Bill 



PREFACE. 



IT is difficult to picture the succession of events that compose 

 the history of a nation in any other way than by associating them 

 with the fortunes of individuals. Hence the common complaint 

 that, instead of the histories of peoples, we have only the lives of 

 kings and military leaders. Historians find that this is the 

 readiest way to connect the events, and render them easily 

 remembered. 



The same expedient is, perhaps, still more necessary in tracing 

 the progress of human opinions. The history of thoughts is best 

 understood and remembered in connection with the history of 

 the thinkers. Those ' airy nothings' can hardly become fixed ob- 

 jects in the memory, but by giving them ' a local habitation and 

 a name ;' and a necessary commentary on the writings or doc- 

 trines of a philosopher, is a knowledge of the character and 

 environment of the man. 



It is on this principle that, in the present volume, the History 

 of ancient Philosophy and Science is associated with Biographical 

 notices of the leading thinkers and writers. As it is hardly 

 to be supposed that one man should be equally conversant with 

 all the parts of so extensive a subject, the several sketches that 

 compose the volume have been contributed by different hands. 

 Owing to this, and to the circumstance that they stood originally 

 in a different connection, they unavoidably involve some degree 



