First, then, for the psychological side. We may well begin by accepting the ordinary tripartite division of human nature which has passed current ever since the time of Aristotle. Apart from the broad fact of life which is common to the whole organic world, the faculties of man may be classified under the three heads of sensation, which he undoubtedly shares with the other animals, emotion, which he shares with them in a higher and more developed degree, and reason, which, so far as our present knowledge attests, he possesses as a sole and special prerogative. There is no need to enter here into any vexed questions of limit and demarcation. A philosophy of evolution may some day show that all human faculties spring from a common source: it has not yet done so; and whether it succeed or fail, the fact remains that in our present condition the three classes are different both in property and in function. Emotion may be partly dependent on the nervous system, but it cannot be summed up in terms of nervous energy: still less can the work of the mind be resolved into formulæ of chemical change and molecular movement. The spiritual principle in man is no more to be confounded with the brain which it employs as its instrument, than the sculptor with his mallet and chisel, or the violinist with his Stradivarius.
Further, the rational principle may itself be regarded as twofold. On the lower side there is a discursive intellect, which weighs evidence and compares the reports of the senses, which is logical, inferential, ratiocinative: on the higher side there is faculty of pure intuition, whence come our axioms, our great Religious truths, our first principles of art and science. Here again we must wait to determine whether this distinction be one of aspect or faculty, until we are certain that we know the meaning of the two terms: at present it is only necessary to note that the distinction is recognised as real by psychologists, no less diverse in aim than Aristotle and Hegel. Faith to the Theologian is the exercise of the intuitive reason on divine things. Thought to the metaphysician is the faculty behind inference with which Being itself is correlative. But there is no need to call further testimony. It is enough to say in plain words, that if we know conclusions which we can prove, we must have some faculty of knowledge which deals with proof: if we know axiomatic laws which we cannot prove, we must have some faculty of knowledge which is independent of proof. We know that two straight lines cannot enclose a space: we know that the angles at the base of an isosceles triangle are equal to one another. In these two facts of knowledge the two aspects of reason are exhibited in their simplest exercise.
Now, with this spiritual principle of intuition we have, for the present, nothing further to do. As it is the highest faculty in us, so it is the least capable of analysis; we cannot define it or describe it, or say more than that we are conscious of its existence. 'Everyone,' said Gautier, 'has his measure of inspiration,' and the words, apart from the tone of mockery in which they were uttered, are literally true. Everybody is, at some time or another, affected beyond the reach of words by some great display of beauty or majesty or heroism; and at such moments we feel a true inspiration which is none the less real for being inarticulate. So in Music, the one function of this intuitive principle is the immediate apprehension of vitality in the best work. To one it may be the first hearing of a Beethoven symphony, to another it may be the Messiah, to another some complete and perfect Volkslied; but whatever the object, we cease to reason or criticise, and simply acknowledge it as divine, in virtue of a divine principle in ourselves. The work is a momentary scintillation from the great glowing fire of genius, and we can love it, because the best faculty that we possess is a spark kindled by the same light. Not that in admiring we claim equality. We are dumb poets, 'wanting the accomplishment of verse,' lacking the gift of articulation, which implies a clearer vision and a closer communion with the ideal. But to admire at all, in this true sense of enthusiasm and self-abandonment, is only possible when the highest chord of our nature is struck. Man is never lifted nearer to Heaven than when he bows himself to worship.
Such moments of inspired admiration are of rare occurrence. But it is impossible to mistake them; impossible to confuse them with the careless, unthinking enjoyment of the senses, in which so much of our musical appreciation is supposed to consist. Between the spontaneous reverence for a masterpiece, and the unintelligent pleasure in mere sound, there is as wide a difference as between the two loves of Plato's fable and Titian's picture: the one is a daughter of Urania, the other of mortal parentage and of mortal passion. In our impulse towards beauty, as in all other affections of our nature, the two extreme points lie outside the limits of the discursive reason, and it is with the intervening space that rational analysis can be most profitably occupied. In other words, there is a whole realm of artistic appreciation in which we can resolve our pleasure into its constituent factors, and discover not only what it is that we enjoy, but how our capacity for enjoyment is originated and developed. And as almost all errors of musical judgment spring from carelessness of observation, such analysis will not only possess a scientific interest, it will also supply us with some criterion for estimating the value of separate styles and distinguishing the false and ephemeral from the true and abiding. In a previous essay some attempt was made to sketch roughly and imperfectly the four great corner-stones on which this method should rest: the law of vitality, the law of labour, the law of proportion, and the law of fitness to the matter in hand. It now remains to build upon this foundation, to trace out in some degree the application of these laws, and to discover, if discovery is possible, the axiomata media which these wider generalisations include.
