A STUDY IN THE HISTORY OF HELLENISM

CHAPTER V

THE PHILOSOPHICAL SYSTEM OF PLOTINUS

 

As idealists and their opponents alike recognize, one great stumbling-block of an idealist philosophy is language. This was seen by Plotinus, and by Berkeley, from the other side it is seen by the materialist and the dualist. Language was formed primarily to indicate the things of sense, and these have not the characters which idealism, whether ancient or modern, ascribes to reality. Ancient idealism refuses to call external things real in the full sense, because they are in flux. The reality is the fixed mental concept or its unchanging intelligible object. Modern idealism regards things as merely "phenomenal," because they appear to a consciousness, and beyond this appearance have no definable reality. Whether reality itself is fixed or changing, may by the modern idealist be left undetermined; but at any rate the groups of perceptions that make up the "objects" of daily experience and even of science are not, in his view, objects existing in themselves apart from mind, and known truly as such. Only by some relation to mind can reality be constituted. The way in which language opposes itself to ancient idealism is by its implication that existence really changes. To modern idealism it opposes itself by its tendency to treat external things as absolute objects with a real existence apart from that of all thinking subjects.

The two forms of developed idealism here regarded as typically ancient and modern are the earliest and the latest—that of Plato on the one side, that of post-Cartesian, and still more of post-Kantian, thinkers on the other. The idealism of Plotinus contains elements that bring it into relation with both. English readers know how Berkeley insists that, if we are to grasp his doctrine, we must attend to the meanings he desires to convey, and must not dwell on the mere form of expression. Let us see how Plato and Plotinus deal with the same difficulty.

Plato's treatment of it may be most readily studied in the Cratylus. Language, Socrates undertakes to show, has a certain natural conformity to things named. To those who named them, external things mostly presented themselves as in flux. Accordingly, words are full of devices by the makers of language for expressing gliding and flowing movements. With a little ingenuity and an occasional evasion, those who hold that the true nature of everything is to flow and not to be in any manner fixed, might exhibit the early legislators over human speech as in exact agreement with their philosophical opinions. Yet after all there are some words, though fewer, that appear at first sight to express stability. So that the primitive legislators were not, on the face of things, perfectly consistent. On the whole, however, words suggesting flux predominate. Similarly the early myth-makers, in their derivation of all things from Ocean and Tethys, seem to have noticed especially the fact of change in the world. The Heracliteans, therefore, have the advantage in the appeal to language and mythology. Still, their Eleatic opponents may be right philosophically. The makers of language and myth may have framed words and imagined the origin of things in accordance with what is apparent but not real. Real existence in itself may be stable. If this is so, then, to express philosophic thought accurately, it will be necessary to reform language. In the meantime, the proper method in all our inquiries and reasonings must be, to attend to things rather than words.

According to the Platonic doctrine, the "place of ideas" is the souls. In virtue of its peculiar relations to those stable and permanent existences known by intellect, the individual soul is itself permanent. It gives unity, motion and life to the fluent aggregate of material particles forming its temporary body. It disappears from one body and reappears in another, existing apart in the intervals between its mortal lives. Thus by Plato the opposition of soul and body is brought, as a subordinate relation, under the more general opposition of the stable ideas—the existence of which is not purely and simply in the soul, but is also in some way transcendent—and the flux of material existence. For Plotinus, this subordinate opposition has become the starting-point. He does not dismiss the earlier antithesis; but the main problem with him is not to find permanence somewhere as against absolute flux. He allows in the things of sense also a kind of permanence. His aim is first of all to prove that the soul has a real existence of its own, distinguished from body and corporeal modes of being. For in the meantime body as such—and no longer, as with the Heracliteans, a process of the whole—had been set up by the dominant schools as the absolute reality. By the Epicureans and Stoics, everything that can be spoken of at all was regarded as body, or a quality or relation of body, or else as having no being other than "nominal." The main point of attack for skepticism had been the position common to the naturalistic schools, that external things can be known by direct apprehension as they really are. Neither the Academical nor the Pyrrhonist skepticism, however, had taken the place of the ruling dogmatic system, which was that of the Stoics. Thus the doctrine that Plotinus had to meet was still essentially materialism, made by the skeptical attack less sure of itself, but not dethroned.

