PREFACE. vii 



matics, and the recondite methods of modern analysis. It 

 may here be proper to observe that as a science advances to 

 perfection it is more and more concerned with processes of 

 mathematical deductions. There are some sciences which 

 have long consisted chiefly of deductions made from a few 

 simple principles established by experience once for all. Such 

 are mechanics, hydrostatics, parts of optics and of astronomy. 

 The abstract mathematical forms of such parts of science make 

 them less generally attractive, and where in the following pages 

 these sciences are entered upon under the designation of 

 "The Mathematical Sciences," it is usually some of the experi- 

 mental or inductive particulars that are discussed. 



The plan upon which the subject matter has been arranged 

 is to give the first three chapters to ancient science, divided 

 mainly into ancient Greek, Alexandrian Greek, Arabian, and 

 Mediaeval schools. A chapter is then apportioned to the science 

 of the sixteenth century generally, while for each succeeding 

 century separate chapters are assigned to the several sciences 

 or groups of sciences. Three chapters, specially devoted to the 

 respective labours of the epoch-forming men, Galileo, Bacon, 

 and Newton, take their places among the rest and carry on the 

 narration. The division of the matter according to centuries 

 has of course no intrinsic significance, being adopted merely 

 for convenience of reference ; and the classification of the 

 sciences into mathematical sciences, natural history sciences, 

 etc., suggested by the titles given to some of the chapters, is to 

 a great extent also arbitrary. Two more remarks we have to 

 make for the reader's avoidance of misconceptions. He must 

 not assume that the subjects which he finds touched upon in 

 the following pages under the name of each philosopher neces- 

 sarily represent the whole of that philosopher's useful scientific 

 activity. Still less will he be entitled to suppose that the 

 names of the few living men of science which happen to find 

 a place in this volume are introduced by reason of the pre- 

 eminence of their owners above the rest of the many distin- 

 guished cultivators of science, whose splendid labours also are 