The mode, then, in which we are ordinarily influenced by Music may be roughly classified under three main types of affection. First, there is the purely physical, the effect of bodily pleasure or pain, which is produced on the nervous system by a concurrence or succession of air vibrations, and is analogous to those impressions of the palate, which are translated into taste, or those movements of the optic nerve, which are translated into colour. Secondly, there is the semi-physical, in which, for the mere corporeal excitation of the senses, we have that subtler and more sublimated form of influence which it is usual to comprise under the name of emotion. Here we may find analogy with the vague, half-conscious feeling of melancholy which we experience in reading Shelley's Stanzas written in Dejection, or the throb of courage and hopefulness which, without any thought of the artistic value of the poem, stirs in our heart as an answer to Browning's Prospice. Not, of course, that our appreciation of these two works is merely emotional; to say this would be to deny their position as products of art; but it has its emotional side, of which we are all conscious in a greater or less degree. It is a commonplace of criticism that verse which is religious or patriotic is often estimated entirely out of relation to its artistic worth; and that a poor poem may strike a responsive chord in our nature which leads us to give it an altogether factitious importance. And this error of judgment is due not to the spiritual part of our nature, for that takes artistic form for granted, and rises above it, but to an emotional sympathy with the tenour of the poem which blinds us for the moment to its literary imperfection. So in Music, it does not follow that because we feel ourselves stirred by a certain combination of notes, we are therefore in the presence of a real masterpiece. The passage in question may strike us because it is great, but it may equally do so because we are unintelligent; and though in either case our attitude has its noble aspect, for all genuine admiration is good up to its limits, yet it is a matter of some moment whether we are burning our incense before a true or a false shrine. There is no small difference between being stimulated by some prophetic utterance, and finding our consolation in the sound 'of that blessed word Mesopotamia.'
Third, and most vital of the three, is the rational or logical side, through which we appraise an artistic work, not by any test of sensuous pleasure or emotional stimulus, but by some definite and intelligible scheme of æsthetic laws. To this belongs our appreciation of style, our appreciation of structure, all that we really imply in the word 'criticism.' By this we estimate everything in art, of which the estimation can be reduced to laws, everything that is not confined to a bare statement of personal likes and dislikes. In the two previous forms of affection we are merely passive, the recipients of some mechanical or semi-mechanical impact from outside; in this alone we aid the composer by our own judgment, and respond to his call with a sane and intelligent answer. Grant that the application of logic to art has special and serious dangers, that to its misuse we owe all the pedantry and all the intolerance by which the history of criticism has so often been defaced; it still remains true that the method, if rightly exercised, is the one condition of any sound and scientific analysis. Grant that the highest art and the highest appreciation are both, in a sense, spontaneous, it will be found that they have not disregarded reason, but absorbed it. To touch the most purely spiritual part of man's nature is, ipso facto, to have removed furthest from the purely animal; and it is no very extreme paradox to hold that, if a limit be transcended, it must first have been traversed. So the greatest masterpieces in Music will be found to contain sensuous, emotional and rational factors, and something beside, some divine element of life by which they are animated and inspired. The fourth of these we shall never be able to analyse, but we may, at least, devote a little attention to the organic chemistry of the others.
The sensation of sound is, on its material side, an affection of the auric nerve, under stimulus of regular and periodic air vibrations. The physical pleasure which results from it is entirely dependent on the degree of stimulation, and is therefore conditioned by two variables—the manner of vibration in the air waves, and the particular receptivity of the nerve. It will be convenient, for the sake of clearness, to take these two separately.
The simplest air vibrations may differ from each other in three ways. By their rapidity is determined the pitch of the sound, that is, its distinction of high and low; by their size, the volume of the sound, that is, its distinction of loud and soft; and by their shape, the timbre of the sound, that is, the peculiar quality which distinguishes the 'voices' of the different musical instruments. It does not appear that the pleasurableness of the result is seriously affected by the first two of these, provided that they fall within the limits of clear sensation. No doubt there are at the extreme ends of the gamut notes which we cannot detect without some difficulty, but between them the differences of pitch are recognised by everyone as plain facts, which have little or nothing to do with the agreeableness of the tone. Again, when we are standing near the organ, on which some follower of Master Hugues is 'blaring out the Mode Palestrina,' our ear may be overcharged with sound, but in that case we can no more be said to hear the music than the eye can be said to see when it is dazzled with a sudden splendour of light. Differences of timbre, on the contrary, do seem to imply distinctions of pleasurableness or the reverse. Almost all people of imperfect musical cultivation have their favourite instruments; one enjoys the violin, but cares nothing for the piano; another remains in frozen indifference until he is melted by the human voice; another finds all music comprised in the invigorating skirl of the bagpipes. It must be remembered that such influences are wholly physical. They have nothing to do with artistic appreciation in the proper sense of the term; they are as purely sensuous as our delight in the colour of a flower or the taste of a dish.
Now, the immediate effect of music upon the nervous system is incontestable. It has often been noticed in animals other than man; it is a matter of common observation in children; it has been made the basis of a proposal to use the art as a medicinal agency.[2] And as no two sets of nerves are exactly alike, it follows that in no two organisms will the same effect be produced. If the temperament be highly strung, and if there be no intellectual enjoyment of the art to divert attention, the nerve may be over-stimulated, and the result will be a feeling of pain. As the nerve strengthens, it will grow more tolerant; as education advances, the mind will be occupied with new interests. Questions of form and style will assert their pre-eminence over questions of tone. In a word, body will