Front matter (continued 2)

The name "motion" has a wider sense for Aristotle than it has for ourselves. He includes under the one common name all the processes by which things come to be what they are or cease to be what they have been. Thus he distinguishes the following varieties of "motion": generation (the coming of an individual thing into being), with its opposite decay or corruption (the passing of a thing out of being), alteration (change of quality in a thing), augmentation and diminution (change in the magnitude of a thing), motion through space (of which latter he recognises two sub-species, rectilinear transference and rotation in a circular orbit about an axis). It is this last variety, motion through space, which is the most fundamental of all, since its occurrence is involved in that of any of the other types of process mentioned, though Aristotle does not hold the thorough-going mechanical view that the other processes are only apparent, and that, as we should put it, qualitative change is a mere disguise which mechanical motion wears for our senses.

The Eternity of Motion.--Certain very important consequences follow from the conception of efficient causation which we have been describing. Aristotle has no sympathy with the "evolutionist" views which had been favoured by some of his predecessors. According to his theory of organic generation, "it takes a man to beget a man "; where there is a baby, there must have been a father. Biological kinds representing real clefts in Nature, the process of the production of a young generation by an already adult generation must be thought of as without beginning and without end. There can be no natural "evolution" of animals of one species from individuals of a different kind. Nor does it occur to Aristotle to take into account the possibility of "Creationism," the sudden coming into being of a fully fledged first generation at a stroke. This possibility is excluded by the doctrine that the "matter" of a thing must exist beforehand as an indispensable condition of the production of that thing. Every baby, as we said, must have had a father, but that father must also have been a baby before he was a full-grown man. Hence the perpetuation of unchanging species must be without beginning and without end. And it is implied that all the various processes, within and without the organism, apart from which its life could not be kept up, must be equally without beginning and without end. The "cosmos," or orderly world of natural processes, is strictly "eternal"; "motion" is everlasting and continuous, or unbroken. Even the great Christian theologians who built upon Aristotle could not absolutely break with him on this point. St. Thomas, though obliged to admit that the world was actually created a few thousand years before his own time, maintains that this can only be known to be true from revelation, philosophically it is equably tenable that the world should have been "created from all eternity." And it is the general doctrine of scholasticism that the expression "creation" only denotes the absolute dependence of the world on God for its being. When we say "God created the world out of nothing," we mean that He did not make it out of pre-existing matter, that it depends for its being on Him only; the expression is purely negative in its import.

God.--With the doctrine of the eternity of the world and the processes which make up its life we come close to the culminating theory of Aristotelian First Philosophy, its doctrine of God, as the eternal, unchanging source of all change, movement, and process. All motion is a process within matter by which the forms latent in it are brought into actual manifestation. And the process only takes place in the presence of an adequate efficient cause or source of motion. Hence the eternity of natural processes involves the existence of one or more eternal sources of motion. For, if we do not admit the existence of an unoriginated and ever-present source or sources of motion, our only alternative is to hold that the world-process is due to a series of sources of motion existing successively. But such a view would leave the unity and unbroken continuity of the world-process unaccounted for. It would give us a succession of processes, temporally contiguous, not one unbroken process. Hence we argue from the continuity of motion to its dependence on a source or sources which are permanent and present throughout the whole everlasting world-process. And when we come to the question whether there is only one such ultimate source of movement for the whole universe, or several, Aristotle's answer is that the supreme "Unmoved Mover" is one. One is enough for the purpose, and the law of parcimony forbids us to assume the superfluous. This then is the Aristotelian conception of God and God's relation to the world. God is the one supreme unchanging being to whose presence the world responds with the whole process of cosmic development, the ultimate educer of the series of "forms" latent in the "matter" of the world into actual manifestation. Standing, as He does, outside the whole process which by His mere presence He initiates in Nature, He is not himself a composite of "form" and "matter," as the products of development are. He is a pure individual "form" or "actuality," with no history of gradual development behind it. Thus He is a purely immaterial being, indispensable to the world's existence but transcending it and standing outside it. How His presence inspires the world to move Aristotle tries to explain by the metaphor of appetition. Just as the good I desire and conceive, without itself "moving" "moves" my appetition, so God moves the universe by being its good. This directly brings about a uniform unbroken rotation of the whole universe round its axis (in fact, the alternation of day and night). And since this rotation is communicated from the outermost "sphere" of heaven to all the lesser "spheres" between it and the immovable centre, the effects of God's presence are felt universally. At the same time, we must note that though God is the supreme Mover of the Universe, He is not regarded by Aristotle as its Creator, even in the sense in which creation can be reconciled with the eternity of the world. For the effect of God's presence is simply to lead to the development of "form" in an already existing "matter." Without God there could be no "form" or order in things, not even as much as is implied in the differentiation of matter into the four "elements," yet "primary matter" is no less than God a precondition of all that happens.

It is characteristic of Aristotle that his God is as far from discharging the functions of a Providence as He is from being a Creator. His "activity" is not, as Plato had made it, that of the great "Shepherd of the sheep." As far as the world is concerned, God's only function is to be there to move its appetition. For the rest, the unbroken activity of this life is directed wholly inward. Aristotle expressly calls it an "activity of immobility." More precisely, he tells us, it is activity of thought, exercised unbrokenly and everlastingly upon the only object adequate to exercise God's contemplation, Himself. His life is one of everlasting self-contemplation or "thinking of thought itself." Like all unimpeded exercise of activity, it is attended by pleasure, and as the activity is continuous, so the pleasure of it is continuous too. At our best, when we give ourselves up to the pure contemplative activity of scientific thought or æsthetic appreciation, we enter for a while into this divine life and share the happiness of God. But that is a theme for our chapter on the Ethics.

It is a far cry from this conception of a God untroubled by care for a world to which He is only related as the object of its aspiration to the God who cares even for the fall of the sparrow and of whom it is written, Sic Deus dilexit mundum, but it was the standing task of the philosophical theologians of the Middle Ages to fuse the two conceptions. Plato's God, who, if not quite the Creator, is the "Father and Fashioner" of us all, and keeps providential watch over the world He has fashioned, would have lent Himself better to their purposes, but Plato was held by the mediæval church to have denied the resurrection of the body. The combination of Aristotle's Theism with the Theism of early Christianity was effected by exquisitely subtle logical devices, but even in St. Thomas one cannot help seeing the seams.

Nor can one help seeing in Aristotle's own doctrine the usual want of coherence between an initial anti-Platonic bias and a final reversion to the very Platonic positions Aristotle is fond of impugning. We are told at the outset that the Platonic "separate forms" are empty names, and that the real individual thing is always a composite of matter and a form which only exists "in matter." We find in the end that the source of the whole process by which "matter" becomes imbued with "form" is a being which is "pure" form and stands outside the whole development which its presence sets up. And the issue of Aristotle's warning against "poetic metaphors" is the doctrine that God moves the world by being "the object of the world's desire."

CHAPTER IV

PHYSICS

There is no part of Aristotle's system which has been more carefully thought out than his Physics; at the same time it is almost wholly on account of his physical doctrines that his long ascendancy over thought is so much to be regretted. Aristotle's qualifications as a man of science have been much overrated. In one department, that of descriptive natural history, he shows himself a master of minute and careful observation who could obtain unqualified praise from so great a naturalist as Darwin. But in Astronomy and Physics proper his inferiority in mathematical thinking and his dislike for mechanical ways of explaining facts put him at a great disadvantage, as compared with Plato and Plato's Pythagorean friends. Thus his authority was for centuries one of the chief influences which prevented the development of Astronomy on right lines. Plato had himself both taught the mobility of the earth and denied correctly that the earth is at the centre of the universe, and the "Copernican" hypothesis in Astronomy probably originated in the Academy. Aristotle, however, insists on the central position of the earth, and violently attacks Plato for believing in its motion. It is equally serious that he insists on treating the so-called "four elements" as ultimately unanalysable forms of matter, though Plato had not only observed that so far from being the ABC (stoicheia or elementa, literally, letters of the alphabet) of Nature they do not deserve to be called even "syllables," but had also definitely put forward the view that it is the geometrical structure of the "corpuscles" of body upon which sensible qualities depend. It is on this doctrine, of course, that all mathematical physics rests. Aristotle reverts to the older theory that the differences between one "element" and another are qualitative differences of a sensible kind. Even in the biological sciences Aristotle shows an unfortunate proneness to disregard established fact when it conflicts with the theories for which he has a personal liking. Thus, though the importance of the brain as the central organ of the sensori-motor system had been discovered in the late sixth or early fifth century by the physician Alemacon of Crotona, and taught by the great Hippocrates in the fifth and by Plato in the fourth century, Aristotle's prejudices in favour of the doctrines of a different school of biologists led him to revert to the view that it is the heart which is the centre of what we now call the "nervous system." It is mainly on account of these reactionary scientific views that he was attacked in the early seventeenth century by writers like our own Francis Bacon, who found in veneration for Aristotle one of the chief hindrances to the free development of natural science. The same complaints had been made long before by critics belonging to the Platonic Academy. It is a Platonist of the time of Marcus Aurelius who sums up a vigorous attack on the Aristotelian astronomy by the remark that Aristotle never understood that the true task of the physicist is not to prescribe laws to Nature, but to learn from observation of the facts what the laws followed by Nature are.

