PREFACE 



SINCE the appearance in 1909 of our book on The 

 Family and the Nation, we have published occasional 

 papers and articles extending some of the ideas therein 

 contained. Although the present volume reproduces the 

 substance of some of these papers, the larger portion of 

 it consists of hitherto unprinted work. To prevent the 

 need of reference to the former book, certain sections 

 have been abstracted and re-written, such as the one 

 on the scientific aspect of Variation, and the statistical 

 portion of the chapter on the Birth-rate ; but any 

 one who desires to study these and kindred subjects in 

 more detail must consult the earlier volume, especially 

 the chapters on Inheritance and Variation in Mankind, 

 the Inheritance of Mental Defect and Ability, and the 

 Selective Birth-rate. The causes of the decline in the 

 birth-rate are there likewise discussed. 



We wish especially to guard against one miscon- 

 ception into which certain of our former readers and 

 reviewers seem to have fallen. Both this book and its 

 predecessor are written avowedly to draw attention 

 to the problem of heredity, a conception which has 

 hardly yet penetrated consciously into modern sociology, 

 where the subject of environment has held hitherto 

 almost limitless sway. We find it necessary continually 

 to point out that improved conditions of life will not 