The method he adopts is to insist precisely on the paradoxical character of the soul's existence as contrasted with that of corporeal things. How specious is the view of his opponents he allows. Body can be seen and touched. It resists pressure and is spread out in space. Soul is invisible and intangible, and by its very definition unextended. Thus language has to be struggled with in the attempt to describe it; and in the end can only be made to express the nature of soul by constraining it to purposes for which most men never think of employing it. What is conclusive, however, as against the materialistic view, is that the soul cannot be described at all except by phrases which would be nonsensical if applied to body or its qualities, or to determinations of particular bodies. Once the conception of soul has been fixed as that of an incorporeal reality, body is seen to admit of a kind of explanation in terms of soul—from which it derives its "form" —whereas the essential nature of soul admitted of no explanation in terms of body.

Above soul and beneath body, as we shall see, Plotinus has other principles, derived from earlier metaphysics, by which he is able to construct a complete philosophy, and not merely what would be called in modern phrase a "rational psychology." His psychology, however, is the centre. Within the soul, he finds all the metaphysical principles in some way represented. In it are included the principles of unity, of pure intellect, of moving and vitalizing power, and, in some sense, of matter itself. Further, by what may be called his "empirical psychology," he prepared the starting-point for the distinctively modern "theory of knowledge." This he did, as Prof. Siebeck has shown, by the new precision he gave to the conception of consciousness. On this side he reaches forward to Descartes, as on the other side he looks back to Plato and Aristotle.

 

1. Psychology.

It is absurd, or rather impossible, says Plotinus at the opening of one of his earliest expositions, that life should be the product of an aggregation of bodies, or that things without understanding should generate mind. If, as some say, the soul is a permeating air with a certain habitude—and it cannot be air simply, for there are innumerable airs without life—then the habitude is either a mere name, and there is really nothing but the "breath," or it is a kind of being. In the latter case, it is a rational principle and of another nature than body. If the soul were matter, it could produce only the effects of the particular kind of matter that it is—giving things its own quality, hot or cold, and so forth—not all the opposite effects actually produced in the organism. The soul is not susceptible of quantitative increase or diminution, or of division. Thus it has not the characters of a thing possessing quantity. The unity in perception would be impossible if that which perceives consisted of parts spatially separated. It is impossible that the mental perception, for example, of a pain in the finger, should be transmitted from the "animal spirit" of the finger to the ruling part in the organism. For, in that case, there must either be accumulated an infinity of perceptions, or each intermediate part in succession must feel the pain only in itself, and not in the parts previously affected; and so also the ruling part when it becomes affected in its turn. That there can be no such physical transmission as is supposed of a mental perception, results from the very nature of material mass, which consists of parts each standing by itself: one part can have no knowledge of what is suffered by another part. Consequently we must assume a percipient which is everywhere identical with itself. Such a percipient must be another kind of being than body. That which thinks can still less be body than that which perceives. For even if it is not allowed that thought is the laying hold on intelligibles without the use of any bodily organ, yet there are certainly involved in it apprehensions of things without magnitude. Such are abstract conceptions, as for example those of the beautiful and the just. How then can that which is a magnitude think that which is not? Must we suppose it to think the indivisible with that in itself which is divisible? If it can think it at all, it must rather be with some indivisible part of itself. That which thinks, then, cannot be body. For the supposed thinking body has no function as an extended whole (and to be such is its nature as body), since it cannot as a whole come in contact with an object that is incorporeal.

The soul in relation to the body, according to Plotinus's own mode of statement, is "all in all and all in every parts." Thus it is in a sense divisible because it is in all the parts of a divisible body. Properly it is indivisible because it is all in the whole and all in each part of it. Its unity is unlike that of a body, which is one by spatial continuity, having different parts each of which is in a different place; and unlike that of a quality of body such as color, which can be wholly in many discontinuous bodies. In the case of a quality, that which is the same in all portions of body that possess it in common is an affection, and not an essence. Its identity is formal, and not numerical, as is the case with the soul.