In determining the scope of Physics, we have to begin by considering what is the special characteristic of things produced by Nature as contrasted with those produced by "art." The obvious distinction, intimated by the very etymology of the word "Nature" (physis, connected with phyesthai, to grow, to be born, as natura is with nasci), is that "what is by Nature" is born and grows, whereas what is as a result of artifice is made. The "natural" may thus be said to consist of living bodies and of their constituent parts. Hence inorganic matter also is included in "Nature," on the ground that living tissue can be analysed back into compounds of the "elements." Now things which are alive and grow are distinguished from things which are made by "a source of motion and quiescence within themselves"; all of them exhibit motions, changes of quality, processes of growth and decline which are initiated from within. Hence Nature may be defined as the totality of things which have a source of motion internal to themselves and of the constituent parts of such things. Nature then comprises all beings capable of spontaneous change. Whatever either does not change at all, or only changes in consequence of external influences, is excluded from Nature.

Thus the fundamental fact everywhere present in Nature is "change," "process," "motion." Since motion in the literal sense of change of position is involved as a condition of every such process, and such motion requires space through which to move and time to move in, the doctrine of space and time will also form part of Physics. Hence a great part of Aristotle's special lectures on Physics is occupied with discussion of the nature of space and time, and of the continuity which we must ascribe to them if the "continuous motion" on which the unbroken life of the universe depends is to be real Aristotle knows nothing of the modern questions whether space and time are "real" or only "phenomenal," whether they are "objective" or "subjective." Just as he simply assumes that bodies are things that really exist, whether we happen to perceive them or not, so he assumes that the space and time in which they move are real features of a world that does not depend for its existence on our perceiving it.

His treatment of space is singularly naïf. He conceives it as a sort of vessel, into which you can pour different liquids. Just as the same pot may hold first wine and then water, so, if you can say, "there was water here, but now there is air here," this implies the existence of a receptacle which once held the water, but now holds the air. Hence a jug or pot may be called a "place that can be carried about," and space or place may be called "an immovable vessel." Hence the "place" of a thing may be defined as the boundary, or inner surface, of the body which immediately surrounds the thing. It follows from this that there can be no empty space. In the last resort, "absolute space" is the actual surface of the outermost "heaven" which contains everything else in itself but is not contained in any remoter body. Thus all things whatever are "in" this "heaven." But it is not itself "in" anything else. In accord with the standing Greek identification of determinate character with limitation, Aristotle holds that this outermost heaven must be at a limited distance from us. Actual space is thus finite in the sense that the volume of the universe could be expressed as a finite number of cubic miles or yards, though, since it must be "continuous," it is infinitely divisible. However often you subdivide a length, an area, or a volume, you will always be dividing it into lesser lengths, &c., which can once more be divided. You will never by division come to "points," i.e. mere positions without magnitude of divisibility.

The treatment of time is more thoughtful. Time is inseparably connected with movement or change. We only perceive that time has elapsed when we perceive that change has occurred. But time is not the same as change. For change is of different and incommensurate kinds, change of place, change of colour, &c.; but to take up time is common to all these forms of process. And time is not the same as motion. For there are different rates of speed, but the very fact that we can compare these different velocities implies that there are not different velocities of time. Time then is that in terms of which we measure motion, "the number of motion in respect of before and after," i.e. it is that by which we estimate the duration of processes. Thus e.g. when we speak of two minutes, two days, two months as required for a certain process to be completed, we are counting something. This something is time. It does not seem to occur to Aristotle that this definition implies that there are indivisible bits of time, though he quite correctly states the incompatible proposition that time is "made up of successive nows," i.e. moments which have no duration at all, and can no more be counted than the points on a straight line. He recognises of course that the "continuity" of motion implies that of time as well as of space. Since, however, "continuity" in his language means the same thing as indefinite divisibility, it ought not to be possible for him to regard time as "made up of nows"; time, like linear extension, ought for him to be a "length of" something.

The Continuous Motion and the "Spheres."--The continuous world-process depends upon a continuous movement set up in the universe as a whole by the presence of an everlasting and unchangeable "First Mover," God. From the self-sameness of God, it follows that this most universal of movements must be absolutely uniform. Of what precise kind can such a movement be? As the source of the movement is one, and the object moved is also one--viz. the compass of the "heaven," the movement of the primum mobile or "first moved"--the object immediately stimulated to motion by God's presence to it, must be mechanically simple. Now Aristotle, mistakenly, held that there are two forms of movement which are simple and unanalysable, motion of translation along a straight line, and motion of rotation round an axis. He is at pains to argue that rectilinear motion, which we easily discover to be that characteristic of bodies near the earth's surface when left to themselves, cannot be the kind of movement which belongs to the "heaven" as a whole. For continuous rectilinear movement in the same direction could not go on for ever on his assumption that there is no space outside the "heaven," which is itself at a finite distance from us. And motion to and fro would not be unbroken, since Aristotle argues that every time a moving body reached the end of its path, and the sense of its movement was reversed, it would be for two consecutive moments in the same place, and therefore at rest. Reversal of sense would imply a discontinuity. Hence he decides that the primary unbroken movement must be the rotation of the "first moved"--that is, the heaven containing the fixed stars--round its axis. This is the only movement which could go on for ever at a uniform rate and in the same sense. Starting with the conviction that the earth is at rest in the centre of the universe, he inevitably accounts for the alternation of day and night as the effect of such a revolution of the whole universe round an axis passing through the centre of the earth. The universe is thus thought of as bounded by a spherical surface, on the concave side of which are the fixed stars, which are therefore one and all at the same distance from us. This sphere, under the immediate influence of God, revolves on its axis once in twenty-four hours, and this period of revolution is absolutely uniform. Next the apparently irregular paths of the "planets" known to Aristotle (i.e. the moon, Mercury, Venus, the sun, Mars, Jupiter, Saturn) are resolved into combinations of similar uniform rotations, each planet having as many "spheres" assigned to it as are requisite for the analysis of its apparent path into perfectly circular elementary motions. Altogether Aristotle holds that fifty-four such rotating spheres are required over and above the "first moved" itself, whose rotation is, of course, communicated to all the lesser "spheres" included within it. As in the case of the "first moved," the uniform unceasing rotation of each "sphere" is explained by the influence on it of an unchanging immaterial "form," which is to its own "sphere" what God is to the universe as a whole. In the Aristotelianism of the mediæval church these pure forms or intelligences which originate the movements of the various planetary spheres are naturally identified with angels. It is e.g. to the angelic intelligences which "move" the heaven of Venus, which comes third in order counting outward from the earth, that Dante addresses his famous Canzone, Voi ch' intendendo il terzo del movete. The mediæval astronomy, however, differs in two important respects from that of Aristotle himself. (1) The number of "spheres" is different. Increasing knowledge of the complexity of the paths of the planets showed that if their paths are to be analysed into combinations of circular motions, fifty-four such rotations must be an altogether inadequate number. Aristotle's method of analysis of the heavenly movements was therefore combined with either or both of two others originated by pure astronomers who sat loose to metaphysics. One of these methods was to account for a planet's path by the introduction of epicycles. The planet was thought of not as fixed at a given point on its principal sphere, but as situated on the circumference of a lesser sphere which has its centre at a fixed point of the principal sphere and rotates around an axis passing through this centre. If need were, this type of hypothesis could be further complicated by imagining any number of such epicycles within epicycles. The other method was the employment of "eccentrics," i.e. circular movements which are described not about the common centre of the earth and the universe, but about some point in its neighbourhood. By combinations of epicycles and eccentrics the mediæval astronomers contrived to reduce the number of principal spheres to one for each planet, the arrangement we find in Dante. (2) Also real or supposed astronomical perturbations unknown to Aristotle led some mediæval theorists to follow the scheme devised by Alphonso the Wise of Castille, in which further spheres are inserted between that of Saturn, the outermost planet, and the "first moved." In Dante, we have, excluding the "empyrean" or immovable heaven where God and the blessed are, nine "spheres," one for each of the planets, one for the fixed stars, and one for the "first moved," which is now distinguished from the heaven of the stars. In Milton, who adopts the "Alphonsine" scheme, we have further a sphere called the "second movable" or "crystalline" introduced between the heaven of the fixed stars and the "first moved," to account for the imaginary phenomenon of "trepidation."[#] In reading Dante, Shakespeare, and Milton, we have always to remember that none of these reproduces the Aristotelian doctrine of the "spheres" accurately; their astronomy is an amalgam of Aristotle, Ptolemy, and Hipparchus.

