SPENCER AND EVOLUTION. 27 



idea of that essay was reached. This idea, that the forms of organisms, 

 in respect of the different kinds of their symmetry and asymmetry, are 

 caused by their different relations to surrounding incident forces, im- 

 plies a general recognition of the doctrine of Evolution, a further ex- 

 tension of the doctrine of adaptation, and a foreshadowing of the theory 

 of life as a correspondence between inner and outer actions. 



In 1852 Mr. Spencer published in the Westminster Review the 

 "Theory of Population deduced from the General Law of Animal 

 Fertility," setting forth an important principle which he says that he 

 had entertained as far back as 1847. Here also the general belief in 

 Evolution was tacitly expressed ; the theory being that, in proportion 

 as the power of maintaining individual life is small, the power of mul- 

 tiplication is great ; that along with increased evolution of the indi- 

 vidual there goes decreased power of reproduction ; that the one change 

 is the cause of the other ; that in man as in all other creatures the ad- 

 vance toward a higher type will be accompanied by a decrease of fer- 

 tility ; and that there will be eventually reached an approximate equi- 

 librium between the rate of mortality and the rate of multiplication. 

 Toward the close of this argument there is a clear recognition of the 

 important fact that excessive multiplication and the consequent strug- 

 gle for existence cause this advance to a higher type. It is there 

 argued that " only those who do advance under it eventually survive" 

 and that these " must be the select of their generation." That which, 

 as he subsequently stated in the " Principles of Biology," Mr. Spencer 

 failed to recognize at this time (1852) was the effect of these influences 

 in producing the diversities of living forms ; that is, he did not then 

 perceive the cooperation of these actions of the struggle for existence 

 and the survival of the fittest with the tendency to variation which 

 organisms exhibit. He saw only the power of these processes to pro- 

 duce a higher form of the same type, and did not recognize how they 

 may give rise to divergencies and consequent differentiations of species, 

 and eventually of genera, orders, and classes. 



Early in 1852, Mr. Spencer also printed a brief essay in the Leader, 

 on "The Development Hypothesis," in which some of the now cur- 

 rent reasons for believing in the gradual evolution of all organisms, in- 

 cluding man, are indicated. To this paper Mr. Darwin refers in the 

 introductory sketch of the previous course of research on the subject 

 of development, which he prefixed to the " Origin of Species." In 

 this essay, however, direct adaptation to the conditions of existence is 

 the only process recognized. 



In October of the same year (1852), Mr. Spencer published an 

 essay in the Westminster Review, on the "Philosophy of Style," in 

 which, though the subject appears so remote, there are traceable some 

 of the cardinal ideas now indicated, and others that were afterward 

 developed. The subject was treated from a dynamical point of view, 

 and, as Mr. Lewes remarks in his essays on the " Principles of Success 



