SCIENTIFIC LITERATURE. 559 



that too great uniformity proves injurious. Much attention is bestowed 

 upon the hypnagogic condition or state of half-awakening; connection is 

 found between this and some states of mental aberration, and it always de- 

 notes a weakened consciousness. 



The point of view taken in examining the psychic life of sleep is that 

 " the subjective method is of the first importance." Another divergence 

 from scientific habit of thought is that " in attempting to explain facts by 

 chemical affinity we still have to explain chemical affinity itself." Obser- 

 vations made by the author during five years on thirty-seven persons con- 

 vince her that dreams increase with the variety and activity of intellectual 

 life. The studies of an Italian investigator show that idiots rarely dream, 

 criminals dream seldom and but little, the greatest criminals least of all. 

 Whence she concludes that it is only under morbid conditions and among 

 the uneducated that it is common to find an absence of dreams. Not only 

 are the dreamless thus condemned to a low intellectual plane, but " old age 

 comes on more swiftly in those who dream little." 



Prof. J. Mark Baldivirts Social and Ethical Interpretations in Mental 

 Development * is a continuation of the studies in genetic psychology 

 begun in the Mental Development of the Child and the Race. It is, how- 

 ever, independent of that work except in so far as the natural connection 

 requires somewhat frequent reference to it. In view of the lack in English 

 of a book on social psychology which can be used in the universities in 

 connection with courses in psychology, ethics, and social science, the 

 author has also endeavored to make his essay available for that purpose. 

 This has led to such expausion of the fundamental ideas of the treatise as 

 seemed necessary to a fairly complete working out of the social element in 

 connection with each of the great psychological functions. The first part 

 is, therefore, as far as its topics are concerned, a more or less complete study 

 of social and ethical philosophy. The special object of the essay is to in- 

 quire to what extent the principles of the development of the individual 

 mind apply also to the evolution of society. The study, therefore, falls into 

 two main inquiries : What are the principles which the individual shows in 

 his mental life — principles of organization, growth, and conduct; and what 

 additional principles, if any, does society exhibit in its forms of organiza- 

 tion, progress, and activity ? Of the three methods by which the author 

 conceives the subject may be investigated, he chooses what he calls the 

 genetic, or that " which inquires into the psychological development of 

 the individual in the earlier ages of his growth for light upon his social 

 nature, and also upon the social organization in which he bears a part." 

 The evidence is drawn largely from actual observation of children, and 

 the main thought is the conception of the child's sense of personality. 

 This is developed in Book I, which presents the person in public and 

 private, as imitative, self-conscious, social, and inventive; his equipment, 

 with instincts, emotions, intelligence, and sentiments; and his personal 

 and social sanctions. The second book relates to society — the person in 

 active and social organization — the social forces, social matter and pro- 

 cess, and social progress. From the whole are deduced practical con- 

 clusions and rules of conduct. Some of the chapters in the second book 



* Social and Ethical Interpretations in Mental Development. A Study in Social Psychology. By 

 James Mark Baldwin. New York : The Macmillan Company. Pp. 574. Price, §2.60. 