[#] Paradise Lost, iii. 481.

"They pass the planets seven, and pass the fixed, And that crystalline sphere whose balance weighs The trepidation talked, and that first moved."

So far, the doctrine of the fifty-five "spheres" might be no more than a legitimate mathematical fiction, a convenient device for analysing the complicated apparent movements of the heavenly bodies into circular components. This was originally the part played by "spheres" in ancient astronomical theory, and it is worth while to be quite clear about the fact, as there is a mistaken impression widely current to-day that Aristotle's astronomy is typical of Greek views in general. The truth is that it is peculiar to himself. The origin of the theory was Academic. Plato proposed to the Academy as a subject of inquiry, to devise such a mathematical analysis of astronomical motions as will best "save the appearances," i.e. will most simply account for the apparent paths of the planets. The analysis of these paths into resultants of several rotations was offered as a solution by the astronomer Eudoxus of Cnidus. So far, the "spheres," then, were a mere mathematical hypothesis. What Aristotle did, and it is perhaps the most retrograde step ever taken in the history of a science, was to convert the mathematical hypothesis into physical fact. The "spheres" become with him real bodies, and as none of the bodies we are familiar with exhibit any tendency to rotate in circles when left to themselves, Aristotle was forced to introduce into Physics the disastrous theory, which it was a great part of Galileo's life-work to destroy, that the stuff of which the spheres are made is a "fifth body," different from the "elements" of which the bodies among which we live are made. Hence he makes an absolute distinction between two kinds of matter, "celestial matter," the "fifth body," and "terrestrial" or "elementary" matter. The fundamental difference is that "terrestrial" or "elementary" matter, left to itself, follows a rectilinear path, "celestial" matter rotates, but it is further inferred from the supposed absolute uniformity of the celestial movements that "celestial matter" is simple, uncompounded, incapable of change, and consequently that no new state of things can ever arise in the heavens. The spheres and planets have always been and will always be exactly as they are at the present moment. Mutability is confined to the region of "terrestrial" or "elementary" matter, which only extends as far as the orbit of the moon, the "lowest of the celestial bodies," because it is only "terrestrial" things which are, as we should say, chemical compounds. This is the doctrine which Galileo has in mind when he dwells on such newly-discovered astronomical facts as the existence of sun-spots and variable stars, and the signs of irregularity presented by the moon's surface. The distinction is peculiar to Aristotle. No one before him had ever thought of supposing the heavenly bodies to be made of any materials other than those of which "bodies terrestrial" are made. In the Academic attack on Aristotle's science of which we have already spoken the two points singled out for reprobation are (1) his rejection of the principle that all moving bodies, left to themselves, follow a rectilinear path, and (2) his denial that the heavenly bodies are made of the same "elements" as everything else. (It may just be mentioned in passing that our word quintessence gets its sense from the supposed special "nobility" of the incorruptible "fifth body.")

Terrestrial Bodies.--As we have seen already, Aristotle was out of sympathy with the tendency to regard the sensible differences between bodies as consequences of more ultimate differences in the geometrical structure of their particles. Hence his whole attitude towards the problems of that branch of natural science which we call physics is quite unlike any view to which we are accustomed. He reverts from the mathematical lines of thought current in Plato's Academy to the type of view more natural to the "plain man," and, like the earliest sixth-century men of science, regards the qualitative differences which our senses apprehend as fundamental. Among these, particular stress is laid on the difference in sensible temperature (the hot--the cold), in saturation (the dry--the moist), and in density (the dense--the rare). If we consider the first two of these oppositions, we can make four binary combinations of the elementary "opposite" characters, viz. hot and dry, hot and moist, cold and moist, cold and dry. These combinations are regarded as corresponding respectively to the sensible characteristics of the four bodies which Empedocles, the father of Greek chemistry, had treated as the ultimate components of everything. Fire is hot and dry, air hot and moist, water moist and cold, earth cold and dry. This reflection shows us why Aristotle held that the most rudimentary form in which "matter" ever actually exists is that of one of these "elements." Each of them has one quality in common with another, and it is in virtue of this that a portion of one element can be assimilated by and transmuted into another, a process which seems to the untutored eye to be constantly recurring in Nature. We also observe that the order in which the "elements" appear, when so arranged as to form a series in which each term has one quality in common with each of its neighbours, is also that of their increasing density. This would help to make the conception of their transmutability all the more natural, as it suggests that the process may be effected by steady condensation. We must remember carefully that for Aristotle, who denies the possibility of a vacuum, as for the mediæval alchemists, condensation does not mean a mere diminution of the distances between corpuscles which remain unchanged in character, but is a process of real qualitative change in the body which undergoes it. Incidentally we may remark that all changes of quality are regarded by Aristotle as stages in a continuous "movement" from one extreme of a scale to another. For example, colours, with him as with Goethe, form a series of which the "opposites" white and black are the end-points. Every other colour is a combination of white and black according to a definite proportion.

The Aristotelian doctrine of weight was one of the chief obstacles which seventeenth-century science had to contend with in establishing correct notions in dynamics. It is a curious feature of Greek science before Aristotle that, though the facts connected with gravity were well known, no one introduced the notion of weight to account for them. The difference between heavy bodies and light bodies had been previously treated as secondary for science. Plato's treatment of the matter is typical of the best fourth-century science. We must not try to explain why the heavier bodies tend to move towards the earth's surface by saying that they have a "downward" motion; their motion is not downward but "towards the centre" (the earth, though not fixed at the centre of the universe, being nearer to it than the rest of the solar and sidereal system). Plato then explains the tendency in virtue of which the heavier bodies move towards the "centre" as an attraction of like for like. The universal tendency is for smaller masses of "earth," "water," "air," "fire" to be attracted towards the great aggregations of the same materials. This is far from being a satisfactory theory in the light of facts which were not yet known to Plato, but it is on the right lines. It starts from the conception of the facts of gravity as due to an "attractive force" of some kind, and it has the great merit of bringing the "sinking" of stones and the "rising" of vapours under the same explanation.

Aristotle, though retaining the central idea that a body tends to move towards the region where the great cosmic mass of the same kind is congregated, introduced the entirely incompatible notion of an absolute distinction of "up" and "down." He identified the centre of the universe with that of the earth, and looked on motion to this centre as "downward." This led him to make a distinction between "heavy" bodies, which naturally tend to move "down," and "light" bodies, which tend to move "up" away from the centre. The doctrine works out thus. The heaviest elements tend to be massed together nearest the centre, the lightest to be furthest from it. Each element thus has its "proper place," that of water being immediately above earth, that of air next, and that of fire furthest from the centre, and nearest to the regions occupied by "celestial matter." (Readers of Dante will recollect the ascent from the Earthly Paradise through the "sphere of fire" with which the Paradiso opens.)

In its own "proper region" no body is heavy or light; as we should say any fluid loses its weight when immersed in itself. When a portion of an element is out of its own region and surrounded by the great cosmic aggregate of another element, either of two cases may occur. The body which is "out of its element" may be below its proper place, in which case it is "light" and tends to move perpendicularly upwards to its place, or it may be above its proper place, and then it is "heavy" and tends to move perpendicularly "down" until it reaches its place. It was this supposed real distinction between motion "up" and motion "down" which made it so hard for the contemporaries of Galileo to understand that an inflated bladder rises for the same reason that a stone sinks.

Biology.--Of Aristotle's biology reasons of space forbid us to say much here. But a remark or two may be made about his theory of reproduction, since it is constantly referred to in much modern literature and has also played its part in theology. An interesting point is the distinction between "perfect" and "imperfect" animals. "Perfect" animals are those which can only be reproduced sexually. Aristotle held, however, that there are some creatures, even among vertebrates, which may be produced by the vivifying effect of solar heat on decomposing matter, without any parents at all. Thus malobservation of the facts of putrefaction led to the belief that flies and worms are engendered by heat from decaying bodies, and it was even thought that frogs and mice are produced in the same way from river-slime. In this process, the so-called "aequivocal generation," solar heat was conceived as the operative efficient cause which leads to the realisation of an organic "form" in the decaying matter.

