NA TURE 



THURSDAY, FEBRUARY i, rgo6. 



A 



THE PHILOSOPHIC FOUNDATIONS OF 

 SCIENCE. 

 Science and Hypothesis. By Prof. H. Poincare. 

 Pp. xxvii+244. (London: The Walter Scott Pub- 

 lishing Co., 1905.) Price 3s. 6d. 

 Wissenschaft und Hypothese. By Prof. H. Poincare. 

 Autorisierte deutsche Ausgabe. Translated by 

 F. and L. Lindemann. Pp. xvi + 342. (Leipzig: 

 Teubner, 1904.) Price 4.80 marks. 



SCIENTIFIC man, while actively engaged in 

 work of research, must have faith in the solidity 

 of the foundations on which he builds his reasoning 

 in order to preserve the persistent patience which is 

 necessary if his work is to be successful. Wen- he 

 to doubt that there are laws which cannot be broken, 

 were he to examine critically every brick in his founda- 

 tion in order to discover some secret flaw which might 

 endanger the safety of his edifice, he would become 

 a philosopher, but as a man of science he would go 

 to swell the ranks of the unemployed. Nevertheless, 

 we must assign a proper place in the history of 

 scientific thought to the spirit of scepticism which 

 throws doubt on the premises, has no faith in the 

 reasoning, and onlv grudgingly concedes the con- 

 clusions. If I have qualified the statement contained 

 in the opening sentence and confined its application 

 to the time a man is actively engaged in scientific 

 work, it is because there are periods in every man's 

 life when it is good for him to dig down to the bottom 

 of his beliefs. Nor will the critical examination of 

 axioms and definitions be without profit; for it will 

 tend to loosen the ties of preconceived notions which 

 keep men of science, like other mortals, in bondage. 



The special difticultv of inquiring into the laws 

 which form the basis of our scientific beliefs consists 

 in the fact that it is apt to lead us round in a circle. 

 When we have tried to formulate a law of nature, we 

 often discover that we have only defined a scientific 

 term. A superficial mind, satisfied with this dis- 

 covery, would proclaim that all science resolves itself 

 into definitions and conventions, but a closer examin- 

 ation exposes the shallowness of such a conclusion. 



lusn 



If among a number of possible definitions we choose 

 a particular one, there must be a deeper meaning in 

 the propriety of the choice. Even though a law may 

 be of our own making, to use Prof. Poincare's de- 

 scriptive language, " our decrees are those of an 

 absolute but wise ruler who consults his Council of 

 State." The inquiry into a law of nature resolves 

 itself, therefore, into an inquiry why that particular 

 law is more convenient than others that can be 

 imagined, but this conclusion only brings us back 

 to our starting point, the question as to the truth of 

 a law and its convenience being identical. 



Prof. Poincare's volume will come as a revelation 

 to many who have thought but little about these 

 matters, and as a relief to others who have attempted 

 without success to arrive unaided at a conclusion 

 satisfactory to themselves. But the book requires 

 no. 1892, VOL. yT,~\ 



close and careful study, and a superficial gleaning 

 of its contents would probably lead to mental disaster. 

 For, even following Prof. Poincare's guidance, we feel 

 ourselves all the time walking along a precipice, at 

 the bottom of which is written, " You shall never 

 know anything of the real construction of the material 

 universe." The author seems to enjoy taking us very 

 near the edge of that pit, and when he whispers into 

 our ears, " what you cannot know is not worth 

 knowing," we feel as if he intended to throw us over. 

 But he has a sense of humour which saves him and 

 us, and there is always a solution which we should 

 perhaps have rejected at first sight, but which we 

 are glad to accept alter a contemplation of the less 

 cheerful alternatives which have been brought into 

 our view. There is certainly no one with the same 

 intimate knowledge of mathematical and physical 

 science who could have written with the same 

 authority and produced a volume in which so much 

 charm and originality are condensed. The wealth of 

 his store of illustration is boundless, and the stringency 

 of his logic leaves us without answer. Even in cases 

 when our instincts rebel, we are carried away by the 

 fascination of the language, which in each subdivision 

 of the subject takes us with dramatic power to ii- 

 artistic denouement. 



Could and should such a book be translated? The 

 fascination of the original can certainly never be 

 reached, but translation is allowable where the main 

 argument can be reproduced without loss ol clearness, 

 though the delicacies of meaning to which the French 

 language peculiarly adapts itself will undoubtedly be 

 lost. 



The English translation errs, perhaps, on the side 

 of following too literally every .sentence, and some- 

 times even everv word in the sentences, of the French 

 original. The meaning of the text is carefully though 

 often awkwardly preserved. While the reader is not 

 carried away by the incisive character of expression 

 which belongs to the original, he will in most cases 

 be able to re-construct the dominant idea. The 

 German translation is more successful. We must 

 ascribe this in the first place to the fact that one ol 

 the translators has himself made important contri- 

 butions to certain parts of the subject, and, feeling 

 himself secure in apprehending the meaning, has 

 been able to reproduce the sense without putting any 

 strain on the language. The result is that, while no 

 one could read a few pages of the English edition 

 without recognising the fact that it is a translation, 

 the German carries with it much more of the freshness 

 of an original book. The German translator is also 

 to be commended for the addition ol a good index. A 

 series of notes is added, which take up a considerable- 

 fraction of the whole volume. Many of these notes wilt 

 be useful, as they supply references to writings where 

 the readers can study in greater detail important 

 points on which Prof. Poincare only touches with a 

 passing allusion. But I cannot refrain from criticis 

 ing the introduction of controversial matter. Differ 

 ences of opinion between Sophus Lie and Prof. 

 Lindeman are surely out of place in the translation 

 of a book of this nature. 