In this general argumentation, it will be observed, Plotinus starts from the supposition that the body has a reality other than phenomenal. Allowing this, he is able to demonstrate against his opponents that a reality of a different kind from that of body must also be assumed. In his metaphysics he goes further, and reduces corporeal things in effect to phenomena; but in his psychology he continues to take a view nearer that of "common-sense." Thus he is confronted with the difficulties that have since become familiar about the "connection of body and mind," and the possibility of their interaction. He lays bare in a single saying the root of all such difficulties. How if, in talking of a "mixture" of a corporeal with an incorporeal nature, we should be trying to realize an impossibility, as if one should say that linear magnitude is mixed with whiteness? The solution for psychology is found in the theory that the soul itself remains "unmixed" in spite of its union with body; but that it causes the production of a "common" or "dual" or "composite" nature, which is the subject in perception. By the aid of this intermediary, the unity of the soul is reconciled—though not without perplexities in detail—with localization of the organic functions that subserve its activity.

The different parts of the animated body participate in the soul's powers in different ways. According as each organ of sense is fitted for one special function, a particular power of perception may be said to be there; the power of sight in the eyes, of hearing in the ears, of smell in the nostrils, of taste in the tongue, of touch everywhere. Since the primary organs of touch are the nerves, which have also the power of animal motion, and since the nerves take their origin from the brain, in the brain may be placed the starting-point of the actual exercise of all powers of perception and movement. Above perception is reason. This power has not properly a physical organ at all, and so is not really in the head; but it was assigned to the head by the older writers because it communicates directly with the psychical functions of which the brain is the central organ. For these last, as Plotinus remarks, have a certain community with reason. In perception there is a kind of judgment; and on reason together with the imagination derived from perception, impulse follows.

In making the brain central among the organs that are in special relation with mind, Plotinus of course adopts the Platonic as against the Aristotelian position, which made the heart central. At the same time, he incorporates what had since been discovered about the special functions of the nervous system, which were unknown to Aristotle as to Plato. The vegetative power of the soul he places in relation with the liver, because here is the origin of the veins and the blood in the veins, by means of which that power causes the nourishment of the body. Hence, as with Plato, appetite is assigned to this region. Spirited emotion, in accordance with the Platonic psychology, has its seat in the breast, where is the spring of lighter and purer blood.

Both perceptions and memories are "energies" or activities, not mere passive impressions received and stored up in the soul. Take first the case of the most distinct perception. In sight, when we wish to perceive anything clearly, we direct our vision in a straight line to the object. This outwardly directed activity would not be necessary if the object simply left its impression on the soul. 'Were this the whole process, we should see not the outward objects of vision, but images and shadows of them; so that what we see would be other than the things themselves. In hearing as in sight, perceptions are energies, not impressions nor yet passive states. The impression is an articulated stroke in the air, on which it is as if letters were written by that which makes the sound. The power of the soul as it were reads those impressions. In the case of taste and smell, the passive affections are one thing; the perceptions and judgments of them are another. Memory of things is produced by exercise of the soul, either generally or in relation to a special class of them. Children remember better because they have fewer things to attend to. Mere multitude of impressions retained, if memory were simply an affair of retaining impressions, would not cause them to be less remembered. Nor should we need to consider in order to remind ourselves; nor forget things and afterwards recall them to mind. The persistence of passive impressions in the soul, if real, would be a mark rather of weakness than of strength, for that which is most fixedly impressed is so by giving way. But where there is really weakness, as in the old, both memory and perception are worse.

The activity of perception, though itself mental, has direct physical conditions. That of memory has not. Memory itself belongs wholly to the soul, though it may take its start from what goes on in the composite being. What the soul directly preserves the memory of, is its own movements, not those of body: Pressure and reaction of bodies can furnish no explanation of a storing-up of mental "impressions", which are not magnitudes. That the body, through being in flux, is really a hindrance to memory, is illustrated by the fact that often additions to the store cause forgetfulness, whereas memory emerges when there is abstraction and purification. Something from the past that was retained but is latent may be recalled when other memories or the impressions of the moment are removed. Yet, though it is not the composite being but the soul itself that possesses memory, memories come to it not only from its spontaneous activity, but from its activity incited by that which takes place in consequence of its association with the body. There are memories of what has been done and suffered by the dual nature, though the memories themselves, as distinguished from that which incites them, are purely mental. Thus indirectly the physical organism has a bearing on memory as well as on perception. It follows, however, from the general view, that memory as well as reason belongs to the "separable" portion of the soul. Whether those who have attained to the perfection of virtue will, in the life of complete separation from the body, retain indefinitely their memories of the past, is another question. The discussion of it belongs rather to the ethics than to the pure psychology of Plotinus.