In sexual reproduction Aristotle regards the male parent as the agent or efficient cause which contributes the element of form and organisation to the offspring. The female parent supplies only the raw material of the new creature, but she supplies the whole of this. No material is supplied by the male parent to the body of the offspring, a theory which St. Thomas found useful in defending the dogma of the Virgin Birth.

Psychology.--Since the mind grows and develops, it comes under the class of things which have a "source of motion internal to themselves," and psychology is therefore, for Aristotle, a branch of Physics. To understand his treatment of psychological questions we need bear two things in mind. (1) Psyche or "soul" means in Greek more than "consciousness" does to us. Consciousness is a relatively late and highly developed manifestation of the principle which the Greeks call "soul." That principle shows itself not merely in consciousness but in the whole process of nutrition and growth and the adaptation of motor response to an external situation. Thus consciousness is a more secondary feature of the "soul" in Greek philosophy than in most modern thought, which has never ceased to be affected by Descartes' selection of "thought" as the special characteristic of psychical life. In common language the word psyche is constantly used where we should say "life" rather than "soul," and in Greek philosophy a work "on the Psyche" means what we should call one on "the principle of life."

(2) It is a consequence of this way of thinking of the "soul" that the process of bodily and mental development is regarded by Aristotle as one single continuous process. The growth of a man's intellect and character by which he becomes a thinker and a citizen is a continuation of the process by which his body is conceived and born and passes into physical manhood. This comes out in the words of the definition of the soul. "The soul is the first entelechy (or actual realisation) of a natural organic body." What this means is that the soul stands to the living body as all form realised in matter does to the matter of which it is the form, or that the soul is the "form" of the body. What the "organic body" is to the embryo out of which it has grown, that soul is to the body itself. As the embryo grows into the actual living body, so the living body grows into a body exhibiting the actual directing presence of mind. Aristotle illustrates the relation by the remark that if the whole body was one vast eye, seeing would be its soul. As the eye is a tool for seeing with, but a living tool which is part of ourselves, so the body is a like tool or instrument for living with. Hence we may say of the soul that it is the "end" of the body, the activity to which the body is instrumental, as seeing is the "end" to which the eye is instrumental. But we must note that the soul is called only the "first" or initial "entelechy" of the body. The reason is that the mere presence of the soul does not guarantee the full living of the life to which our body is but the instrument. If we are to live in the fullest sense of the word, we must not merely "have" a soul; we "have" it even in sleep, in ignorance, in folly. The soul itself needs further to be educated and trained in intelligence and character, and to exercise its intelligence and character efficiently on the problems of thought and life. The mere "presence" of soul is only a first step in the progress towards fullness of life. This is why Aristotle calls the soul the first entelechy of the living body. The full and final entelechy is the life of intelligence and character actively functioning.

From this conception of the soul's relation to the body we see that Aristotle's "doctrine of body and mind" does not readily fall into line with any of the typical theories of our time. He neither thinks of the soul as a thing acting on the body and acted on by it, nor yet as a series of "states of mind" concomitant with certain "states of body." From his point of view to ask whether soul and body interact, or whether they exhibit "parallelism," would be much the same thing as to ask whether life interacts with the body, or whether there is a "parallelism" between vital processes and bodily processes. We must not ask at all how the body and soul are united. They are one thing, as the matter and the form of a copper globe are one. Thus they are in actual fact inseparable. The soul is the soul of its body and the body the body of its soul. We can only distinguish them by logical analysis, as we can distinguish the copper from the sphericity in the copper globe.

Grades of Psychical Life.--If we consider the order of development, we find that some vital activities make their appearance earlier than others, and that it is a universal law that the more highly developed activities always have the less highly developed as their basis and precondition, though the less highly developed may exist apart from the more highly developed. So we may arrange vital activities in general in an ontogenetic order, the order in which they make their appearance in the individual's development. Aristotle reckons three such stages, the "nutritive," the "sensitive," and the "intelligent." The lowest form in which life shows itself at all, the level of minimum distinction between the living and the lifeless, is the power to take in nutriment, assimilate it, and grow. In vegetables the development is arrested at this point. With the animals we reach the next highest level, that of "sensitive" life. For all animals have at least the sense of touch. Thus they all show sense-perception, and it is a consequence of this that they exhibit "appetition," the simplest form of conation, and the rudiments of feeling and "temper." For what has sensations can also feel pleasure and pain, and what can feel pleasure and pain can desire, since desire is only appetition of what is pleasant. Thus in the animals we have the beginnings of cognition, conation, and affective and emotional life in general. And Aristotle adds that locomotion makes its appearance at this level; animals do not, like plants, have to trust to their supply of nutriment coming to them; they can go to it.

The third level, that of "intelligence," i.e. the power to compare, calculate, and reflect, and to order one's life by conscious rule, is exhibited by man. What distinguishes life at this level from mere "sensitive" life is, on the intellectual side, the ability to cognise universal truths, on the conative, the power to live by rule instead of being swayed by momentary "appetition." The former gives us the possibility of science, the latter of moral excellence.[#]

[#] Cf. Dante's "Fatti non foste a viver como bruti,

Ma per seguir virtute e conosoenza."

Sensation.--Life manifests itself at the animal level on the cognitive side as sense-perception, on the conative as appetition or desire, on the affective as feeling of pleasure or pain, and in such simple emotional moods as "temper," resentment, longing. Aristotle gives sensation a logical priority over the conative and emotional expression of "animal" life. To experience appetition or anger or desire you must have an object which you crave for or desire or are angry with, and it is only when you have reached the level of presentations through the senses that you can be said to have an object. Appetition or "temper" is as real a fact as perception, but you cannot crave for or feel angry with a thing you do not apprehend.

Aristotle's definition of sense perception is that it is a "capacity for discerning" or distinguishing between "the sensible qualities of things." His conception of the process by which the discernment or distinguishing is effected is not altogether happy. In sense-perception the soul "takes into itself the form of the thing perceived without its matter, as sealing-wax receives the shape of an iron seal-ring without the iron." To understand this, we have to remember that for Aristotle the sensible qualities of the external world, colour, tones, tastes, and the rest, are not effects of mechanical stimulation of our sense-organs, but real qualities of bodies. The hardness of iron, the redness of a piece of red wax are all primarily "in" the iron or the wax. They are "forms," or determinations by definite law, of the "matter" of the iron or the wax. This will become clearer if we consider a definite example, the red colour of the wax. In the wax the red colour is a definite combination of the colour-opposites white and black according to a fixed ratio. Now Aristotle's view of the process of sense-perception is that when I become aware of the red colour the same proportion of white to black which makes the wax red is reproduced in my organ of vision; my eye, while I am seeing the red, "assimilated" to the wax, is itself for the time actually "reddened." But it does not become wax because the red thing I am looking at is a piece of red wax. The eye remains a thing composed of living tissues. This is what is meant by saying that in seeing the colours of things the eye receives "forms" without the "matter" of the things in which those forms are exhibited. Thus the process of sense-perception is one in which the organ of sense is temporarily assimilated to the thing apprehended in respect of the particular quality cognised by that organ, but in respect of no other. According to Aristotle this process of "assimilation" always requires the presence of a "medium." If an object is in immediate contact with the eye we cannot see its colour; if it is too near the ear, we do not discern the note it gives out. Even in the case of touch and taste there is no immediate contact between the object perceived and the true organ of perception. For in touch the "flesh" is not the organ of apprehension but an integument surrounding it and capable of acting as an intermediary between it and things. Thus perception is always accomplished by a "motion" set up in the "medium" by the external object, and by the medium in our sense-organs. Aristotle thus contrives to bring correct apprehension by sense of the qualities of things under the formula of the "right mean" or "right proportion," which is better known from the use made of it in the philosopher's theory of conduct. The colour of a surface, the pitch of the note given out by a vibrating string, &c., depend on, and vary with, certain forms or ratios "in" the surface or the vibrating string; our correct apprehension of the qualities depends on the reproduction of the same ratios in our sense-organs, the establishment of the "right proportion" in us. That this "right proportion" may be reproduced in our own sense-organs it is necessary (1) that the medium should have none of the sensible qualities for the apprehension whereof it serves as medium, e.g. the medium in colour-perception must be colourless. If it had a colour of its own, the "motion" set up by the coloured bodies we apprehend would not be transmitted undistorted to our organs; we should see everything through a coloured haze. It is necessary for the same reason (2) that the percipient organ itself, when in a state of quiescence, should possess none of the qualities which can be induced in it by stimulation. The upshot of the whole theory is that the sense-organ is "potentially" what the sense-quality it apprehends is actually. Actual perceiving is just that special transition from the potential to the actual which results in making the organ for the time being actually of the same quality as the object.

