Decembee 23, 1921] 



SCIENCE 



631 



port the observatory, which has since been 

 done. The observatory now receives by law 

 the income of a tax levy of one twentieth of 

 a mill. 



IsTevin M. Fenneman 

 XJniversitt op Cincinnati, 

 December 2, 1921 



SCIENTIFIC BOOKS 



THE ORDER OF NATURE 



The Principles of Natural Knowledge, by 

 A. N. Whitehead, Cambridge University 

 Press, 1919. 

 L'Unite de la Science, by Leclerc du Sablon. 



Felix Alcan, Paris, 1919. 

 The Order of Nature, by Lawrence J. Hen- 

 derson. Harvard University Press, 1917. 

 The System of Animate Nature, by J. A. 

 Thomson. Two volumes. Williams and 

 Norgate, London, 1920. 

 In the first dialogue between Hylas and 

 Philonous Berkeley has the latter to say : " I 

 am not for imposing any sense on your 

 words: you are at liberty to explain them as 

 you please. Only, I beseech you, make me 

 understand something by them." The author 

 of " The Principles of ISTatural Knowledge " 

 has obviously had before him not only this de- 

 mand, which he sets forth by giving the fore- 

 going quotation on his title-page, but also the 

 further one that every intelligent reader shall 

 understand the same things by his words. 

 Neither of these ideals is easily realized in 

 philosophical writings; and this is most em- 

 phatically true of those which are addressed 

 to readers not interested in the technical 

 aspects of philosophy. Why does this diffi- 

 culty exist? "We have to remember that 

 while nature is complex with timeless sub- 

 tlety, human thought issues from the simple- 

 mindedness of beings whose active life is less 

 than half a century." 



The author seeks to realize clarity by the 

 so-called " method of logical atomism " 

 which " has gradually crept into philosophy 

 through the critical scrutiny of mathemat- 

 ics " and in his discussion to substitute 

 " piecemeal, detailed and verifiable results for 

 large untested generalities recommended only 



by a certain appeal to the imagination," to 

 use Bertrand Russell's characterization of the 

 philosophy of logical atomism. Whitehead 

 analyzes thought into elements which the un- 

 sophisticated mind could never recognize as 

 parts of its original thought content; and 

 sometimes even for the expert, one must be- 

 lieve, there is real difficulty in putting to- 

 gether the parts so as to recover the whole. 

 But the reader is not in doubt as to what 

 the author says or what he means. White- 

 head says: 



" The fundamental assumption to be elab- 

 orated in the course of this enquiry, is that 

 the ultimate facts of nature, in terms of 

 which all physical and biological explanation 

 must be expressed, are events connected by 

 their spatio-temporal relations, and that 

 these relations are in the main reducible to 

 the property of events that they contain (or 

 extend over) other events which are parts of 

 them." Time is not a succession of instants, 

 but a complex of interlocking events, each 

 helping to tie the others to the past and the 

 future. " The conception of the instant of 

 time as an ultimate entity is the source of all 

 our difficulties of explanation. . . . Our 

 perception of time is as a duration." 



The work as a whole contains a somewhat 

 technical and rather disjointed analysis of 

 four matters, namely: the traditions of 

 science; the data of science; the method of 

 extensive abstraction; the theory of objects. 

 The book will have its greatest appeal to the 

 reader of considerable mathematical matu- 

 rity, even though it does not at all depend 

 on mathematical detail ; for the point of view 

 is evidently taken in the light of the recent 

 philosophy of mathematics. 



In " L'Unite de la Science " by M. Leclerc 

 du Sablon we have an equal clarity, but it 

 difiers from that of Whitehead's work in be- 

 ing strongly marked by French character- 

 istics. 



In his preface Whitehead says : " In matters 

 philosophic the obligations of an author to 

 others usually arise from schools of debate 

 rather than from schools of agreement. Also 

 such schools are the more important in pro- 



