§ 36.
1. In his physics Aristotle distinguishes between simple and composite bodies. He reckons as simple the four elements, Earth, Water, Air, Fire. Fire has a natural tendency upwards; the Earth naturally tends downwards, i.e. towards the centre of the world. Water and Air are intermediate between these extremes. The Earth occupies the lowest position; above it is Water; above Water, Air; and above Air, the sphere of Fire. In addition to these four simple elements, we have a fifth -- the Aether, extending from the heaven of the fixed stars to the moon, out of which the celestial spheres and heavenly bodies are formed. Composite or natural bodies are formed from the four first simple substances, and every composite body contains all four elements combining in different proportions. Aristotle rejects the World-Soul.
2. The Earth is at rest, and occupies the centre of the world. Beyond the sphere of Fire, which forms the extreme limit of the terrestrial region, the celestial spheres begin. The lowest of these is the sphere of the moon; then follow the spheres of the sun and of the planets; and lastly, forming the boundary of the celestial region, comes the sphere of the fixed stars. These celestial spheres revolve eternally round the Earth. The most rapid in its movement of revolution is the sphere of the fixed stars. As we descend the revolving movement becomes slower, and the lower spheres revolve in a direction contrary to the higher. The sphere of the fixed stars alone receives its motion immediately from the Prime Mover. The lower spheres have each its own mover, who, analogously to the Prime Mover, must be a pure entelechy, and therefore a nous, or Intelligence.
3. The celestial spheres are not subject to any process of generation or corruption, to any increase or diminution, or alteration. For the heavens are formed of the fifth element, and so do not contain any opposing elements which could render change possible; all change must therefore be excluded from them. It follows that what we style increase and diminution, alteration, generation and corruption, is wholly confined to the terrestrial or sublunary region. Nevertheless, the movements of the several parts of the universe affect one another. The motion of the lower celestial spheres depends upon that of the higher, and all generation, corruption, alteration, increase or diminution occurring in the sublunary region is dependent on the determining influence of the lowest of the celestial spheres, i.e. on its motion. The end of this common movement throughout the universe is to bring all things, each according to its position in the whole, to likeness with the Eternal Archetype. The heavens, by their eternal movement, most nearly attain to this perfection; it is attained in the lowest degree by sublunary things, the movements of which are imperfect and limited.
4. The sublunary region is the domain of what we call Nature. In all the changes which take place within it, Nature is working with a plan; it strives in every case after a determined end, and at all times aims at what is best. For this reason there is in its products a continuous gradation. Lowest in its scale are the inorganic, inanimate bodies; then follow organic beings with merely vegetable life (plants); next come organic beings with animal life (brutes); at the top of the scale stands man, superior to all other beings by his gift of reason, and by his reason sharing in the attributes of God. He is the ultimate end and purpose of Nature. The principle of life in organic beings Aristotle calls the Soul. The question naturally arises, What is the nature of the Soul in general, and what, especially, is the nature of the human Soul? Here we arrive at the Psychology of Aristotle.
5. In his treatise Peri psukês, Aristotle, according to his custom, first refutes the opinions of earlier philosophers regarding the nature of the Soul.
(a.) He refutes the opinion that the Soul is merely a Harmony between the parts of the body; his principal argument being that, in this case, the Soul could not be the principle of movement.
(b.) He refutes the opinion that the Soul is formed from one of the four natural elements, or by a combination of all four; his chief argument being that, in this case, the Soul would be capable only of those modifications which are characteristic of the elements, whereas the activity and modifications of the Soul are of a wholly different kind.
(c.) He combats Plato's view that self-movement constitutes the essential being of the Soul, and this chiefly on the ground that, in this case, the Soul would occupy space and would, therefore, be a corporeal being, and free to quit the body at pleasure.
6. So much being premised, Aristotle proceeds to give in positive terms his own notion of the Soul. He begins with the principle that every being of specifically determinate nature consists of Matter and Form. Accordingly, he holds that, in the case of the living being, the principle of life, or Soul, is the Form; the Body is the Matter. Form as we have seen, is the entelcehy -- the first, not the second, entelechy. The Soul, being the Form, is, therefore, tbe first entelechy of the Body. Not every body, however, can become the Matter in which a Soul is received, but only a physical body, and among physical bodies only such as are capable of sustaining life. To this class belong only organized bodies, for the unorganized, as such, exclude vitality. The Soul must therefore, be defined as the first enteleehy of a physical body, having life potentially, or briefly, the first entelechy of a physical organized body (entelecheia prôtê sômatos phusikou zoên echontos dunamei; or, entelecheia prôtê sômatos phusikou organikou. De Anim. II. c. 1.)