The Common Sensibles and the Common Sense-organ.--Every sense has a range of qualities connected with it as its special objects. Colours can only be perceived by the eye, sounds by the ear, and so forth. But there are certain characters of perceived things which we appear to apprehend by more than one sense. Thus we seem to perceive size and shape either by touch or by sight, and number by hearing as well, since we can count e.g. the strokes of an unseen bell. Hence Aristotle distinguishes between the "special sensible qualities" such as colour and pitch, and what he calls the "common sensibles," the character of things which can be perceived by more than one organ. These are enumerated as size, form or shape, number, motion (and its opposite rest), being. (The addition of this last is, of course, meant to account for our conviction that any perceived colour, taste, or other quality is a reality and not a delusion.) The list corresponds very closely with one given by Plato of the "things which the mind perceives by herself without the help of any organ," i.e. of the leading determinations of sensible things which are due not to sense but to understanding. It was an unfortunate innovation to regard the discernment of number or movement, which obviously demand intellectual processes such as counting and comparison, as performed immediately by "sense," and to assign the apprehension of number, movement, figure to a central "organ." This organ he finds in the heart. The theory is that when the "special organs" of the senses are stimulated, they in turn communicate movements to the blood and "animal spirits" (i.e. the vapours supposed to be produced from the blood by animal heat). These movements are propagated inwards to the heart, where they all meet. This is supposed to account for the important fact that, though our sensations are so many and diverse, we are conscious of our own unity as the subjects apprehending all this variety. The unity of the perceiving subject is thus made to depend on the unity of the ultimate "organ of sensation," the heart. Further, when once a type of motion has been set up in any sense-organ at the periphery of the body it will be propagated inward to the "common sensorium" in the heart. The motions set up by stimulation, e.g. of the eye and of the skin, are partly different, partly the same (viz. in so far as they are determined by the number, shape, size, movement of the external stimuli). Hence in the heart itself the stimulation on which perception of number or size depends is one and the same whether it has been transmitted from the eye or from the skin! Awareness of lapse of time is also regarded as a function of the "common sense-organ," since it is the "common sensory" which perceives motion, and lapse of time is apprehended only in the apprehension of motion. Thus, in respect of the inclusion of geometrical form and lapse of time among the "common sensibles," there is a certain resemblance between Aristotle's doctrine and Kant's theory that recognition of spatial and temporal order is a function not of understanding but of "pure" sense. It is further held that to be aware that one is perceiving (self-consciousness) and to discriminate between the different classes of "special" sense-perception must also be functions of the "common sense-organ." Thus Aristotle makes the mistake of treating the most fundamental acts of intelligent reflection as precisely on a par, from the point of view of the theory of knowledge, with awareness of colour or sound.

A more legitimate function assigned to the "common sensorium" in the heart is that "fantasy," the formation of mental imagery, depends on its activity. The simplest kind of "image," the pure memory-image left behind after the object directly arousing perception has ceased to stimulate, is due to the persistence of the movements set up in the heart after the sensory process in the peripheral organ is over. Since Aristotle denies the possibility of thinking without the aid of memory-images, this function of the "common sensorium" is the indispensable basis of mental recall, anticipation, and thought. Neither "experience," i.e. a general conviction which results from the frequent repetition of similar perceptions, nor thought can arise in any animal in which sense-stimulation does not leave such "traces" behind it. Similarly "free imagery," the existence of trains of imagination not tied down to the reproduction of an actual order of sensations, is accounted for by the consideration that "chance coincidence" may lead to the stimulation of the heart in the same way in which it might have been stimulated by actual sensation-processes. Sleeping and waking and the experiences of dream-life are likewise due to changes in the functioning of the "common sense-organ," brought about partly by fatigue in the superficial sense-organs, partly by qualitative changes in the blood and "animal spirits" caused by the processes of nutrition and digestion. Probably Aristotle's best scientific work in psychology is contained in the series of small essays in which this theory of memory and its imagery is worked out. (Aristotle's language about the "common sensibles" is, of course, the source of our expression "common sense," which, however, has an entirely different meaning. The shifting of sense has apparently been effected through Cicero's employment of the phrase sensus communis to mean tactful sympathy, the feeling of fellowship with our kind on which the Stoic philosophers laid so much stress.)

Thought.--Though thinking is impossible except by the use of imagery, to think is not merely to possess trains of imagery, or even to be aware of possessing them. Thinking means understanding the meaning of such mental imagery and arriving through the understanding at knowledge of the structure of the real world. How this process of interpreting mental imagery and reaching valid truth is achieved with greater and greater success until it culminates in the apprehension of the supreme principles of philosophy we have seen in dealing with the Aristotelian theory of knowledge. From the point of view of the "physicist" who is concerned with thinking simply as a type of natural process, the relation of "understanding" to the mental imagery just described is analogous to that of sensation to sensible qualities. The objects which thinking apprehends are the universal types of relation by which the world of things is pervaded. The process of thinking is one in which this system of universal relations is reproduced "by way of idea" in the mind of the thinker. The "understanding" thus stands to its objects as matter to form. The process of getting actually to understand the world is one in which our "thought" or "understanding" steadily receives completer determination and "form" from its contemplation of reality. In this sense, the process is one in which the understanding may be said to be passive in knowledge. It is passive because it is the subject which, at every fresh stage in the progress to knowledge, is being quite literally "informed" by the action of the real world through the sensation and imagery. Hence Aristotle says that, in order that the understanding may be correctly "informed" by its contact with its objects, it must, before the process begins, have no determinate character of its own. It must be simply a capacity for apprehending the types of interconnection. "What is called the intelligence--I mean that with which the soul thinks and understands--is not an actual thing until it thinks." (This is meant to exclude any doctrine which credits the "understanding" with either furniture of its own such as "innate ideas," or a specific structure of its own. If the results of our thinking arose partly from the structure of the world of objects and partly from inherent laws of the "structure of mind," our thought at its best would not reproduce the universal "forms" or "types" of interconnection as they really are, but would distort them, as the shapes of things are distorted when we see them through a lens of high refractive index.) Thus, though Aristotle differs from the modern empiricists in holding that "universals" realty exist "in" things, and are the links of connection between them, he agrees with the empiricist that knowledge is not the resultant of a combination of "facts" on the one side and "fundamental laws of the mind's working" on the other. At the outset the "understanding" has no structure; it develops a structure for itself in the same process, and to the same degree, in which it apprehends the "facts." Hence the "understanding" only is real in the actual process of understanding its objects, and again in a sense the understanding and the things it understands are one. Only we must qualify this last statement by saying that it is only "potentially" that the understanding is the forms which it apprehends. Aristotle does not mean by this that such things as horses and oxen are thoughts or "ideas." By the things with which "understanding" is said to be one he means the "forms" which we apprehend when we actually understand the world or any part of it, the truths of science. His point then is that the actual thinking of these truths and the truths themselves do not exist apart from one another. "Science" does not mean certain things written down in a book; it means a mind engaged in thinking and knowing things, and of the mind itself, considered out of its relation to the actual life of thinking the truths of science, we can say no more than that it is a name for the fact that we are capable of achieving such thought.

The Active Intelligence.--So far Aristotle's account of thought has been plain sailing. Thought has been considered as the final and highest development of the vital functions of the organism, and hence as something inseparable from the lower functions of nutrition and sensitive life. The existence of a thought which is not a function of a living body, and which is not "passive," has been absolutely excluded. But at this point we are suddenly met by the most startling of all the inconsistencies between the naturalistic and the "spiritualist" strains in Aristotle's philosophy. In a few broken lines he tells us that there is another sense of the word "thought" in which "thought" actually creates the truths it understands, just as light may be said to make the colours which we see by its aid. "And this intelligence," he adds, "is separable from matter, and impassive and unmixed, being in its essential nature an activity.... It has no intermission in its thinking. It is only in separation from matter that it is fully itself, and it alone is immortal and everlasting ... while the passive intelligence is perishable and does not think at all, apart from this." The meaning of this is not made clear by Aristotle himself, and the interpretation was disputed even among the philosopher's personal disciples.

