Aristotle then shows (De C\nlo, II. I; I. 3) that “the whole heavens neither arose nor can pass away, for they are one and eternal: they neither have beginning nor end in eternal time, for they contain infinite time shut up within them.” All the other ideas are sensuous which try to speak of essential reality, and in them there always is that present which they think they have excluded. For when they assert a vacuum before the beginning of generation, this is the quiescent, self-identical, i.e. the eternal matter, which is thus already established before origination; they will not allow that before origination nothing exists. But in fact a thing does not exist before its origination, i.e. in movement there is something to move, and where reality is, there is motion. They do not, however, bring together that vacuum, the self-identical, the un-originated matter and this nothing. “That which has this absolute circular movement is neither heavy nor light; for the heavy is what moves downwards, and the light what moves upwards.” In modern physics the heavenly bodies, on the other hand, are endowed with weight, and seek to rush into the sun, but cannot do so on account of another force. “It is indestructible and ungenerated, without decrease or increase, without any change. It is different from earth, fire, air and water; it is what the ancients called ether, as the highest place, from its continuous course (ἀεὶ θεῖν) in infinite time.” This ether thus appears to be eternal matter which does not, however, take such a definite form, but which remains as it is, just as the heavens do in our conception, although here the juxtaposition begins ever to strike us more forcibly.
Aristotle (De C\nlo, III. 6) shows further that the elements do not proceed from one body, but from one another; for in generation they neither proceed from what is incorporeal, nor from what is corporeal. In the first case they would have sprung from the vacuum, for the vacuum is the immediate incorporeal; but in that case the vacuum must have existed independently as that in which determinate corporeality arose. But neither do the elements arise from a corporeal, for else this body itself would be a corporeal element before the elements. Thus it only remains that the elements must spring from one another. Regarding this we must remark that Aristotle understands by origination, actual origination—not the transition from the universal to the individual, but the origination of one determinate corporeal, not from its principle, but from the opposite as such. Aristotle does not consider the universal as it contains the negative within it; else the universal would be the absolute matter whose universality, as negativity, is set forth, or is real.
From this point Aristotle comes (De C\nlo, IV. I-5) to a kind of deduction of the elements, which is noteworthy. He shows that there must be four of them, in the following way—because he starts from the fundamental conceptions of weight and of lightness, or what we should call attraction and centrifugal force. The corporeal, he says, in its motion is neither light nor heavy, and, indeed, it is not only relative but also absolute. The relatively light and heavy is what, while equal in volume, descends more slowly or quickly. Absolute lightness goes up to the extremity of the heavens, absolute weight down into the middle. These extremes are fire and earth. Between these there are mediums, other than they, which relate to one another like them; and these are air and water, the one of which has weight, and the other lightness, but only relatively. For water is suspended under everything except earth, and air over everything except fire. “Hence,” Aristotle concludes, “there now are these four matters, but they are four in such a way that they have one in common; more particularly, because they arise out of one another, but exist as different.” Yet it is not the ether that Aristotle designates as this common matter. We must in this regard remark that however little these first determinations may be exhaustive, Aristotle is still far further on than the moderns, since he had not the conception of elements which prevails at the present time, according to which the element is made to subsist as simple. But any such simple determination of Being is an abstraction and has no reality, because such existence would be capable of no motion and change; the element must itself have reality, and it thus is, as the union of opposites, resolvable. Aristotle hence makes the elements, as we have already seen with those who went before (Vol. I., pp. 181, 182; 290-293; 336), arise out of one another and pass into one another; and this is entirely opposed to our Physics, which understands by elements an indelible, self-identical simplicity only. Hence men are wonderfully discerning in reproaching us for calling water, air, &c., elements! Nor yet in the expression “neutrality” have the modern physicists been able to grasp a universality conceived of as a unity, such as Aristotle ascribes to the elements; in fact, however, the acid which unites with a base is no longer, as is asserted, present within it as such. But however removed Aristotle may be from understanding simplicity as an abstraction, just as little does he recognize here the arid conception of consisting of parts. Quite the contrary. He strives enough against this, as, for instance, in relation to Anaxagoras (De C\nl. III. 4).