To specific questions about sense-perception, Plotinus devotes two short books, both of which are concerned primarily with vision. Discussing the transmission of light, he finds that, like all perception, seeing must take place through some kind of body. The affection of the medium, however, need not be identical with that of the sense-organ. A reed, for example, through which is transmitted the shock of a torpedo, is not affected like the hand that receives the shock. The air, he concludes, is no instrument in vision. If it were, we should be able to see without looking at the distant object; just as we are warmed by the heated air we are in contact with. In the case of heat too, Plotinus adds, we are warmed at the same time with the air, rather than by means of it. Solid bodies receive more of the heat than does the air intervening between them and the heated object. In pursuance of this argument, he remarks that even the transmission of sound is not wholly dependent on a stroke in an aerial medium. Tones vary according to the differences of the bodies from which the sound starts, and not simply according to the shock. Furthermore, sounds are transmitted within our bodies without the intermediation of air; as when bones are bent or sawn. The shock itself, whether in air or not, when it arrives at perception is the sound. Light Plotinus defines as an incorporeal energy of the luminous body directed outwards. Being an "energy," and not a mere quality, it is capable of overleaping an interval without becoming inherent in that which occupies the interval; as, in fact, it leaves no impress on the air through which it passes. It can exist in the interspace without a percipient, though a percipient, if present, would be affected by it.

For positive explanation here, Plotinus falls back on the idea, borrowed from the Stoics, of a "sympathy" binding together remote but like parts of the universe. The other book mentioned, which discusses the question why things seen at a distance appear small, is interesting from its points of contact with Berkeley. To solve the problem, Plotinus sets out in quest of something more directly psychological than the "visual angle." Is not one reason for differences of estimate, he asks, because our view of magnitude is in an "accidental" relation to color, which is what we primarily behold? To perceive how large any magnitude really is, we must be near it, so as to be able to go over its parts in succession. At a distance, the parts of the object do not permit accurate discernment of their relative coloring, since the colors arrive faint. Faintness in colors corresponds to smallness in magnitude; both have in common "the less". Thus the magnitude, following the color, is diminished proportionally. The nature of the affection, however, becomes plainer in things of varied colors. Confusion of colors, whether in near or distant objects, causes apparent diminution of size, because the parts do not offer differences by which they can be accurately distinguished and so measured. Magnitudes also of the same kind and of like colors are deceptive because the sight slips away; having, for precisely the same reason as in the case of confused colors, no hold on the parts. Again, distant objects look near at hand because there is loss of visible detail in the intervening scenery. Close as all this comes to Berkeley, at least in psychological method, the incidental remark comes still closer, that that to which we primarily refer visible magnitude appears to be touch. This occurs in a question about the "magnitude" of sound, to which reference is made by way of illustrating the analogy of great and small in different sense-perceptions.

Feeling, in the sense of pleasure and pain, according to Plotinus, belongs primarily to the animated body, in the parts of which it is localized. The perception of it, but not the feeling itself, belongs to the soul. Sometimes, however, in speaking of the feeling of pleasure or pain, we include along with it the accompanying perception. Corporal desires too have their origin from the common nature of the animated body. That this is their source is shown by the differences, in respect of desires, between different times of life, and between persons in health and disease. In his account of desire and aversion, Plotinus notes the coincidence between mental and bodily movements. The difference between the affection of the animated body on the one side and the soul's clear perception of it on the other, applies both to appetitive and to irascible emotion. Of these the second is not derived from the first, but both spring from a common root. That its origin cannot be entirely independent is shown by the fact that those who are less eager after bodily pleasures are less prone to anger and irrational passions. To explain the impulse to repel actively the cause of injury, we must suppose perception added to the mere resentment, which, as a passion, is primarily a boiling-up of the blood. The "trace of soul" on which this kind of emotion depends has its seat in the heart.