One important attempt to clear up the difficulty is that made by Alexander of Aphrodisias, the greatest of the commentators on Aristotle, in the second century A.D. Alexander said, as Aristotle has not done, that the "active intelligence" is numerically the same in all men, and is identical with God. Thus, all that is specifically human in each of us is the "passive intelligence" or capacity for being enlightened by God's activity upon us. The advantage of the view is, that it removes the "active intelligence" altogether from the purview of psychology, which then becomes a purely naturalistic science. The great Arabian Aristotelian, Averroes (Ibn Roschd) of Cordova, in the twelfth century, went still further in the direction of naturalism. Since the "active" and "passive" intelligence can only be separated by a logical abstraction, he inferred that men, speaking strictly, do not think at all; there is only one and the same individual intelligence in the universe, and all that we call our thinking is really not ours but God's. The great Christian scholastics of the following century in general read Aristotle through the eyes of Averroes, "the Commentator," as St. Thomas calls him, "Averrois che il gran commento feo," as Dante says. But their theology compelled them to disavow his doctrine of the "active intelligence," against which they could also bring, as St. Thomas does, the telling argument that Aristotle could never have meant to say that there really is no such thing as human intelligence. Hence arose a third interpretation, the Thomist, according to which the "active intelligence" is neither God nor the same for all men, but is the highest and most rational "part" of the individual human soul, which has no bodily "organ."

CHAPTER V

PRACTICAL PHILOSOPHY

Hitherto we have been concerned with the speculative branches of knowledge, we have now to turn to practice. Practice, too, is an activity of thought, but an activity which is never satisfied by the process of thinking itself. In practice our thinking is always directed towards the production of some result other than true thought itself. As in engineering it is not enough to find a solution of the problem how to build a bridge over a given river capable of sustaining a given strain, so in directing our thought on the problems of human conduct and the organisation of society we aim at something more than the understanding of human life. In the one case what we aim at is the construction of the bridge; in the other it is the production of goodness in ourselves and our fellow-men, and the establishment of right social relations in the state. Aristotle is careful to insist on this point throughout his whole treatment of moral and social problems. The principal object of his lectures on conduct is not to tell his hearers what goodness is, but to make them good, and similarly it is quite plain that Politics was intended as a text-book for legislators. In close connection with this practical object stands his theory of the kind of truth which must be looked for in ethics and politics. He warns us against expecting precepts which have the exact and universal rigidity of the truths of speculative science. Practical science has to do with the affairs of men's lives, matters which are highly complex and variable, in a word, with "what may be otherwise." Hence we must be content if we can lay down precepts which hold good in the main, just as in medicine we do not expect to find directions which will effect a cure in all cases, but are content with general directions which require to be adapted to special cases by the experience and judgment of the practitioner. The object of practical science then is to formulate rules which will guide us in obtaining our various ends. Now when we consider these ends we see at once that some are subordinate to others. The manufacture of small-arms may be the end at which their maker aims, but it is to the military man a mere means to his end, which is the effective use of them. Successful use of arms is again the end of the professional soldier, but it is a mere means among others to the statesman. Further, it is the military men who use the arms from whom the manufacturer has to take his directions as to the kind of arms that are wanted, and again it is the statesman to whom the professional soldiers have to look for directions as to when and with what general objects in view they shall fight. So the art which uses the things produced by another art is the superior and directing art; the art which makes the things, the inferior and subordinate art. Hence the supreme practical art is politics, since it is the art which uses the products turned out by all other arts as means to its ends. It is the business of politics, the art of the statesman, to prescribe to the practitioners of all other arts and professions the lines on which and the conditions under which they shall exercise their vocation with a view to securing the supreme practical end, the well-being of the community. Among the other professions and arts which make the materials the statesman employs, the profession of the educator stands foremost. The statesman is bound to demand certain qualities of mind and character in the individual citizens. The production of these mental and moral qualities must therefore be the work of the educator. It thus becomes an important branch of politics to specify the kind of mental and moral qualities which a statesman should require the educator to produce in his pupils.

It is this branch of politics which Aristotle discusses in his Ethics. He never contemplates a study of the individual's good apart from politics, the study of the good of the society. What then is the good or the best kind of life for an individual member of society? Aristotle answers that as far as the mere name is concerned, there is a general agreement to call the best life, Eudaimonia, Happiness. But the real problem is one of fact. What kind of life deserves to be called happiness? Plato had laid it down that the happy life must satisfy three conditions. It must be desirable for its own sake, it must be sufficient of itself to satisfy us, and it must be the life a wise man would prefer to any other. The question is, What general formula can we find which will define the life which satisfies these conditions? To find the answer we have to consider what Plato and Aristotle call the work or function of man. By the work of anything we mean what can only be done by it, or by it better than by anything else. Thus the work of the eye is to see. You cannot see with any other organ, and when the eye does this work of seeing well you say it is a good eye. So we may say of any living being that its work is to live, and that it is a good being when it does this work of living efficiently. To do its own work efficiently is the excellence or virtue of the thing. The excellence or virtue of a man will thus be to live efficiently, but since life can be manifested at different levels, if we would know what man's work is we must ask whether there is not some form of life which can only be lived by man. Now the life which consists in merely feeding and growing belongs to all organisms and can be lived with equal vigour by them all. There is, however, a kind of life which can only be lived by man, the life which consists in conscious direction of one's actions by a rule. It is the work of man to live this kind of life, and his happiness consists in living it efficiently and well. So we may give as the definition of human well-being that it is "an active life in accord with excellence, or if there are more forms of excellence than one, in accord with the best and completest of them"; and we must add "in a complete life" to show that mere promise not crowned by performance does not suffice to entitle man's life to be called happy. We can see that this definition satisfies Plato's three conditions. A vigorous and active living in a way which calls into play the specifically human capacities of man is desirable for its own sake, and preferable to any other life which could be proposed to us. It too is the only life which can permanently satisfy men, but we must add that if such a life is to be lived adequately certain advantages of fortune must be presupposed. We cannot fully live a life of this kind if we are prevented from exercising our capacities by lack of means or health or friends and associates, and even the calamities which arise in the course of events may be so crushing as to hinder a man, for a time, from putting forth his full powers. These external good things are not constituents of happiness, but merely necessary conditions of that exercise of our own capacities which is the happy life.

In our definition of the happy life we said that it was one of activity in accord with goodness or excellence, and we left it an open question whether there are more kinds of such goodness than one. On consideration we see that two kinds of goodness or excellence are required in living the happy life. The happy life for man is a life of conscious following of a rule. To live it well, then, you need to know what the right rule to follow is, and you need also to follow it. There are persons who deliberately follow a wrong rule of life--the wicked. There are others who know what the right rule is but fail to follow it because their tempers and appetites are unruly--the morally weak. To live the happy life, then, two sorts of goodness are required. You must have a good judgment as to what the right rule is (or if you cannot find it out for yourself, you must at least be able to recognise it when it is laid down by some one else, the teacher or lawgiver), and you must have your appetites, feelings, and emotions generally so trained that they obey the rule. Hence excellence, goodness, or virtue is divided into goodness of intellect and goodness of character (moral goodness), the word character being used for the complex of tempers, feelings, and the affective side of human nature generally. In education goodness of character has to be produced by training and discipline before goodness of intellect can be imparted. The young generally have to be trained to obey the right rule before they can see for themselves that it is the right rule, and if a man's tempers and passions are not first schooled into actual obedience to the rule he will in most cases never see that it is the right rule at all. Hence Aristotle next goes on to discuss the general character of the kind of goodness he calls goodness of character, the right state of the feelings and passions.

The first step towards understanding what goodness of character is is to consider the way in which it is actually produced. We are not born with this goodness of tempers and feelings ready made, nor yet do we obtain it by theoretical instruction; it is a result of a training and discipline of the feelings and impulses. The possibility of such a training is due to the fact that feelings and impulses are rational capacities, and a rational capacity can be developed into either of two contrasted activities according to the training it receives. You cannot train stones to fall upwards, but you can train a hot temper to display itself either in the form of righteous resentment of wrong-doing or in that of violent defiance of all authority. Our natural emotions and impulses are in themselves neither good nor bad; they are the raw material out of which training makes good or bad character according to the direction it gives to them. The effect of training is to convert the indeterminate tendency into a fixed habit. We may say, then, that moral goodness is a fixed state of the soul produced by habituation. By being trained in habits of endurance, self-mastery, and fair dealing, we acquire the kind of character to which it is pleasing to act bravely, continently, and fairly, and disagreeable to act unfairly, profligately, or like a coward. When habituation has brought about this result the moral excellences in question have become part of our inmost self and we are in full possession of goodness of character. In a word, it is by repeated doing of right acts that we acquire the right kind of character.

