i 5 4 THE POPULAR SCIENCE MONTHLY. 



other manifestations as to necessitate a specific designation. By adopt- 

 ing the term personality, we should affirm our belief in the existence 

 of some form of being, which, for us, is persistently unlike every other 

 form of being with which we come into relation. Here the element 

 of speculation, which is a necessary part of all reasoning, appears. 

 Whether we accept correlation or personality, we accept what can no 

 more be directly Tcnown than the mortality of men now living, or the 

 return of the seasons. All reasoning is beyond the facts, and is in this 

 a speculation ; but reasoning need be no more an unsafe guide on such 

 subjects as the one before us than on any of the complex affairs where 

 we gladly trust its teachings. Our demand of Reason must be that, 

 though she lead us beyond the facts, she shall never lead us contrary 

 to the facts. Again, I would say, it should be recognized that neither 

 of the conclusions above indicated is a solution of the mystery attend- 

 ant upon consciousness. The pride of the little scientists induces them 

 all too often to declare that, by the first of these alternatives, they 

 have cleared away the obscurity which they love to call metaphysical 

 and let in the white light of comprehension. 



So, in turn, the other party, seizing hold of the fact of personality, 

 forthwith affirm that, by it, man's immateriality, immortality, and di- 

 vinity, are forever made visible in the light of consciousness. All this 

 is quite aside from that inferential process which, as reasoning beings, 

 we should prescribe for ourselves. Is the relation between brain and 

 consciousness one of correlation ; may we, according to the evidence, 

 believe it to be one of correlation ? Physiological materialism is an 

 extension of the doctrine of correlation to consciousness. It is needful 

 to know what is meant by correlation. Correlation is a necessary, 

 reciprocal production. " Any force capable of producing another 

 may be produced by it. Each mode of force is capable of producing 

 the others, and none of them can be produced but by some other 

 as an anterior force. The various affections of matter, heat, light, 

 electricity, have a reciprocal dependence ; either may produce or be 

 convertible into any of the others." The materialism of physiology 

 extends this doctrine of correlation to consciousness. The well-worn 

 language of Professor Huxley (" Darwin and his Critics ") is again in 

 point. " As the electric force, the light-waves and the nerve-vibra- 

 tions caused by the impact of the light-waves on the retina are all ex- 

 pressions of the molecular changes which are taking place in the 

 elements of the battery, so consciousness is, in the same sense, an 

 expression of the molecular changes which take place in that nervous 

 matter which is the organ of consciousness." A short sentence from 

 Dr. Carpenter to the same effect : " There is just the same evidence of 

 what has been termed correlation between nerve-force and that pri- 

 mary state of mental activity which we call sensation that there is 

 between light and nerve-force." Now, the proposition, fundamental to 

 my paper, is that such a conclusion can not rationally be drawn, un- 



