MAN AND SCIENCE: A REPLY. 



63 



proof that any state of consciousness is the cause 

 of change in the matter of the organism," ' and 

 that " the feeling we call volition is not the cause 

 of a voluntary act, but the symbol of that state 

 of the brain which is the immediate cause of that 

 act." In like manner Prof. Tyndall says : " I have 

 no power of imagining states of consciousness in- 

 terposed between the molecules of the brain, and 

 influencing the transference of motion among the 

 molecules;" these states of consciousness being 

 further described as merely " by-products which 

 are not essential to the physical process going on 

 in the brain." 2 



All which, translated into the vernacular, 

 amounts to this : A speaker in an assembly, or a 

 discord in a concert, disturbs me, and to escape 

 the unpleasant sensation I leave the room, and I 

 think I do so of my own free-will. 



"No," says the modern philosopher, "you are 

 quite mistaken. You say you have a sensation, 

 and I cannot absolutely deny it, but this sensation 

 has nothing whatever to do with your action — 

 neither has what you think to be your volition. 

 The brain acts automatically in causing you to 

 leave the room, and what you are pleased to con- 

 sider your sensation and volition are only delusive 

 by-products that have no influence on the action." 



I can but reply : " Many thanks for the infor- 

 mation, but I know by daily and hourly experience 

 that of several courses open to me I can select 

 one and reject the others, and I offer to submit 

 this faculty to any test you can suggest. He dis- 

 covers only, who proves ; and, unless you can 

 prove the evidence of my senses and of my fun- 

 damental intuitions to be a perpetual lie, I must 

 decline to accept the conclusion. Permit me to 

 ask if common-sense is finally and forever ex- 

 cluded from the domain of philosophy ? " 



Nevertheless it must be conceded that this is 

 not a complete answer to our philosopher. Doubt- 

 less theology has something to say on the ques- 

 tion, ethics more, and common-sense most of 

 all ; yet, when all these have said their last word, 

 science will claim, and most justly claim, to pro- 

 nounce the final verdict on this as on every ques- 

 tion relating to the nature and constitution of 

 man. But, if we are called upon to relinquish not 

 only every form of religious belief, but all the 

 principles upon which society and its laws have 

 been founded, and the most deeply-rooted and 

 fundamental intuitions of our consciousness, we 

 on our part have the right to claim that the sci- 

 ence in the name of which these requirements are 



1 Fortnightly Review, November, 1874, p. 577. 



2 " Fragments of Science," p. 561. 



made shall be sternly accurate in fact, rigid in 

 method, cogent and conclusive in logic. To in- 

 quire if these conditions have been and are ful- 

 filled, is my object in the remainder of this essay. 

 And first as to method. 



It is not easy to construct a definition of sci- 

 entific method in the abstract that shall be free 

 from all objection ; it is, however, perfectly easy 

 to understand what this method ought to be prac- 

 tically, by considering a few concrete instances. 



While investigating the spectrum of a certain 

 seleniferous deposit in 1861, Mr. Crookes noticed 

 " a single sharp and brilliant green line," differing 

 essentially from any line before observed. Had 

 he been addicted to loose generalization, instead 

 of being a careful observer, he might have rea- 

 soned in this wise : " This line has never been seen 

 in the spectrum of any substance before examined, 

 and I cannot reproduce it by the use of any one 

 or any combination of these. But, as I know that 

 there are only (about) sixty elements, and that of 

 these the whole world is composed, it must be due 

 to some of them influenced by unknown and un- 

 knowable conditions." This would naturally close 

 the investigation. Instead of this, Mr. Crookes 

 adopted the scientific method of recognizing that 

 new phenomena implied new elements of causa- 

 tion. He said : " Tliere is something else here, that 

 I have not known before — what is it ? " This re- 

 sulted in the discovery of a new metal, thallium. 

 The same method applied by Bunsen, Richter, and 

 others, led to the discovery of several other new 

 metals, osmium, caesium, indium, and rubidium, 

 thus greatly enlarging our knowledge of element- 

 ary bodies. 



About thirty years ago Leverrier and Adams 

 observed certain perturbations in the motions of 

 the planet Uranus, which they could not trace to 

 the influence of the other known planets. They 

 did not say : " Our system consists only of the sun 

 and seven primary planets ; therefore these per- 

 turbations are due to some of these under unde- 

 fined conditions.' 1 '' They said, " There is something 

 else — what is it ? " Following out this thought 

 by perhaps the most beautiful train of investiga- 

 tions ever effected, they were enabled almost at 

 the same time to direct a telescope to that point 

 in the heavens where was found the disturbing 

 element, the new planet Neptune. 



To come nearer to the subject — the phenom- 

 ena of light are known to be due to certain mo- 

 tions, tremors, undulations, or vibrations ; and 

 where motion is there must be something that 

 moves. What is that something ? Sound is also 

 due to movements of a somewhat similar char- 



