PREFACE. 



OF the two divisions contained in this volume, the first 

 has already appeared in print in the shape of review-articles ; 

 but the second is new. With the publication of them in a 

 united form, the issue of the Synthetic Philosophy comes to 

 a close. 



The series of works included under that title is complete 

 and yet incomplete. There were to be ten volumes, and 

 there are ten. According to the programme, besides a 

 volume of First Principles, there were to be two volumes of 

 Biology ) two of Psychology, three of Sociology, and two of 

 Ethics / and to each of these subjects the specified number 

 of volumes has been appropriated. Still in one respect there 

 is a falling short. The interpretation of the paradox is that 

 the first two volumes of The Principles of Sociology have 

 expanded into three, and the third (which, if written, would 

 now be the fourth) remains unwritten. It was to have 

 treated of Progress Linguistic, Intellectual, Moral, ^Es 

 thetic. But obviously for an invalid of seventy-six to deal 

 adequately with topics so extensive and complex, is impos 

 sible. 



It must, however, be pointed out that while this portion of 

 the original project remains unexecuted, considerable por 

 tions not projected, have been added. In The Principles of 

 Psychology, the division &quot; Congruities,&quot; and in The Princi 

 ples of Sociology, the division &quot; Domestic Institutions,&quot; are 

 in excess of the divisions promised; and there have been 

 joined with sundry of the volumes, various appendices, mak 

 ing altogether 430 pages extra. Something even now re 

 mains. Though not within the lines of the scheme as at first 