But what general characteristics distinguish right acts and right habits from wrong ones? Aristotle is guided in answering the question by an analogy which is really at the bottom of all Greek thinking on morality. The thought is that goodness is in the soul what health and fitness are in the body, and that the preceptor is for the soul what the physician or the trainer is for the body. Now it was a well-known medical theory, favoured by both Plato and Aristotle, that health in the body means a condition of balance or equilibration among the elements of which it is composed. When the hot and the cold, the moist and the dry in the composition of the human frame exactly balance one another, the body is in perfect health. Hence the object of the regimen of the physician or the trainer is to produce and maintain a proper balance or proportion between the ingredients of the body. Any course which disturbs this balance is injurious to health and strength. You damage your health if you take too much food or exercise, and also if you take too little. The same thing is true of health in the soul. Our soul's health may be injured by allowing too much or too little play to any of our natural impulses or feelings. We may lay it down, then, that the kind of training which gives rise to a good habit is training in the avoidance of the opposite errors of the too much and the too little. And since the effect of training is to produce habits which issue in the spontaneous performance of the same kind of acts by which the habits were acquired, we may say not merely that goodness of character is produced by acts which exhibit a proper balance or mean, but that it is a settled habit of acting so as to exhibit the same balance or proportion. Hence the formal definition of goodness of character is that it is "a settled condition of the soul which wills or chooses the mean relatively to ourselves, this mean being determined by a rule or whatever we like to call that by which the wise man determines it."

There are several points in this definition of the mean upon which moral virtue depends of which we must take note unless we are to misunderstand Aristotle seriously. To begin with, the definition expressly says that "moral goodness is a state of will or choice." Thus it is not enough that one should follow the rule of the mean outwardly in one's actions; one's personal will must be regulated by it. Goodness of character is inward; it is not merely outward. Next we must not suppose that Aristotle means that the "just enough" is the same for all our feelings, that every impulse has a moral right to the same authority in shaping our conduct as any other. How much or how little is the just enough in connection with a given spring of action is one of the things which the wise man's rule has to determine, just as the wise physician's rule may determine that a very little quantity is the just enough in the case of some articles of diet or curative drugs, while in the case of others the just enough may be a considerable amount. Also the right mean is not the same for every one. What we have to attain is the mean relatively to ourselves, and this will be different for persons of different constitutions and in different conditions. It is this relativity of the just enough to the individual's personality and circumstances which makes it impossible to lay down precise rules of conduct applicable alike to everybody, and renders the practical attainment of goodness so hard. It is my duty to spend some part of my income in buying books on philosophy, but no general rule will tell me what percentage of my income is the right amount for me to spend in this way. That depends on a host of considerations, such as the excess of my income above my necessary expenses and the like. Or again, the just enough may vary with the same man according to the circumstances of the particular case. No rule of thumb application of a formula will decide such problems. Hence Aristotle insists that the right mean in the individual case has always to be determined by immediate insight. This is precisely why goodness of intellect needs to be added to goodness of character. His meaning is well brought out by an illustration which I borrow from Professor Burnet. "On a given occasion there will be a temperature which is just right for my morning bath. If the bath is hotter than this, it will be too hot; if it is colder, it will be too cold. But as this just right temperature varies with the condition of my body, it cannot be ascertained by simply using a thermometer. If I am in good general health I shall, however, know by the feel of the water when the temperature is right. So if I am in good moral health I shall know, without appealing to a formal code of maxims, what is the right degree, e.g. of indignation to show in a given case, how it should be shown and towards whom." Thus we see why Aristotle demands goodness of character as a preliminary condition of goodness of intellect or judgment in moral matters. Finally, if we ask by what rule the mean is determined, the answer will be that the rule is the judgment of the legislator who determines what is the right mean by his knowledge of the conditions on which the well-being of the community depends. He then embodies his insight in the laws which he makes and the regulations he imposes on the educators of youth. The final aim of education in goodness is to make our immediate judgment as to what is right coincide with the spirit of a wise legislation.

The introduction of the reference to will or choice into the definition of goodness of character leads Aristotle to consider the relation of will to conduct. His main object is to escape the paradoxical doctrine which superficial students might derive from the works of Plato, that wrong-doing is always well-meaning ignorance. Aristotle's point is that it is the condition of will revealed by men's acts which is the real object of our approval or blame. This is because in voluntary action the man himself is the efficient cause of his act. Hence the law recognises only two grounds on which a man may plead, that he is not answerable for what he does. (1) Actual physical compulsion by force majeure. (2) Ignorance, not due to the man's own previous negligence, of some circumstances material to the issue. When either of these pleas can be made with truth the man does not really contribute by his choice to the resulting act, and therefore is not really its cause. But a plea of ignorance of the general laws of morality does not excuse. I cannot escape responsibility for a murder by pleading that I did not know that murder is wrong. Such a plea does not exempt me from having been the cause of the murder; it only shows that my moral principles are depraved.

More precisely will is a process which has both an intellectual and an appetitive element. The appetitive element is our wish for some result. The intellectual factor is the calculation of the steps by which that result may be obtained. When we wish for the result we begin to consider how it might be brought about, and we continue our analysis until we find that the chain of conditions requisite may be started by the performance of some act now in our power to do. Will may thus be defined as the deliberate appetition of something within our power, and the very definition shows that our choice is an efficient cause of the acts we choose to do. This is why we rightly regard men as responsible or answerable for their acts of choice, good and bad alike.

From the analysis of goodness of character, we proceed to that of goodness of intellect. The important point is to decide which of all the forms of goodness of intellect is that which must be combined with goodness of character to make a man fit to be a citizen of the state. It must be a kind of intellectual excellence which makes a man see what the right rule by which the mean is determined is. Now when we come to consider the different excellences of intellect we find that they all fall under one of two heads, theoretical or speculative wisdom and practical wisdom.

Theoretical wisdom is contained in the sciences which give us universal truths about the fixed and unalterable relations of the things in the universe, or, as we should say, which teach us the laws of Nature. Its method is syllogism, the function of which is to make us see how the more complex truths are implied in simpler principles. Practical wisdom is intelligence as employed in controlling and directing human life to the production of the happy life for a community, and it is this form of intellectual excellence which we require of the statesman. It is required of him not only that he should know in general what things are good for man, but also that he should be able to judge correctly that in given circumstances such and such an act is the one which will secure the good. He must not only know the right rule itself, which corresponds to the major premiss of syllogism in theoretical science, but he must understand the character of particular acts so as to see that they fall under the right rule. Thus the method of practical wisdom will be analogous to that of theoretical wisdom. In both cases what we have to do is to see that certain special facts are cases of a general law or rule. Hence Aristotle calls the method of practical wisdom the practical syllogism or syllogism of action, since its peculiarity is that what issues from the putting together of the premisses is not an assertion but the performance of an act. In the syllogism of action, the conclusion, that is to say, the performance of a given act, just as in the syllogism of theory, is connected with the rule given in the major premiss by a statement of fact; thus e.g. the performance of a specific act such as the writing of this book is connected with the general rule what helps to spread knowledge ought to be done by the conviction that the writing of this book helps to spread knowledge. Our perception of such a fact is like a sense-perception in its directness and immediacy. We see therefore that the kind of intellectual excellence which the statesman must possess embraces at once a right conception of the general character of the life which is best for man, because it calls into play his specific capacities as a human being, and also a sound judgment in virtue of which he sees correctly that particular acts are expressions of this good for man. This, then, is what we mean by practical wisdom.

So far, then, it would seem that the best life for man is just the life of co-operation in the life of the state, which man, being the only political animal or animal capable of life in a state, has as his peculiar work, and as if the end of all moral education should be to make us good and efficient citizens. But in the Ethics, as elsewhere, the end of Aristotle's argument has a way of forgetting the beginning. We find that there is after all a still higher life open to man than that of public affairs. Affairs and business of all kinds are only undertaken as means to getting leisure, just as civilised men go to war, not for the love of war itself, but to secure peace. The highest aim of life, then, is not the carrying on of political business for its own sake, but the worthy and noble employment of leisure, the periods in which we are our own masters. It has the advantage that it depends more purely on ourselves and our own internal resources than any other life of which we know, for it needs very little equipment with external goods as compared with any form of the life of action. It calls into play the very highest of our own capacities as intelligent beings, and for that very reason the active living of it is attended with the purest of all pleasures. In it, moreover, we enter at intervals and for a little while, so far as the conditions of our mundane existence allow, into the life which God enjoys through an unbroken eternity. Thus we reach the curious paradox that while the life of contemplation is said to be that of our truest self, it is also maintained that this highest and happiest life is one which we live, not in respect of being human, but in respect of having a divine something in us. When we ask what this life of contemplation includes, we see from references in the Politics that it includes the genuinely æsthetic appreciation of good literature and music and pictorial and plastic art, but there can be no doubt that what bulks most largely in Aristotle's mind is the active pursuit of science for its own sake, particularly of such studies as First Philosophy and Physics, which deal with the fundamental structure of the universe. Aristotle thus definitely ends by placing the life of the scholar and the student on the very summit of felicity.

