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THi: POPULAR SCIENCE MONTHLY. 



blest motives, both for self-discipline and 

 for philanthropic exertion, is unworthy of 

 the nature and destiny of the being whose 

 creation in the ' image of God ' can have 

 no higher meaning than his capacity for 

 infinite progress^ 



The difference between the new point of 

 view and the old is not a mere speculative 

 difference, or a matter of abstract belief. 

 The study of man as an actual whole, a 

 complex working phenomenon, and a fact 

 of experience, has given us a kind of knowl- 

 edge that is invaluable for the uses of all in 

 every-day life. This kind of knowledge, 

 concerning human nature, has been long 

 and slowly accumulating, as the result of 

 modern observation, though it has recently 

 become more extended and accurate in 

 many particulars, and Dr. Carpenter's work, 

 we may say, has first presented it with the 

 systematic fullness which its importance de- 

 mands. 



In his plan of treatment. Dr. Carpenter 

 classifies from the mental side ; that is, it 

 is mental phenomena and problems that 

 are successively taken up. After a prelim- 

 inary statement of the general relations be- 

 tween mind and body, in the first chapter, 

 he takes up the structure and modes of ac- 

 tion of the nervous apparatus in the second 

 chapter, and then proceeds to consider in 

 successive chapters the subjects of Atten- 

 tion, Sensation, Perception, and Instinct, the 

 Emotions, the Will, Memory, Common-sense, 

 Unconscious Cerebration, Reverie, Sleep, 

 Dreaming, Somnambulism, Electro-biology, 

 Mesmerism, and Spiritualism,- Intoxication 

 and Delirium. But each and all of these 

 manifestations are considered, not in them- 

 selves merely, but as conditioned by the 

 physiological constitution. Whatever may 

 be their ultimate nature, practically they 

 are effects of a vital mechanism by the laws 

 of which they are determined. Much of 

 this wonderful connection is of course, as 

 yet, far from being understood. We are 

 indebted to Dr. Carpenter for having shown 

 that a great deal more is understood of the 

 psychical and vital interactions than has 

 become generally known. Dr. Carpenter 

 has won his reputation as a physiologist, 

 largely from the clearness of his exposi- 

 tions, and the present work shows that his 

 capacity in this respect is still vigorous. 



Its most scientific parts are attractive read- 

 ing, and the extensive array of personal in- 

 stances and incidents, which illustrate his 

 positions, gives great fascination to the vol- 

 ume. It is a book hard to lay down when 

 once entered upon, and Dr. Carpenter may 

 be congratulated upon having contributed 

 so fresh and adequate a book upon such an 

 important subject. 



The Principles of Science. A Treatise on 

 Logic and Scientific Method. By W. 

 Stanley Jevons, M*. A., F. R. S., Fellow 

 of University College, London ; Professor 

 of Logic and Political Economy in the 

 Owens College, Manchester. New York ; 

 Macmillan &, Co. 2 vols., 948 pages. 

 Price, $9. 



This able treatise is entitled to be classed 

 at once with such valuable and solid works 

 as Mill's " Logic," Whewell's " History of 

 the Inductive Sciences," and Herbert Spen- 

 cer's "First Principles." Whether it be 

 equal to either of those treatises, as a con- 

 tribution to scientific knowledge, we shall 

 not assume to say, but it is certainly a time- 

 ly and powerful exposition of scientific 

 method, in the light of the later advances 

 of knowledge. The author sets out with 

 the assumption, which few will question, 

 that the rapid progress of the physical sci- 

 ences during the last three centuries has 

 not been accompanied by a corresponding 

 advance in the theory of reasoning. Physi- 

 cists are usually too much engrossed in the 

 immense and ever-accumulating details of 

 their special sciences to give sufficient at- 

 tention to the methods of reasoning which 

 they unconsciously employ. It becomes 

 necessary, then, that certain minds should 

 devote themselves absorbingly to this neg- 

 lected side of science, for few will deny that 

 the clearing up of questions of order, logic, 

 and method, are indispensable to its ration- 

 al progress. To do any justice to this work, 

 by a notice or review of it within such space 

 as we can allow, would be impossible, and 

 the best course is to let the author speak for 

 himself in regard to the aims and character- 

 istics of his undertaking. The following 

 passages are from his preface : 



" The study both of Formal Logic and 

 of the Theory of Probabilities has led me 

 to adopt the opinion that there is no such 

 thins as a distinct method of induction as 



