52 THE FOUNDATIONS OF ZOOLOGY 



in a steam-engine. If absence of disproof were proof, they who 

 assert that, so far as complexity is in question, the difference be- 

 tween the actions of a stone and those of a dog is merely a differ- 

 ence of degree, not of kind, may have some ground for their 

 belief, inasmuch as no one can say it may not some day be 

 demonstrated. I, for one, see no other reason, than that no 

 one knows, for doubt whether sufficient knowledge might not 

 enable us to foresee or deduce the actions of the dog from the 

 structure of his body ; but we have not yet noted the most essen- 

 tial characteristic of his actions. They are significant. They 

 have a meaning. They stand in judicious adjustment to the 

 canine world ; and their meaning can never, so far as I can see, 

 be learned by studying his body ; for if the meaning which our 

 minds apprehend is embodied in any structure, it must be in our 

 own, rather than in that of the dog. It may be that all that 

 makes up the dog's external world is imprinted in his organiza- 

 tion, and that the naturalist of some distant age may be able to 

 there exhibit it, just as the photographer brings out the picture 

 on his negative ; but even if this were done, the picture would 

 still remain only an image of an external world which, while more 

 limited, is otherwise practically the same as our own. However 

 this may be, the only way to study the meaning of the dog's 

 actions, at the present day, is to seek it in his environment; in 

 the conditions under which he and his ancestors have lived; nor, 

 in order to study this meaning, need one know whether the dog 

 is aware of it. 



While there seems to be good ground for reasonable confi- 

 dence that the dog is conscious and rational, we know nothing 

 whatever concerning the presence or absence of consciousness in 

 most living things, although we do know that their actions are 

 beneficial to them and such as our reason approves ; and that this 

 is the real difference between them and a stone ; for while the 

 actions of the stone may, for all I know to the contrary, be useful 

 to the stone, my reason does not approve the statement that this 

 is the case, for it is a matter about which I know nothing. 



Science may some day enable us to predict the actions of the 

 dog from the study of his body; but I do not see how we are to 

 understand them without studying the conditions under which he 



