42. And the opposition of these two kinds of sound is continually dwelt upon by the Greek philosophers, the real fact at the root of all music is the natural expression of a lofty passion for a right cause; that in proportion to the kingliness and force of any personality, the expression either of its joy or suffering becomes measured, chastened, calm, and capable of interpretation only by the majesty of ordered, beautiful, and worded sound. Exactly in proportion to the degree in which we become narrow in the cause and conception of our passions, incontinent in the utterance of them, feeble of perseverance in them, sullied or shameful in the indulgence of them, their expression by musical sound becomes broken, mean, fatuitous, and at last impossible; the measured waves of the air of heaven will not lend themselves to expression of ultimate vice, it must be forever sunk into discordance or silence. And since, as before stated, every work of right art has a tendency to reproduce the ethical state which first developed it, this, which of all the arts is most directly in power of discipline; the first, the simplest, the most effective of all instruments of moral instruction; while in the failure and betrayal of its functions, it becomes the subtlest aid of moral degradation. Music is thus, in her health, the teacher of perfect order, and is the voice of the obedience of angels, and the companion of the course of the spheres of heaven; and in her depravity she is also the teacher of perfect disorder and disobedience, and the Gloria in Excelsis becomes the Marseillaise. In the third section of this volume, I reprint two chapters from another essay of mine ("The Cestus of Aglaia"), on modesty or measure, and on liberty, containing further reference to music in her two powers; and I do this now, because, among the many monstrous and misbegotten fantasies which are the spawn of modern license, perhaps the most impishly opposite to the truth is the conception of music which has rendered possible the writing, by educated persons, and, more strangely yet, the tolerant criticism, of such words as these: "This so persuasive art is the only one that has no didactic efficacy, that engenders no emotions save such as are without issue on the side of moral truth, that expresses nothing of God, nothing of reason, nothing of human liberty." I will not give the author's name; the passage is quoted in the "Westminster Review" for last January [1869].