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THE POPULAR SCIENCE MONTHLY. 



reader. The book is, therefore, written as 

 much as possible from an unprofessional 

 point of view, and in a way to require no 

 previous technical training. Although any 

 treatment of fallacies must, to a great ex- 

 tent, deal with methods of proof, and must, 

 therefore, demand a certain amount of gen- 

 eral logical theory, yet by trying to keep 

 chiefly in view the practical and applicable 

 side of the science of logic, and subordi- 

 nating all else to this, Professor Sidgwick 

 claims to have been able to neglect the dis- 

 cussion of much debatable matter, and to 

 avoid definite adherence to a school. Mill 

 and Bain are chiefly followed, but the author 

 has attempted to utilize their most impor- 

 tant results without being compelled to ac- 

 cept the whole of their philosophy. The fol- 

 lowing passages from Professor Sidgwick's 

 introductory chapter may serve to illustrate 

 the point of view from which he regards 

 his subject, and also his fresh and uncon- 

 ventional manner of writing upon it : 



Logic holds what may well be called an uncom- 

 fortable position among the sciences. According to 

 some authorities, it can not be properly said that a 

 body of accepted logical doctrines exists ; according 

 to others, the facts and laws that form such doc- 

 trine are so completely undeniable, that to state 

 them is hardly to convey new or important infor- 

 mation. Ilence, if a writer on the science tries to 

 avoid truism, and so to give practical importance 

 to his statements, there is danger both of real but 

 crude innovation, and also of over-simple belief in 

 the value of merely verbal alterations. Moreover, 

 at its best, logic has many persistent enemies, and 

 by no means all of them are in the wrong ; so that 

 those who view the science as the thief or burglar 

 views the law, find themselves apparently supported 

 and kept in countenance by others who reaily have 

 the right to view it as perhaps the artist views tho 

 rules that hamper genius. Through its deep con- 

 nection with common sense, logic is often a source 

 of exasperation to philosophy proper ; while com- 

 mon sense, on the other hand, is apt to dread or dis- 

 like it as unpractical or over-fond of casuistical re- 

 finements. Failing thus to win a steady footing, it 

 turns, sometimes, to physical science for a field of 

 operations ; but physical science has its proper 

 6hare of boldness, and often leaves the cautious 

 reasoner behind. As for art which finds even com- 

 mon sense too rigid here logic is liable to meet 

 with opposition at every grade ; from the righteous 

 inpatience of poetic souls that are genuinely under 

 grace, down to the incoherent anger of mere boast- 

 ful vagueness, or to the outcry of the sentimental 

 idler. 



In the midst of these perplexities, it is difficult 

 to choose a quite satisfactory course. Some excuses 

 may, however, be offered for the line that has here 

 been taken ; and, first, I would plead, as against the 



charge of irregularity or presumption, the fact that 

 I have wished to keep a single purpose in view, 

 avoiding all questions that fail to bear directly upon 

 it. Usually in works on logic, the object has been 

 to say something valuable upon all the questions 

 traditionally treated as within the field of the sci- 

 ence, and, in attempting this, the single, practical 

 purpose is apt to become obscured. It is only in 

 consequence of my avoidance of side-issues that 

 any appearance of novelty in the treatment has fol- 

 lowed. Moreover, it is not teaching, but suggestion 

 that is chiefly here intended. It is always allow- 

 able to write rather in the co-operative spirit than 

 the didactic, and this has certainly been my aim 

 throughout. And the same apology may apply to 

 the charge of forcing verbal changes upon the read- 

 er ; the novelties of statement are here put forward 

 merely as possible aids in keeping our single pur- 

 pose clear, and, in fact, I found them almost un- 

 avoidable. 



As regards physical science, it must be confessed 

 that logic merely follows after it, systematizing 

 methods already adopted there, and found to lead 

 to good results. And I hold that to combat fallacy 

 is the raison d'etre of logic; and that science, 

 though not infallible, is more free from discover- 

 able fallacies than any other field of thought. 

 Again, while experimental methods may no doubt 

 be capable of much improvement, it seems a ten- 

 able view that the duty should be left to a special 

 and very advanced department of inquiry. There 

 might, perhaps, be formulated a system of advice 

 for discovery in general rules and hints important 

 even to the leading men of science. But, in the 

 mean time, logic (as usually understood) can hardly 

 help containing a good deal of elementary matter, 

 and is compelled to take for granted in the learner 

 a power of making very elementary mistakes. It 

 seems that the best scientific discovery must always 

 be in advance of inductive logic, in much the same 

 way as the best employment of language runs in 

 advance of grammar. Still, there may be some use 

 in trying to direct and help those who are not al- 

 ready scientific, or only in the earlier stages of tho 

 pursuit ; nor need the name [of logic compel logi- 

 cians to claim a dignity beyond their power. One 

 can not fulfill successfully the duties of lord chan- 

 cellor and justice of the peace at once. 



A Natural History Reader. For School 

 and Ilome. Compiled and arranged by 

 James Johonnot, author of " Principles 

 and Practice of Teaching," etc. New 

 York: Pp. 414. D. Appleton & Co. 

 Price, $1.25. 



The work of the compiler of this vol- 

 ume has been executed with intelligence, 

 taste, and good practical judgment, and he 

 has made of it a most interesting book of 

 natural history for general reading. It is 

 an excellent sign of the healthy growth of 

 an interest in science when works of this 

 kind are called for and introduced into 

 schools. The literature of science must 



