Page:Philosophical Review Volume 23.djvu/102



These are both interesting books, written by competent scientists, and well suited to introduce the ordinary reader to the scientific conception of evolution. Professor Schmucker gives an exceedingly simple and clear-cut exposition that would be intelligible and interesting to any secondary or normal school student or graduate who cares to know what biologists mean by evolution. He illustrates biological laws with the horse, the English sparrow, and other familiar types. The evolutionary controversies since Darwin are treated in a single chapter, just enough to show that advance has been made and that differences of opinion exist; while the moral and religious questions that must inevitably trouble such a reader are sympathetically treated in the two concluding chapters.

Dr. Herbert's volume, while also popular in its appeal, is much profounder and more comprehensive. It will be hard for those who have not visited English university extension lecture courses, such as those given by the Workers' Educational Association, to believe that this scholarly work is "the outcome of a series of lectures given to a class of working-men and others." The Preface states that the author's purpose is "to present the problem of Evolution comprehensively in all its aspects ... in a simple yet scientific manner." Under the head of "Inorganic Evolution" the rival nebular theories of La Place and Chamberlin, the epochs in geological evolution, radio-activity and the evolution of atoms, and the hypotheses as to the origin of life in relationship to matter are all tersely but clearly stated. More than half the volume is devoted to "Organic Evolution," and in this the writer follows Romanes in first discussing what are considered to be the established "facts of evolution" as regards morphology, embryology, classification, palæontology, and geographical distribution. Subsequently come the "theories of evolution," in which most space is devoted to Darwin and neo-Darwinians, but the positions of Lamarck and neo-Lamarckians, Mendel, De Vries, and others are also impartially stated. The third section of the book, "Super-organic Evolution," discusses mental evolution with reference to the behavior of lower organisms and the rise of instinct and intelligence, the evolution of morals and its relationship to ethics, the evolution of the family, the state, and religion. The book concludes with two chapters on the philosophy of evolution in which the metaphysical positions of Spencer and Bergson are unfortunately too briefly set forth to be of much aid to those not already