890 



SCIENCE. 



[N. S. Vol. VIII. No. 208. 



If our race should ever find itself where 

 the old order changes ; if our reasonable ex- 

 pectations should disappoint us ; if what we 

 call the ' order ' of nature should prove to 

 be no more than natural selection would 

 lead us to expect, and if a different selective 

 standard should sometime modify this order, 

 every zoologist knows that the human spe- 

 cies would not be the first to meet this evil 

 fate. 



If, W'ith Aristotle, we believe ' that is 

 natural which holds good ;' if, with Erigena, 

 we hold that nature is the sum of all things, 

 we cannot believe that life and conscious- 

 ness and reason and volition are anything 

 but part of nature. The question the zo- 

 ologist would like to answer is what their 

 place in nature is. So far as I am aware, 

 no one believes that these aspects of nature 

 exist in themselves, without antecedents, 

 for we know that many of their antecedents 

 are phj'sical, and we want to find out, if we 

 can, whether this is true of all of them or 

 not. For my own part, I fail to see what 

 bearing this wish has ou the question 

 whether the order of nature is ' fixed ' or 

 unfixed ; nor can I see how proof that the 

 conditions which, being given, are good 

 reasons for expecting reason or the moral 

 sense are mechanical should show that 

 reason and morality are useless. 



They who take refuge in an imponderable 

 ether as soon as they find it difiBcult to dis- 

 cover, in ponderable matter, the key to all 

 the antecedents to certain phenomena of 

 light and electricity have no reason to cry 

 out that the fixed order of nature is threat- 

 ened, because the modest zoologist has not 

 yet been able to find, in ponderable matter 

 and physical energy, the key to all his 

 problems. 



Berkelej^ tells us that human knowledge 

 has its basis in experience, and that its 

 scientific value is to be measured by the 

 amount of this experience ; and Huxley as- 

 sures us that there is but one kind of 



knowledge and but one way to acquire it" 

 They hold our practical test of truth to 

 be evidence, although a pious evolutionist, 

 who admits that, for all he knows, they 

 may be right, is a heretic ; for Herbert 

 Spencer tells him that the Philosophy of 

 Evolution stands or falls with the assertion 

 that the ultimate criterion of truth is in- 

 ability to conceive its negative. 



If you will read Part VII. of his ' Prin- 

 ciples of Psychology ' with care you will 

 note that its author tells us that unless we 

 admit this we cannot be his disciples. It 

 is not enough to admit ignorance of things 

 ultimate, or to confess that, for all one 

 knows, inability to conceive its negative 

 may sometime prove to be the ultimate cri- 

 terion of truth. One maj' admit that he is 

 unable to discover any line which separates 

 the responsive actions of living things in 

 general from the rational actions of think- 

 ing men ; that he does not know how or 

 where instinct and impulse and emotion 

 give place to reason. 'One may have as 

 little faith in the idealism of Berkeley as he 

 has in Spencer's realism, or in the material- 

 ism of G-erman phj'sics, or in the monism 

 of the psychologists; but unless he knows 

 what the relation between mind and matter 

 is he cannot join the throng of worshippers 

 before the shrine of this modern idol of the 

 theater, for its leader tells him that sus- 

 pension of judgment on this difficult ques- 

 tion is as fatal as disbelief. 



Proof that we should not be here if our 

 remote ancestors had not responded to the 

 order of nature as they did is no' proof 

 that our minds are a measure of nature, or 

 that our responses will be valuable in the 

 future, or that nature is determinate. 



Now the difference between belief that 

 the ultimate test of truth is the inconceiva- 

 bility of its negative, and belief that our 

 practical test of truth is evidence, is this : 

 that while inability to conceive the negative 

 of a proposition may be absolute to us, as 