7. The Soul, being the Form or first entelechy of a physical organic body, it follows that it is also the end, as well as the moving principle of the latter. It is the end; for, as has been remarked, the Form, in the case of individual things, is always the end of their being, their ou heneka; it is the moving principle; for, as has been shown, the first entelechy is, in every case, the principle of energy or activity in the individual, and therefore, in the case of the living being, the vital energy is dependent on and arises from the first entelechy or Soul. The Soul, being on the one hand the end of the body, and on the other its moving principle, it becomes apparent that the body is the organ or instrument of the Soul; hence the thorough adaptation of parts observed in the bodily organism.
8. Having determined thus the general characteristics of the Soul as such, we must distinguish the various kinds of souls. There are as many different kinds of souls as there are different kinds of organized, living, animated beings. Lowest in this scale is the Soul of the plant. The functions of this Soul are purely vegetative. A degree higher is the brute Soul. This is the immediate principle of the animal functions in brutes. And, since it is the general law that the higher power virtually includes the lower, the brute Soul includes the virtue of the vegetative Soul, and is, therefore, the principle of the vegetative or organic functions of brute life. Highest in order comes the Soul of man, with which we have chiefly to concern ourselves.
9. Aristotle assigns five principal faculties to the human Soul: Vegetative Power (to threptikon), on which the maintenance of the corporeal organism depends; Appetitive Faculty (to orektikon), which is exerted in striving after what is good and agreeable, and in repelling what is disagreeable (dioxis kai phugê); the faculty of Sensuous Perception (to aisthêtikon), by which the objects perceptible by sense are represented in our cognition; the Locomotive Faculty (to kinêtikon), by which we are enabled to move the body and its members, and make use of them for external action; and lastly, the Reason (to dianoêtikon).
10. The four faculties first named belong to brutes as well as to man. Reason, on the other hand, is the characteristic which distinguishes man from the brutes. The Vegetative Power is not subject to the control of the Reason. The Appetitive Faculty is so connected with Reason, that its tendencies can and must be brought into accord with the requirements of Reason. This Appetitive Power is of two kinds -- the Concupiscible (to epithumêtikon) and the Irascible (to thumêtikon), according as it merely strives for what is good, or rises in opposition to the hindrances which stand between it and the attainment of the good it is seeking. External movement is dependent on the Locomotive Power of the Soul, though it is executed by the bodily organs in which the Soul has its seat. In man this faculty also is subject to the controlling influence of Reason.
11. With regard to the faculty of Sensuous Perception (to aisthêtikon), we must distinguish between simple aisthêsis (Perception by sense), Imagination (phantasia), and Memory, including Reminiscence (mnêmê kai anamnêsis).
(a.) In Sensuous Perception (aisthêsis) we must suppose the existence of a perceptible object, which exerts its influence on the Sense. In this process Sense is passive. Under the influence exerted by the object on Sense, there arises in a sensuous image (eidos aisthêton) of the object, which represents the sensible Form of the object, without the Matter; and through the Form thus presented the faculty of Sense has cognisance of the object. Each ~en~ has its proper (formal) object, but the same (concrete) thing may be perceived by several senses. The sense of Touch is the fundamental and most important sense; it is much more perfect in man than in brutes. Besides the External Senses, there is an Internal or Common Sense, underlying the former, and forming a common centre in which they all unite. Each of the several senses judges of the objects corresponding to itself; the Common Sense distinguishes between the objects of the several senses, and passes judgments regarding them.
(b.) By the faculty of Imagination man is enabled to retain and reproduce the eidê aisthêta of sensible objects without the immediate presence of these objects. The action of the Imagination is necessary for intellectual cognition, inasmuch as we must keep the object of intelligence before us under a sensuous image, and this sensuous image (phantasma) is presented by the Imagination.
(c.) The Memory (mnêmê) preserves the sensuous forms as the wax preserves the impression of the seal; and this is necessary to make possible the recollection of an object previously perceived. This recollection may be either involuntary, as in brutes; or it may be voluntary, i.e. the representations of things may be deliberately recalled to consciousness. The latter process is Reminiscence (anamnêsis), and is peculiar to man. The primary function of Memory is to preserve the sensible forms of things; but inasmuch as the objects of intelligence are presented under sensuous images, it happens that intellectual concepts also may be stored up in the memory.
