J. M. WILSON AND T. FOWLER, PRINCIPLES OF MORALS. 589

This review has reached such length that little more than mention can be made of the third section of the book. I do not altogether regret this, as I should be compelled chiefly to criticise, and, in matters of speculation, criticism is not usually profitable. The subjects of the four chapters are : " The Faculties of the Mind, and its Unity," "The Development of the Mind," " Beal Connexion of Brain and Mind " and " The Mind as Eeal Being ". Prof. Ladd argues that mind is "a real unit being," standing in causal relations with the brain. It is not easy to bring such a view into accord with the physical theory of the conservation of energy. Prof. Ladd defines energy as "that which moves or tends to move the elementary atoms, or their aggregations, into molecules and masses " ! A superficial reading might find Prof. Ladd's views identical with Lotze's. Lotze, however, saves him- self from a materialistic dualism through his monadology. Prof. Ladd concludes his book by leaving the full consideration of " the first and last things of the Mind its origin and destiny, its mor- tality or corruptibility," "to Eational Psychology, to Ethics, to Metaphysics and to Theology ". The preparation of a book on physiological psychology, at a time when both physiology and psychology are confused and irregularly advancing, is a task of the utmost difficulty. Such a book cannot but contain matters open to criticism, and these it is the duty of the reviewer to notice. In the present case, however, it is equally a duty to give the sincere praise which the book deserves. We are not only under great obligation to Prof. Ladd for his care and labour, but owe hearty recognition to the mastery and ability which have enabled him to prepare a work of real value and importance. ' ^ McK< CATTELL> The Principles of Morals (Introductory Chapters). By JOHN MATTHIAS WILSON, B.D., late President of Corpus Christi College and Whyte's Professor of Moral Philosophy in the University of Oxford, and THOMAS FOWLER, D.D., President of Corpus Christi College and Wykeham Professor of Logic in the University of Oxford, &c. Oxford : Clarendon Press, 1886. Pp. vii, 133. The Principles of Morals. Part II. (Being the Body of the Work). By THOMAS FOWLER, D.D., &c. Oxford : Clarendon Press, 1887. Pp. xii., 370. The first and smaller of these two volumes represents the portion of the work which was completed before the death of Prof. Wilson. For the second Prof. Fowler is alone responsible, though considerable portions of it (which are exactly indicated) are " either based on written or oral communications " received from Prof. Wilson, "or were jointly composed" by the two authors. The first volume is mainly historical, though it begins with chapters