Professor Cattell objects that the theories of Darwin and Spencer on the origin of music, describe what probably took place, rather than explain why it was necessary that it should have taken place. As to Spencer’s explanation of harmony, he affirms that it amounts to saying that harmony gives pleasure because it is pleasant. After referring to the connection of harmony with the existence of overtones, Prof. Cattell states that music is not, as commonly supposed, a creation of the imagination, freer than the other arts from a physical basis, but is rather a discovery and a development. All the combinations of music are latent in the sounds Of nature, and the history of music bears witness to the gradual adoption of such as are more remote. The difference in voices rests on the overtones present, and the immense emotional effects of music are due to the fact that music expresses the emotion of the human voice, using and developing those combinations of tones which the voice uses when moved by sorrow and joy, despair and exultation. By the _Coefficient_ of External Reality, Professor Baldwin means the something which attaches to some presentations in virtue of which we attribute reality to them; while others, not having the coefficient, are discredited. Diametrically opposed solutions of this question are held. To one class of writers, the coefficient of the reality of an image is its independence of the will; to another class, the coefficient is subjection to the will. If we make a distinction between a memory-coefficient of reality—that is, the something about a memory which leads us to believe it represents a real experience—and a sensational coefficient, that is, the criterion of present sensational reality, we see that those two kinds of reality differ in their relation to the will. A present sensible reality is not under the control of any will, but a memory coefficient is subjected to will, in the sense that we are able to get the image again as a sensation by repeating the series of voluntary muscular sensations which were associated with it in its first experience. This memory-coefficient of external reality must be distinguished from the coefficient of memory itself; the latter being the feeling that an image has been in consciousness before, i. e. recognition, or sense of familiarity. A true memory is an image which I can get at will by a train of memory-associates, and which, when got, is further subject to my will. (London: Williams & Norgate.) INTERNATIONAL JOURNAL OF ETHICS. July, 1891. Vol. I. NO. 4. CONTENTS: THE MODERN CONCEPTION OF THE SCIENCE OF RELIGION. By Prof. _Edward Caird_. THE FUNCTIONS OF ETHICAL THEORY. By Prof. _James H. Hyslop_. THE MORALITY OF NATIONS. By Prof. _W. R. Sorley_. J. S. MILL’S SCIENCE OF ETHOLOGY. By _James Ward_. VICE AND IMMORALITY. By _R. W. Black_. THE PROGRESS OF POLITICAL ECONOMY SINCE ADAM SMITH. By _Francis W. Newman_.