absolute are thus thinking reason and the eternal heavens. The heavens are moved, but they also cause movement. Since the spherical is thus both mover and moved, there is a centre-point which causes movement but remains unmoved, and which is itself at the same time eternal and a substance and energy.[90] This great definition given by Aristotle of absolute Being as the circle of reason which returns into itself, is of the same tenor as modern definitions; the unmoved which causes movement is the Idea which remains self-identical, which, while it moves, remains in relation to itself. He explains this as follows: “Its motion is determined in the following manner. That moves which is desired and thought, whereas itself it is unmoved, and the original of both is the same.” That is the end whose content is the desire and thought; such an end is the Beautiful or the Good. “For the thing that is desired is that which appears beautiful” (or pleases): “whose first” (or end), “on which the will is set, is what is beautiful. But it is rather the case that we desire it because it appears beautiful, than that it appears beautiful because we desire it.” For if that were so, it would be simply posited by activity, but it is posited independently, as objective Being, through which our desire is first awakened. “But thought is the true principle in this, for thought is moved only by the object of thought. But the intelligible” (we scarcely believe our eyes) “is essentially the other co-element (συστοιχία)”[91] namely, that which is posited as objective, as absolutely existent thought, “and the substance of this other element is the first; but the first substance is simple pure activity. Such are the Beautiful and the Good, and the first is ever the absolutely best or the best possible. But the Notion shows that the final cause belongs to the unmoved. What is moved may also subsist in a different manner. Motion (φορά) is the first change; the first motion, again, is circular motion, but this is due to the above cause.” Therefore, according to Aristotle, the Notion, _principium cognoscendi_, is also that which causes movement, _principium essendi_; he expresses it as God, and shows the relation of God to the individual consciousness. “The First Cause is necessary. But the term necessary has three meanings: first what is accomplished by violence, because it goes contrary to one’s inclination (παρὰ τὴν ὁρμήν); secondly, that without which the Good does not subsist; thirdly, that which can exist in no other way than it does, but involves absolute existence. On such a principle of the unmoved the heavens depend and the whole of nature”—the visible that is eternal, and the visible that changes. This system is ever-enduring. “But to us” as individuals, “there is granted, for a short time only, a sojourn therein of surpassing excellence. For the system continues ever the same, but for us that is impossible. Now this activity is in its very self enjoyment, and therefore vigilance, exercise of the senses, thinking in general, are most productive of enjoyment; and for the same reason hopes and memories bring pleasure. But thinking, in its pure essence, is a thinking of that which is absolutely the most excellent;” the thought is for itself absolute end. The difference and contradiction in activity and the abrogation of the same, Aristotle expresses thus: “But thought thinks itself by participation (μετάληψιν) in that which is thought, but thought becomes thought by contact and apprehension, so that thought and the object of thought are the same.” Thought, as being the unmoved which causes motion, has an object, which, however, becomes transformed into activity, because its content is itself something thought, _i.e._ a product of thought, and thus altogether identical with the activity of thinking. The object of thought is first produced in the activity of thinking, which in this way separates the thought as an object. Hence, in thinking, that which is moved and that which moves are the same; and as the substance of what is thought is thought, what is thought is the absolute cause which, itself unmoved, is identical with the thought which is moved by it; the separation and the relation are one and the same. The chief moment in Aristotle’s philosophy is accordingly this, that the energy of thinking and the object of thought are the same; “for thought is that which is receptive of objects of perception and the existent. When in possession of these it is in a condition of activity (ἐνεργεῖ δὲ ἔχων); and thus all this” operation by which it thinks itself, “is more divine than the divine possession which thinking reason supposes itself to have,”—the content of thought. It is not the object of thought that is the more excellent, but the very energy of thinking; the activity of apprehension brings that to pass which appears as something that is being apprehended. “Speculation (ἡ θεωρία) is thus the most pleasing and the best. If then God has eternally subsisted in such surpassing excellence as for a limited time pertains to us” (in whom this eternal Thought, which is God Himself, occurs only as a particular condition), “He is worthy of admiration; if He possesses it in a more eminent degree, His nature is still more admirable. But this is His mode of subsistence. Life is also inherent in Him, for the activity of thought is life. But He constitutes this efficient power; essential energy belongs to God as His most excellent and eternal life. We therefore say that with God there is life perfect and everlasting.” From this substance Aristotle moreover excludes magnitude.