12. To make possible the action of the Intellect (nous), a previous sensuous perception is necessary. The intellectual operation consists in this, that it divests the objects presented in sense of their material adjuncts, and apprehends the intelligible forms which attain actual existence under sensible conditions. As a result of this operation, there is generated in the Intellect an intellectual form (eidos noêton), which represents the intelligible being of the object, and by means of which the Intellect knows the object, and knows it, moreover, in its inner nature. It is evident that, in this process, the Intellect is not, like Sense, altogether passive, that we must distinguish in this connection its active from its passive (receptive) functions. We are thus led to distinguish between the Active Intellect and the Passive (intellectus agens and possibilis).
(a.) The Active Intellect (nous poiêtikos) renders actually intelligible the objects of sense, which, in themselves, are only potentially intelligible; and this it effects by a process of abstraction, which divests these objects of their material envelopment, and thus renders knowable the intelligible being of the object. It is a light rendering cognizable the intelligible being of things, in the same way that light in external nature renders sensible objects visible. The Active Intellect is pure energy without any potentiality; its activity is continuous.
(b.) The Passive Intellect (nous pathêtikos), on the other hand, receives the intelligible forms evolved by the abstractive process of the Active Intellect, and through these apprehends the intelligible being of the sensible objects. The Passive Intellect is thus, in a certain sense, moved to action by the Active Intellect, and holds towards the latter the relation of potency to activity. It is, so to speak, the locus of the intelligible process -- of the eidê noêta. And, inasmuch as it receives into itself the intelligible form of the object, it becomes, ideally, the thing which it apprehends, for it takes into itself the form of the object apprehended, and is put in action by it.
13. In this way the Intellect arrives at Concepts, and through these attains to the knowledge of First Principles, which are involved in the ultimate or highest concepts. The foundation is thus laid for the process of Inference, by which the mind, from knowledge possessed, advances to further knowledge. Inference is the function of the dianoia or Reason. The dianoia differs from the nous only in a relative sense. One and the same faculty is Intellect in one respect, Reason in another.
14. All the faculties of the Soul, other than the nous are essentially connected with the bodily organism, and their functions can be exercised only by means of the organs in which they are located. It is otherwise with the nous. This power does not act in combination with the bodily organism; it is a free faculty, and exercises activity without a corporeal organ. The reasons for this view are evident:
(a.) If the nous, like Sense, acted in combination with a bodily organ, the nous, like Sense, would be impaired and corrupted by too strong an impression of its proper object. The contrary, however, is found to be the case: the more intelligible the object- represented in its cognition, the more fully and more perfectly is it able to apprehend the object.
(b.) If the nous, as such, were immanent in the bodily organism, and could not act independently of the body, it would be touched by the affections of Sense, such as heat, cold -- an evident absurdity.
(c.) The functions which are exercised in combination with the body become impaired in proportion as the body grows weaker and more enfeebled. The nous, on the other hand, is neither altered nor enfeebled. If age and sickness sometimes exert a disturbing influence on the nous, this arises from the circumstance that the powers of sense on which it depends for its knowledge are yielding to progressive decay; in itself the nous is not affected by suffering, it is incapable of pain.
15. This is Aristotle's account of the psychical faculties in man. The results of his inquiry into the nature of the Soul's faculties enable him to determine with greater exactness the relations of the Soul to the Body. The following are the propositions which he lays down in this connection: --
(a.) The Soul (psuchê), regarded merely as the principle of vegetative and sensitive life, abstracting from the nous, is inseparable from the body. For, apart from the circumstance that it can exercise no function without the body, it is the entelechy of an organized body, and cannot, therefore, have actual existence apart from the body, of which it is the entelechy. It is separable from the body in our concept, but not in reality; it is not the body itself, but is sômatos ti, i.e., it belongs necessarily to the body. The nous, on the other hand, is separatus et immixtus; as it possesses an activity of its own distinct from the activity of the body, so does it possess actual being distinct from, and independent of, the body.
(b.) The Soul (psuchê), as the principle of vegetative and sensitive life, is produced by generation. In generation the male communicates the kinêtikon, the female gives the Materia. The body is thus derived from the female parent, the soul from the male, the element derived from the male parent being the entelechy of the element derived from the female. But the nous is not produced by generation, it comes to man from without, and unites itself with him (leipetai de, ton noun thurathen epeisienai, De Anim. II., c. 3.)