I shall further mention the moments of the real process in relation to motion, in which Aristotle finally passes on (De gen. et corr. II. 2-4) to the “principles of perceptible body”; we here see the elements in process, as formerly in their restful determinateness. Aristotle excludes the relations which concern sight, smell, &c., and brings forward the others as being those which are of sensible weight or lightness. He gives as these fundamental principles—warmth and cold, dryness and moisture; they are the sensible differences for others, while weight and lightness are different for themselves. Now in order to prepare for the transition of the elements into sensible relations, Aristotle says: “Because there are those four principles, and four things have properly six relations to one another, but the opposite cannot here be connected (the moist cannot be connected with the dry, or the warm with the cold), there are four connections of these principles, warm and dry, warm and moist, cold and moist, cold and dry. And these connections follow those first elements, so that thus fire is warm and dry, air warm and moist (vapour), water cold and moist, earth cold and dry.” From this Aristotle now makes the reciprocal transformation of the elements into one another comprehensible thus: Origination and decay proceed from the opposite and into the opposite. All elements have a mutual opposite; each is as non-being to the Being of the other, and one is thus distinguished from the other as actuality and capacity. Now amongst these some have an equal part in common; fire and water, for example, have warmth; thus if in fire dryness were overcome by moisture, out of fire air would arise. On the contrary, as regards those which have nothing in common with one another, like earth, which is cold and dry, and air, which is warm and moist, the transition goes more slowly forward. The transition of all elements into one another, the whole process of nature, is thus to Aristotle the constant rotation of their changes. This is unsatisfactory, because neither are the individual elements comprehended nor is the remainder rounded into a whole.
As a matter of fact, Aristotle now goes on, in meteorology, to the consideration of the universal process of nature. But here we have reached his limits. Here, in the natural process, the simple determination as such—this system of progressive determination—ceases to hold good, and its whole interest is lost. For it is in the real process that these determinate conceptions always lose their signification again and become their opposite, and in it also this contingent succession is forced together and united. In determining time and motion, we certainly saw Aristotle himself uniting opposite determinations; but movement, in its true determination, must take space and time back into itself; it must represent itself as being the unity of these its real moments and in them; that is, as the realization of this ideal. But still more must the following moments, moisture, warmth, &c., themselves come back under the conception of process. But the sensuous manifestation here begins to obtain the upper hand; for the empirical has the nature of the isolated form, which is to fall out of relation. The empirical manifestation thus outstrips thought, which merely continues everywhere to stamp it as its own, but which has no longer power to permeate the manifestation, since it withdraws out of the sphere of the ideal, while it is still in the region of time, space and movement.
[3. The Philosophy of Mind.]
As regards the other side from the Philosophy of Nature, the Philosophy of Mind, we find that Aristotle has constituted in it also a separation into special sciences, in a series of works which I shall name. In the first place, his three books “On the Soul” deal partly with the abstract universal nature of the soul, though mainly in an antagonistic spirit; and even more, and in a fashion both profound and speculative, they deal with the soul’s essential nature—not with its Being, but with the determinate manner and potentiality of its energy; for this is to Aristotle the Being and essence of the soul. Thus there are several different treatises, viz.: On Sense-perception and the Sensible, On Memory and Recollection, On Sleeping and Waking, On Dreams, On Divination (μαντική) through Dreams, besides a treatise on Physiognomy; there is no empirical point of view or phenomenon, either in the natural or the spiritual world, that Aristotle has considered beneath his notice. With respect to the practical side, he in like manner devotes his attention to man in his capacity of householder, in a work on economics (οἰκονομικά); then he takes into his consideration the individual human being, in a moral treatise (ἠθικά), which is partly an inquiry into the highest good or the absolute end, and partly a dissertation on special virtues. The manner of treatment is almost invariably speculative, and sound understanding is displayed throughout. Finally, in his Politics, he gives a representation of the true constitution of a state and the different kinds of constitution, which he deals with from the empirical point of view; and in his Politics an account is given of the most important states, of which we are, however, told very little.
[a. Psychology.]
In Aristotle’s teaching on this subject we must not expect to find so-called metaphysics of the soul. For metaphysical handling such as this really pre-supposes the soul as a thing, and asks, for example, what sort of a thing it is, whether it is simple, and so on. Aristotle did not busy his concrete, speculative mind with abstract questions such as these, but, as already remarked, he deals rather with the manner of the soul’s activity; and though this appears in a general way as a series of progressive determinations which are not necessarily blended into a whole, each determination is yet apprehended in its own sphere with as much correctness as depth.