XXVI INTRODUCTION. 



properly belongs, have also attempted to give expositions 

 of scientific faith and doctrine. Within the past forty 

 years Comte, Mill, Strauss, and -Herbert Spencer have all 

 essayed it. But as the two former wrote before the 

 discovery of the two most comprehensive generalizations 

 iu physics and biology the law of the Conservation of 

 Energy and the law of Natural Selection they failed to 

 reach the new and more commanding point of view 

 which these two laws place henceforth at the disposal of 

 thinkers. Their systems are accordingly to a consider- 

 able extent superseded as incomplete scientific explana- 

 tions of the universe, while the moral and social doctrines 

 of both are pronounced by Herbert Spencer inconsistent 

 with the deepest and widest generalizations of the laws 

 of life and society. 



Herbert Spencer has himself, in the various volumes 

 of his new system of evolution-philosophy, given the 

 most complete and philosophic statement of the scientific 

 faith, and he has given it with special references to the 

 above-named highest laws. But waiving the fact that 

 physicists object to some of his physics, and philosophers 

 to some of his philosophy, the system is itself so volu- 

 minous and vast in fact, so severe a course of reading, 

 which postulates a special facility in the art of quickly 

 apprehending the meaning of a train of abstract symbols, 

 scientific and philosophic that a more compendious if 

 not an easier exposition would seem a matter to be 

 desired. To supply some such condensed exposition to 

 the large and increasing class who have an intelligent 

 human interest in the new scientific theories, and in the 

 great collision and controversy now going on between 

 the new and old beliefs is one object of this book ; to 

 supplement the exposition with a criticism which may 

 assist them to separate the false from the true elements 