We in our way of speaking designate the Absolute, the True, as the unity of subjectivity and objectivity, which is therefore neither the one nor the other, and yet just as much the one as the other; and Aristotle busied himself with these same speculations, the deepest forms of speculation even of the present day, and he has expressed them with the greatest definiteness. With Aristotle it is thus no dry identity of the abstract understanding that is indicated, for he distinguishes subjective and objective precisely and decisively. Not dead identity such as this, but energy, is for him what is most to be reverenced, God. Unity is thus a poor, unphilosophic expression, and true Philosophy is not the system of identity; its principle is a unity which is activity, movement, repulsion, and thus, in being different, is at the same time identical with itself. If Aristotle had made the jejune identity of understanding, or experience, his principle, he would never have risen to a speculative Idea like this, wherein individuality and activity are placed higher than universal potentiality. Thought, as the object of thought, is nothing else than the absolute Idea regarded as in itself, the Father; yet this First and unmoved, as distinguished from activity, is, as absolute, simply activity, and is first through this activity set forth as true. In what he teaches respecting the soul we shall find Aristotle recurring to this speculative thought; but to Aristotle it is again an object, like other objects, a kind of condition which he separates from the other conditions of the soul which he understands empirically, such as sleep, or weariness. He does not say that it alone is truth, that all is summed up in Thought, but he says it is the first, the strongest, the most honourable. We, on the other hand, say that Thought, as that which relates to itself, has existence, or is the truth; that Thought comprehends the whole of Truth, even, though we ordinarily represent to ourselves sensation and so on, besides thought, as having reality. Thus, although Aristotle does not express himself in modern philosophic language, he has yet throughout the same fundamental theory; he speaks not of a special kind of reason, but of the universal Reason. The speculative philosophy of Aristotle simply means the direction of thought on all kinds of objects, thus transforming these into thoughts; hence, in being thoughts, they exist in truth. The meaning of this is not, however, that natural objects have thus themselves the power of thinking, but as they are subjectively thought by me, my thought is thus also the Notion of the thing, which therefore constitutes its absolute substance. But in Nature the Notion does not exist explicitly as thought in this freedom, but has flesh and blood, and is oppressed by externalities; yet this flesh and blood has a soul, and this is its Notion. The ordinary definition of truth, according to which it is “the harmony of the conception with the object,” is certainly not borne out by the conception; for when I represent to myself a house, a beam, and so on, I am by no means this content, but something entirely different, and therefore very far from being in harmony with the object of my conception. It is only in thought that there is present a true harmony between objective and subjective; that constitutes me. Aristotle therefore finds himself at the highest standpoint; nothing deeper can we desire to know, although he has always the appearance of making ordinary conceptions his starting-point.
Aristotle (Metaph. XII. 9) now solves many other doubtful questions, for instance, whether thought is compound, and whether science is the object of science itself. “Some further doubts arise as to thought (νοῦς), which seems to be of all things the most divine; but it is only with difficulty that we can conceive under what conditions (πῶς δ̓ ἔχων) it is a thing of this sort. When it thinks of nothing, but is in a state like that of a sleeper, what constitutes its superiority? And when it thinks, but something else is dominant all the time (ἄλλο κύριον), that which is its substance is not thought (νόησις), but a potentiality;” it would not be in eternal activity. “In this way it would not be the highest substance; for it is” (active) “thought (τὸ νοεῖν) that gives it its high rank. If now, further, thought or thinking is its substance, what does it think? Itself or another? And if another, is it always the same, or something different? Does it also not make a difference, whether it thinks of what is beautiful or what is casual? In the first place, if thought is not thinking, but only the power to think, continuous thinking would be laborious for it,” for every power wears itself out. “In the next place, something else would be more excellent than thought, namely that which is thought (νοούμενον); and thinking and thought (τὸ νοεῖν καὶ ἡ νόησις) will be present to the mind in understanding what is most inferior. As this is to be avoided (in the same way that it is better not to see some things than to see them), thinking would not constitute the best. Thought is therefore this, to think itself, because it is the most excellent; and it is the thinking, which is the thinking of thinking. For understanding and sensation and opinion and deliberation seem always to have an object other than themselves, and to be their own objects only in a secondary sense. Further, if thinking and being thought of are different, in relation to which of the two is the Good inherent in thought? For the Notion[92] of thinking and that of the object of thought are not the same. Or, in the case of some things, does the science itself constitute that which is the object of science? In what is practical the thing is the immaterial substance and the determination of the end (ἡ οὐσία καὶ τὸ τί ἦν εἶναι), and in what is theoretical it is the reason and the thinking. As therefore thought and the object of thought are not different, these opposites, so far as they involve no connection with matter, are the same thing, and there is only a thought of the thing thought of.” Reason which thinks itself, is the absolute end or the Good, for it only exists for its own sake. “There still remains a doubt whether that which thinks is of composite nature or not; for it might undergo change in the parts of the whole. But the Good is not in this or that part, for it is the best in the universe, as distinguished from it. In this way the Thought which is its own object subsists to all eternity.”