(c.) The Soul, as the principle of vegetative and sensitive life, is mortal; it comes into existence with the body, and it decays with the body. But the nous is incorruptible and immortal. Not having its origin with the body, and in the body, it cannot be dissolved with the body; it has actual being independent of the body.
16. These principles at once suggest a question as to the relations subsisting between the psuchê and the nous. The views of Aristotle on this point are not expressed with clearness, and in consequence two different interpretations of his teaching have been given by his later interpreters.
(a) One section -- the earlier interpreters of Aristotle, who in this matter are followed by the Arabian philosophers of the Middle Ages -- assume that Aristotle makes the nous something distinct from the individual soul, that he regards it as a principle distinct in being from the individual, a thing universal in nature, communicating itself to individual men, and thereby rendering them rational, without, however, losing its own essential unity. The reasons adduced in support of this interpretation of Aristotle are:
(1) Aristotle describes the nous as heteron genos psuchês, and teaches that it is not intrinsic to the soul, but comes to it from without, that it is in a certain sense implanted in the soul (egginesthai). (De Anim. II., c. 2. 11, I. c. 5. 5.)
(2) This is the only interpretation which gives the thurathen eisienai of Aristotle intelligible meaning.
(3.) Aristotle holds the lower faculty to be included in the higher, and hence will have the virtue of the vegetative soul to be included in the sensitive; but this principle he will not allow to have any application in the case of the nous and sensitive soul. (De Anim. II., c. 3, 9. 10.)
(b) Those who adopt this interpretation are further divided into two classes: the older interpreters, such as Alexander of Aphrodisias, assume that Aristotle, in this teaching, is dealing only with the nous poiêtikos, and that he makes the nous pathêtikos a faculty of the individual psuchê. They base this view on the fact that Aristotle asserts (De Anim. III., c. 6, 5), that the nous pathêtikos is corruptible (phthartos), whereas he asserts of the nous poiêtikos (De Anim. III., c. 6, 4), that it alone is chôristheis (separate), and, as such, is athanatos kai aidios (immortal and everlasting). Later interpreters, as for example, Averroes, separate both nous poiêtikos and nous pathêtikos from the individual soul, and consider both to form one universal being, transcending all individual souls.
(c) The Christian Scholastics of the Middle Ages, on the other, unanimously adopt the view that Aristotle understood the nous to be a faculty of the individual soul; and that when he describes it as seperatus et immixtus, he only means to signify that it is not essentially dependent on the corporeal organism. His statements regarding the corruptibility, generation, &c., of the soul, they held only to apply to the sensitive soul, as such, not to the rational human soul; to the latter they considered his doctrines of the nous to refer. In support of this interpretation they point out that Aristotle describes the intellect as a part of the soul, by which the soul thinks and becomes wise, that he asserts the soul reasons by means of the intellect -- a thing which would be impossible if the intellect were not an essential faculty of the soul.
17. We will not undertake to decide between these two views of Aristotle's teaching; they can each claim reasons in their favour. We may, however, point out, as somewhat remarkable, the circumstance that Aristotle, in his psychology, nowhere speaks of a personal immortality of the Soul; nay, the denial of such immortality appears to be involved in his assertion that the (active) Intellect, although immortal, preserves no memory of former events, i.e., individual thought and consciousness cannot be ascribed to it. (De Anim, III., c. 6, 5.) Even in his Ethics, where the doctrine of a personal immortality of the Soul would be of peculiar importance, no passage is to be found in which the doctrine is unequivocally laid down. On the contrary, we find it stated there (Eth. Nic. III., c. 9), that death is terrible, because it is the end of all, and because neither good nor evil awaits the dead beyond the grave. It is therefore, at best, highly doubtful whether Aristotle held the Soul to be personally immortal. On this point, again, he falls far behind Plato. If we hold that Aristotle does not teach a personal immortality, we must accept the view of his teaching taken by the older interpreters.
18. In conclusion, we must add a few words as to Aristotle's doctrine regarding the seat of the Soul. He is of opinion that the Soul is placed in the heart, for this, he thinks, is the centre of the body, and to this all the organs of sense converge. The Soul animates the body by means of the vital warmth, which has its source in the heart, and is maintained by the process of breathing. The more intense the animal heat in the living being, the more excellent is the Soul by which it is animated. Death is the extinction of this animal heat.