It is from this doctrine that mediæval Christianity derives its opposition between the vita contemplativa and vita activa and its preference for the former, though in the mediæval mind the contemplative life has come to mean generally a kind of brooding over theological speculations and of absorption in mystical ecstasy very foreign to the spirit of Aristotle. The types by which the contrast of the two lives is illustrated, Rachael and Leah, Mary and Martha, are familiar to all readers of Christian literature.

+The Theory of the State+.--Man is by nature a political animal, a being who can only develop his capacities by sharing in the life of a community. Hence Aristotle definitely rejects the view that the state or society is a mere creature of convention or agreement, an institution made by compact between individuals for certain special ends, not growing naturally out of the universal demands and aspirations of humanity. Mankind, he urges, have never existed at all as isolated individuals. Some rudimentary form of social organisation is to be found wherever men are to be found. The actual stages in the development of social organisation have been three--the family, the village community, the city state. In the very rudest forms of social life known to us, the patriarchal family, not the individual, is the social unit. Men lived at first in separate families under the control of the head of the family. Now a family is made up in its simplest form of at least three persons, a man, his wife, and a servant or slave to do the hard work, though very poor men often have to replace the servant by an ox as the drudge of all work. Children when they come swell the number, and thus we see the beginnings of complex social relations of subordination in the family itself. It involves three such distinct relations, that of husband and wife, that of parent and child, that of master and man. The family passes into the village community, partly by the tendency of several families of common descent to remain together under the direction of the oldest male member of the group, partly by the association of a number of distinct families for purposes of mutual help and protection against common dangers. Neither of these forms of association, however, makes adequate provision for the most permanent needs of human nature. Complete security for a permanent supply of material necessaries and adequate protection only come when a number of such scattered communities pool their resources, and surround themselves with a city wall. The city state, which has come into being in this way, proves adequate to provide from its own internal resources for all the spiritual as well as the material needs of its members. Hence the independent city state does not grow as civilisation advances into any higher form of organisation, as the family and village grew into it. It is the end, the last word of social progress. It is amazing to us that this piece of cheap conservatism should have been uttered at the very time when the system of independent city states had visibly broken down, and a former pupil of Aristotle himself was founding a gigantic empire to take their place as the vehicle of civilisation.

The end for which the state exists is not merely its own self-perpetuation. As we have seen, Aristotle assigns a higher value to the life of the student than to the life of practical affairs. Since it is only in the civilised state that the student can pursue his vocation, the ultimate reason for which the state exists is to educate its citizens in such a way as shall fit them to make the noble use of leisure. In the end the state itself is a means to the spiritual cultivation of its individual members. This implies that the chosen few, who have a vocation to make full use of the opportunities provided for leading this life of noble leisure, are the real end for the sake of which society exists. The other citizens who have no qualification for any life higher than that of business and affairs are making the most of themselves in devoting their lives to the conduct and maintenance of the organisation whose full advantages they are unequal to share in. It is from this point of view also that Aristotle treats the social problem of the existence of a class whose whole life is spent in doing the hard work of society, and thus setting the citizen body free to make the best use it can of leisure. In the conditions of life in the Greek world this class consisted mainly of slaves, and thus the problem Aristotle has to face is the moral justifiability of slavery. We must remember that he knew slavery only in its comparatively humane Hellenic form. The slaves of whom he speaks were household servants and assistants in small businesses. He had not before his eyes the system of enormous industries carried on by huge gangs of slaves under conditions of revolting degradation which disgraced the later Roman Republic and the early Roman Empire, or the Southern States of North America. His problems are in all essentials much the same as those which concern us to-day in connection with the social position of the classes who do the hard bodily work of the community.

Much consideration is given in the Politics to the classification of the different types of constitution possible for the city-state. The current view was that there are three main types distinguished by the number of persons who form the sovereign political authority, monarchy, in which sovereign power belongs to a single person; oligarchy, in which it is in the hands of a select few; democracy, in which it is enjoyed by the whole body of the citizens. Aristotle observes, correctly, that the really fundamental distinction between a Greek oligarchy and a Greek democracy was that the former was government by the propertied classes, the latter government by the masses. Hence the watchword of democracy was always that all political rights should belong equally to all citizens, that of oligarchy that a man's political status should be graded according to his "stake in the country." Both ideals are, according to him, equally mistaken, since the real end of government, which both overlook, is the promotion of the "good life." In a state which recognises this ideal, an aristocracy or government by the best, only the "best" men will possess the full rights of citizenship, whether they are many or few. There might even be a monarch at the head of such a state, if it happened to contain some one man of outstanding intellectual and moral worth. Such a state should be the very opposite of a great imperial power. It should, that its cultivation may be the more intensive, be as small as is compatible with complete independence of outside communities for its material and spiritual sustenance, and its territory should only be large enough to provide its members with the permanent possibility of ample leisure, so long as they are content with plain and frugal living. Though it ought not, for military and other reasons, to be cut off from communication with the sea, the great military and commercial high road of the Greek world, it ought not to be near enough to the coast to run any risk of imperilling its moral cultivation by becoming a great emporium, like the Athens of Pericles. In the organisation of the society care should be taken to exclude the agricultural and industrial population from full citizenship, which carries with it the right to appoint and to be appointed as administrative magistrates. This is because these classes, having no opportunity for the worthy employment of leisure, cannot be trusted to administer the state for the high ends which it is its true function to further.

Thus Aristotle's political ideal is that of a small but leisured and highly cultivated aristocracy, without large fortunes or any remarkable differences in material wealth, free from the spirit of adventure and enterprise, pursuing the arts and sciences quietly while its material needs are supplied by the labour of a class excluded from citizenship, kindly treated but without prospects. Weimar, in the days when Thackeray knew it as a lad, would apparently reproduce the ideal better than any other modern state one can think of.

The object of the Politics is, however, not merely to discuss the ideal state but to give practical advice to men who might be looking forward to actual political life, and would therefore largely have to be content with making the best of existing institutions. In the absence of the ideal aristocracy, Aristotle's preference is for what he calls Polity or constitutional government, a sort of compromise between oligarchy and democracy. Of course a practical statesman may have to work with a theoretically undesirable constitution, such as an oligarchy or an unqualified democracy. But it is only in an ideal constitution that the education which makes its subject a good man, in the philosopher's sense of the word, will also make him a good citizen. If the constitution is bad, then the education best fitted to make a man loyal to it may have to be very different from that which you would choose to make him a good man. The discussion of the kind of education desirable for the best kind of state, in which to be a loyal citizen and to be a good man are the same thing, is perhaps the most permanently valuable part of the Politics. Though Aristotle's writings on "practical" philosophy have been more read in modern times than any other part of his works, they are far from being his best and most thorough performances. In no department of his thought is he quite so slavishly dependent on his master Plato as in the theory of the "good for man" and the character of "moral" excellence. No Aristotelian work is quite so commonplace in its handling of a vast subject as the Politics. In truth his interest in these social questions is not of the deepest. He is, in accordance with his view of the superiority of "theoretical science," entirely devoid of the spirit of the social reformer. What he really cares about is "theology" and "physics," and the fact that the objects of the educational regulations of the Politics are all designed to encourage the study of these "theoretical" sciences, makes this section of the Politics still one of the most valuable expositions of the aims and requirements of a "liberal" education.

All education must be under public control, and education must be universal and compulsory. Public control is necessary, not merely to avoid educational anarchy, but because it is a matter of importance to the community that its future citizens should be trained in the way which will make them most loyal to the constitution and the ends it is designed to subserve. Even in one of the "bad" types of state, where the life which the constitution tends to foster is not the highest, the legislator's business is to see that education is directed towards fostering the "spirit of the constitution." There is to be an "atmosphere" which impregnates the whole of the teaching, and it is to be an "atmosphere" of public spirit. The only advantage which Aristotle sees in private education is that it allows of more modification of programme to meet the special needs of the individual pupil than a rigid state education which is to be the same for all. The actual regulations which Aristotle lays down are not very different from those of Plato. Both philosophers hold that "primary" education, in the early years of life, should aim partly at promoting bodily health and growth by a proper system of physical exercises, partly at influencing character and giving a refined and elevated tone to the mind by the study of letters, art, and music. Both agree that this should be followed in the later "teens" by two or three years of specially rigorous systematic military training combined with a taste of actual service in the less exhausting and less dangerous parts of a soldier's duty. It is only after this, at about the age at which young men now take a "university" course, that Plato and Aristotle would have the serious scientific training of the intellect begun. The Politics leaves the subject just at the point where the young men are ready to undergo their special military training. Thus we do not know with certainty what scientific curriculum Aristotle would have recommended, though we may safely guess that it would have contained comparatively little pure mathematics, but a great deal of astronomy, cosmology, and biology.