As this speculative Idea, which is the best and most free, is also to be seen in nature, and not only in thinking reason, Aristotle (Metaph. XII. 8) in this connection passes on to the visible God, which is the heavens. God, as living God, is the universe; and thus in the universe God, as living God, shows Himself forth. He comes forth as manifesting Himself or as causing motion, and it is in manifestation alone that the difference between the cause of motion and that which is moved comes to pass. “The principle and the first cause of that which is, is itself unmoved, but brings to pass the original and eternal and single motion,” that is, the heaven of the fixed stars. “We see that besides the simple revolution of the universe, which is brought about by the first unmoved substance, there are other eternal motions, those of the planets.” We must not, however, enter into further details on this subject.
Regarding the organization of the universe in general, Aristotle says (Metaph. XII. 10), “We must investigate in what manner the nature of the whole has within it the Good and the Best; whether as something set apart and absolute, or as an order, or in both ways, as in the case of an army. For the good condition of an army depends upon the order enforced, as much as on the general, and the general is the cause of the army’s good condition in all the greater degree from the fact of the order being through him, and not from his being through the order. All things are co-ordinated in a certain way, but not all in the same way: take, for example, animals which swim, and those which fly, and plants; they are not so constituted that one of them is not related to another, but they stand in mutual relations. For all are co-ordinated into one system just as in a house it is by no means permitted to the free inmates to do freely whatever they like, but all that they do, or the most of it, is done according to orderly arrangement. By slaves and animals, on the contrary, little is done for the general good, but they do much that is casual. For the principle of each is his own nature. In the same way it is necessary that all should attain to a position where distinction is drawn” (the seat of judgment) “but there are some things so constituted that all participate in them for the formation of a whole.” Aristotle then goes on to refute some other notions; showing, for instance, the embarrassments into which they fall who make all things proceed from oppositions, and he corroborates, on the other hand, the unity of the principle by quoting Homer’s line (Iliad II. 204): “It is not good that many govern; let one alone bear rule.”
2. PHILOSOPHY OF NATURE.
Amongst the special sciences treated by Aristotle, the Physics is contained in a whole series of physical treatises, which form a tolerably complete system of what constitutes the Philosophy of Nature in its whole extent. We shall try to give their general plan. Aristotle’s first work is his Treatise, in eight books, on Physics, or on the Principles (φυσικὴ ἀκρόασις ἢ περὶ ἀρχῶν). In this he deals, as is fitting, with the doctrine of the Notion of nature generally, with movement, and with space and time. The first manifestation of absolute substance is movement, and its moments are space and time; this conception of its manifestation is the universal, which realizes itself first in the corporeal world, passing into the principle of separation. Aristotle’s Physics is what for present physicists would, properly speaking, be the Metaphysics of Nature; for our physicists only say what they have seen, what delicate and excellent instruments they have made, and not what they have thought. This first work by Aristotle is followed by his treatises concerning the Heavens, which deal with the nature of body and the first real bodies, the earth and heavenly bodies in general, as also with the general abstract relation of bodies to one another through mechanical weight and lightness, or what we should call attraction; and finally, with the determination of abstract real bodies or elements. Then follow the treatises on Production and Destruction, the physical process of change, while formerly the ideal process of movement was considered. Besides the physical elements, moments which are only posited in process, as such, now enter in: for instance, warmth, cold, &c. Those elements are the real existent facts, while these determinations are the moments of becoming or of passing away, which exist only in movement. Then comes the Meteorology; it represents the universal physical process in its most real forms. Here particular determinations appear, such as rain, the saltness of the sea, clouds, dew, hail, snow, hoar-frost, winds, rainbows, boiling, cooking, roasting, colours, &c. On certain matters, such as the colours, Aristotle wrote particular treatises. Nothing is forgotten, and yet the presentation is, on the whole, empiric. The book On the Universe, which forms the conclusion, is said not to be genuine; it is a separate dissertation, addressed to Alexander, which contains in part the doctrine of the universality of things, a doctrine found already in the other treatises; hence this book does not belong to this series.
From this point Aristotle proceeds to organic nature, and here his works not only contain a natural history, but also a physiology and anatomy. To the anatomy pertain his works on the Locomotion of Animals, and on the Parts of Animals. He deals with physiology in the works on the Generation of Animals, on the common Movement of Animals; and then he comes to the distinction between Youth and Age, Sleeping and Waking, and treats of Breathing, Dreaming, the Shortness and Length of Life, &c., all of which he deals with partly in an empiric, and partly in a more speculative manner. Finally, there comes the History of Animals, not merely as a history of Nature, but also as the history of the animal in its entirety—what we may call a kind of physiologico-anatomical anatomy. There is likewise a botanical work On Plants (περὶ φυτῶν) which is ascribed to him. Thus we here find natural philosophy in the whole extent of its outward content.
