PREFACE. 9 



its most extended sense. Yet it appeared convenient to car 

 ry on the history of Science, so far as it depends on Observa- 

 tion, in a line separate from these discussions concerning 

 Ideas. The account of these discussions and the consequent 

 controversies, therefore, though it be thoroughly historical, 

 and, as appears to me, a very curious and interesting history, 

 is reserved for the other work, the Philosophy of the Induc- 

 tive Sciences. Such a history has, in truth, its natural place 

 in the Philosophy of Science ; for the Philosophy of Science 

 at the present day must contain the result and summing up 

 of all the truth which has been disentangled from error and 

 confusion during these past controversies. 



I have made a few Additions to the present Edition ; 

 partly, with a view of bringing up the history, at least of 

 some of the Sciences, to the present time, so far as those 

 larger features of the History of Science are concerned, with 

 which alone I have here to deal, and partly also, especially 

 in the First Volume, in order to rectify and enlarge some of 

 the earlier portions of the history. Several works which 

 have recently appeared suggested reconsideration of various 

 points'; and I hoped that my readers might be interested in 

 the reflections so suggested. 



I will add a few sentences from the Preface to the First 

 Edition. 



" As will easily be supposed, I have borrowed largely 

 from other writers, both of the histories of special sciences 

 and of philosophy in general. 1 I have done this without 



1 Among these, I may mention as works to which I have peculiar obligations, 

 Tennemann's Geschichte der Philosophic ; Degperando's Histoire Comparee des Sys- 

 temes de Philosophic ; Montucla's Histoire des Mathematiques, with Delalande's 

 continuation of it; Delambre's Astronomie Ancienne, Astronomic clu Moyen A<re, 

 Astronomic Moderne, and Astronomie du Dix-huitieme Siecle ; Bailly's Histoire 

 d' Astronomic Ancienne, and Histoire d' Astronomie Moderne; Voiron's JIi-:i;J- 



