2 $8 THE FOUNDATIONS OF ZOOLOGY 



or important to the sand; and yet see clearly that skill in catching 

 mice is useful to cats, even if the mouse might also have some- 

 thing to say on the subject if he could be heard. 



As I understand "the old argument from design as given by 

 Paley," it is as follows: 



(1) Nothing accounts for watches but mind. 



(2) Nothing accounts for living things unless it accounts for 

 watches. 



(3) Nothing but mind accounts for living things. 



The resemblance between the watch and the eye is no less real 

 and no less obvious than it was before natural selection was dis- 

 covered ; and this discovery seems to me so far from destroying 

 Paley's minor premise that it gives to human contrivances a sig- 

 nificance of which Paley never dreamed ; for it shows that the 

 basis for his argument, which he finds in the resemblance between 

 human contrivances and the attributes of living things, is impreg- 

 nable. 



If it be true that natural selection has given a death-blow to 

 his argument, Darwin and Huxley and Romanes fail, in the pas- 

 sages I have quoted, to show either the nature of the blow or 

 how it hits the argument; for no one can see the whole meaning 

 of natural selection without seeing that we no longer have any 

 reason to think that the history of watches differs in any funda- 

 mental way from the history of spiders' webs, and birds' nests, 

 and eyes, and cats. 



As the mind refuses to believe that the relation between cats 

 and mice is due to "chance," the difficulty pre-Darwinian thinkers 

 found in accounting for it, without attributing it to interference 

 with the course of nature, was inability to find, in our knowledge 

 of nature, any reason why the life of mice should ever be brought, 

 in course of nature, into that peculiar relation to the structure 

 of cats which we call physical causation. 



Wallace and Darwin have shown that this causal relation 

 actually exists, and that the life of mice is an important element 

 in that objective or physical environment of cats which has deter- 

 mined all that is distinctive or characteristic in their structure by 

 extermination and survival. While it may be no explanation of 