As regards this plan, there is no question that this is not the necessary order in which natural philosophy or physics must be treated. It is long since physics adopted in its conception the form and tendency derived from Aristotle, of deducing the parts of the science from the whole; and thus even what is not speculative still retains this connection as far as outward order goes. This is plainly to be preferred to the arrangement in our modern text-books, which is a wholly irrational succession of doctrines accidentally put together, and is undoubtedly more suitable to that method of contemplating nature, which grasps the sensuous manifestation of nature quite irrespective of sense or reason. Physics before this contained some metaphysics, but the experience which was met with in endeavouring unsuccessfully to work it out, determined the physicists, so far as possible, to keep it at a distance, and to devote their attention to what they call experience, for they think that here they come across genuine truth, unspoiled by thought, fresh from the hand of nature; it is in their hands and before their faces. They can certainly not dispense with the Notion, but through a kind of tacit agreement they allow certain conceptions, such as forces, subsistence in parts, &c., to be valid, and make use of these without in the least knowing whether they have truth and how they have truth. But in regard to the content they express no better the truth of things, but only the sensuous manifestation. Aristotle and the ancients understand by physics, on the other hand, the comprehension of nature—the universal; and for this reason Aristotle also calls it the doctrine of principles. For in the manifestation of nature this distinction between the principle and what follows it, manifestation, really commences, and it is abrogated only in genuine speculation. Yet if, on the one hand, what is physical in Aristotle is mainly philosophic and not experimental, he yet proceeded in his Physics in what may be called an empiric way. Thus, as it has been already remarked of the Aristotelian philosophy in general that the different parts fall into a series of independently determined conceptions, so we find that this is the case here also; hence an account can only be given of a part of them. One part is not universal enough to embrace the other part, for each is independent. But that which follows, and which has in great measure reference to what is individual, no longer comes under the dominion of the Notion, but becomes a superficial suggestion of reasons, and an explanation from the proximate causes, such as we find in our physics.
In regard to the general conception of nature, we must say that Aristotle represents it in the highest and truest manner. For in the Idea of nature Aristotle (Phys. II. 8) really relies on two determinations: the conception of end and the conception of necessity. Aristotle at once grasps the whole matter in its principles, and this constitutes the old contradiction and divergence of view existing between necessity (_causæ efficientes_) and end (_causæ finales_), which we have inherited. The first mode of consideration is that in accordance with external necessity, which is the same as chance—the conception that all that pertains to nature is determined from without by means of natural causes. The other mode of consideration is the teleological, but conformity to end is either inward or outward, and in the more recent culture the latter has long retained the supremacy. Thus men vibrate in their opinion between these two points of view, seek external causes, and war against the form of an external teleology which places the end outside of nature. These determinations were known to Aristotle, and he thoroughly investigates them and considers what they are and mean. Aristotle’s conception of nature is, however, nobler than that of to-day, for with him the principal point is the determination of end as the inward determinateness of natural things. Thus he comprehended nature as life, _i.e._ as that which has its end within itself, is unity with itself, which does not pass into another, but, through this principle of activity, determines changes in conformity with its own content, and in this way maintains itself therein. In this doctrine Aristotle has before his eyes the inward immanent end, to which he considers necessity an external condition. Thus, on the one hand, Aristotle determines nature as the final cause, which is to be distinguished from what is luck or chance; it is thus opposed by him to what is necessary, which it also contains within itself; and then he considers how necessity is present in natural things. In nature we usually think of necessity first, and understand as the essentially natural that which is not determined through end. For long men thought that they determined nature both philosophically and truly in limiting it to necessity. But the aspect of nature has had a stigma removed from it, because, by means of its conformity to the end in view, it is elevated above the commonplace. The two moments which we have considered in substance, the active form and matter, correspond with these two determinations.
We must first consider the conception of adaptation to end as the ideal moment in substance. Aristotle begins (Phys. II. 8) with the fact that the natural is the self-maintaining, all that is difficult is its comprehension. “The first cause of perplexity is, what hinders nature from not operating for the sake of an end, and because it is better so to operate, but” being, for example, “like Jupiter, who rains, not that the corn may grow, but from necessity. The vapour driven upwards cools, and the water resulting from this cooling falls as rain, and it happens that the corn is thereby made to grow. In like manner, if the corn of any one is destroyed, it does not rain for the sake of this destruction, but this is an accidental circumstance.” That is to say, there is a necessary connection which, however, is an external relation, and this is the contingency of the cause as well as of the effect. “But if this be so,” Aristotle asks, “what hinders us from assuming that what appears as parts” (the parts of an animal, for instance) “may thus subsist in nature, too, as contingent? That, for example, the front teeth are sharp and adapted for dividing, and that the back teeth, on the contrary, are broad and adapted for grinding the food in pieces, may be an accidental circumstance, not necessarily brought about for these particular ends. And the same is true with respect to the other parts of the body which appear to be