Error too arises from the common nature, by which right reason becomes weak, as the wisest counselor in an assembly may be overborne by the general clamour. The rational power, with Plotinus as with Aristotle, is in its own nature "unmixed"; but it has to manifest itself under conditions of time and in relation to the composite being. Further discussion of these points will in the main come better under the head of metaphysics than of psychology. A distinctively psychological theory, however, is the explicit transformation of the Platonic "reminiscence" into a doctrine of "innate ideas" potentially present. The term "memory," Plotinus observes, is improperly applied to the intellectual energizing of the soul in accordance with its innate principles. The reason why the older writers ascribed memory and reminiscence to the soul when it thus energizes, was apparently because it is then energizing in accordance with powers it always had (as it has now latent memories) but does not always bring into action, and especially cannot bring into action on its first arrival in the world. In this place for one Plotinus does not in the least fail to recognize that there has been scientific progress since the time of those whom he calls "the ancients."

The higher and the lower powers of the soul meet in the imaginative faculty, which is the psychical organ of memory and self-consciousness. By this view the dispersion is avoided that would result from assigning memory of desires to the desiring part of the soul, memories of perception to the perceiving part, and memories of thought to the thinking part. Thought is apprehended by the imagination as in a mirror; the notion at first indivisible and implicit being conveyed to it by an explicit discourse. For thought and the apprehension of thought are not the same the former can exist without the latter. That which thus apprehends thought apprehends perceptions also.

Here we come to the psychological conception of "consciousness," which Prof. Siebeck has traced through its formative stages to its practically adequate expression by Plotinus. By Plato and Aristotle, as he points out, such expressions are used as the "seeing of sight," and, at a higher degree of generality, the "perceiving of perception" and the "thinking of thought"; but they have no perfectly general term for the consciousness with which we follow any mental process whatever, as distinguished from the process itself. Approximations to such terms were made in the post-Aristotelian period by the Stoics and others, but it was Plotinus who first gained complete mastery of the idea. Sometimes he speaks of "common perception" in a generalized sense. His most usual expression is that of an "accompaniment" of its own mental activities by the soul. "Self-consciousness," in its distinctive meaning, is expressed by "accompanying oneself". With these terms are joined expressions for mental "synthesis" as a unitary activity of the soul in reference to its contents.

Important as the conception of consciousness became for modern thought, it is not for Plotinus the highest. Prof. Siebeck himself draws attention to one remarkable passage in which he points out that many of our best activities, both theoretical and practical, are unaccompanied at the time by consciousness of them; as for example reading, especially when we are reading intently; similarly, the performance of brave actions; so that there is a danger lest consciousness should make the activities it accompanies feebler. The rank assigned to introspective consciousness of mental activities is similar to that which is assigned to memory. It is above sense, but lower than pure intellect, which energizes with more perfection in its absence. The organ of introspection and of memory, as we have seen, is the same.

The highest mode of subjective life, next to the complete unification in which even thought disappears, is intellectual self-knowledge. Here the knower is identical with the known. On this too Plotinus is not without keen psychological observations, apart from the metaphysical developments next to be considered. The strong impression of a sense-perception, he remarks, cannot consist with the attainment of this intellectual unity. Whatever exaggerates feeling lowers the activity of thought. The perception of evils, for example, carries with it a more vehement shock, but less clear knowledge. We are more ourselves in health than in disease, but disease makes itself more felt, as being other than ourselves. The attitude of self-knowledge, Plotinus adds, is quite unlike that in which we know an object by external perception. Even the knower cannot place himself outside like a perceived object and gaze upon himself with the eyes of the body.

Within the mind as its very centre is the supreme unity beyond even self-knowledge. This is one with the metaphysical cause of all things, and must first be discussed as such, since the proof of its reality is primarily metaphysical. Its psychological relations will best be dealt with in the chapter on the mysticism of Plotinus.