CONTENTS 



AUTOBIOGRAPHY 1 



I 



ON THE ADVISABLENE8S OF IMPROVING NATURAL KNOW- 

 LEDGE 18 



(Lay Sermon, St. Martin's Hall, Sunday 

 Evening, January 7th, 1866). 



II 



THE PROGRESS OF SCIENCE [1887] 42 



III 



|j ON THE PHYSICAL BASIS OF LIFE 130 *r 



(Lay Sermon, Edinburgh, Sunday Evening, 

 November 8, 1868). 



IV 



ON DESCARTES' "DISCOURSE TOUCHING THE METHOD OF 

 USING ONE'S REASON RIGHTLY AND OF SEEKING 

 SCIENTIFIC TRUTH " 166 



(Address, Cambridge Young Men's Christian 

 Society, March 24, 1870). 



