338 AIM AND PROGRESS OF PHYSICAL SCIENCE. 



might feel disposed to ascribe to it a higher rather than a lower 

 character. 



Before the time of Darwin only two theories respecting 

 organic adaptability were in vogue, both of which pointed to 

 the interference of free intelligence in the course of natural pro- 

 cesses. On the one hand it was held, in accordance with the 

 vitalistic theory, that the vital processes were continuously di- 

 rected by a living soul ; and, on the other, recourse was had to an 

 act of supernatural intelligence to account for the origin of every 

 living species. The latter view indeed supposes that the causal 

 connection of natural phenomena had been broken less often, 

 and allows of a strict scientific examination of the processes 

 observable in the species of human beings now existing ; but 

 even it is not able to entirely explain away those exceptions to 

 the law of causality, and consequently it enjoyed no considerable 

 favour as opposed to the vitalistic view, which was powerfully 

 supported, by apparent evidence, that is, by the natural desire 

 to find similar causes behind similar phenomena. 



Darwin's theory contains an essentially new creative thought. 

 It shows how adaptability of structure in organisms can re- 

 sult from a blind rule of a law of nature without any interven- 

 tion of intelligence. I allude to the law of transmission of 

 individual peculiarities from parent to offspring, a law long 

 known and recognised, and only needing a more precise defi- 

 nition. If both parents have individual peculiarities in com- 

 mon, the majority of their offspring also possess them : and if 

 among the offspring there are some which present these peculiar- 

 ities in a less marked degree, there will, on the other hand, 

 always be found among a great number, others in which the 

 same peculiarities have become intensified. If, now, these be 

 selected to propagate offspring, a greater and greater intensifica- 

 tion of these peculiarities may be attained and transmitted. 

 This is, in fact, the method employed in cattle-breeding and 

 gardening, in order with greater certainty to obtain new breeds 

 and varieties, with well-marked different characters. The ex- 

 perience of artificial breeding is to be regarded, from a scientific 

 point of view, as an experimental confirmation of the law under 



