192 Science Religion and Reality 



our own ; unless we discover or imagine beings looking at it from 

 another point of view, we cannot differentiate between the ex- 

 ternal world and the apprehension of it in our own consciousness. 

 If I were the only conscious being in the universe the only data 

 presented for investigation would consist in the content of my 

 consciousness, and there would be no reason to suspect that the 

 data had reference to anything external to my consciousness. It 

 is true that I might make the hypothesis that there was an external 

 world responsible for what was going on in my consciousness ; but 

 it would be an idle hypothesis, since the knowledge that could be 

 asserted of this supposed external world would be a mere duplica- 

 tion of the knowledge that could be much more confidently asserted 

 of the world of my consciousness. The motive for the conception 

 of an external world — a world which will remain significant when 

 my consciousness ceases to be — lies in the existence of other con- 

 scious beings. We compare notes and we find that our experiences 

 are not independent of one another. Much that is in my conscious- 

 ness is individual, but there is an element common to other con- 

 scious beings. That common element we desire to study, to 

 describe as fully and accurately as possible, and to discover the laws 

 by which it is modified as it appears now in one consciousness, now 

 in another. That common element cannot be placed in one man's 

 consciousness rather than another's ; it must be placed in neutral 

 ground — an external world. It is the essence of such an external 

 world that we are all partners in it on the same footing. The 

 external world is not a mere duplication of the presentation of it 

 in any one man's mind ; it is a symposium of the presentations to 

 individuals in all sorts of circumstances. 



Individuals may differ in physical circumstances (position, 

 motion, size) and also in more subtle mental characters. We do 

 not usually attempt to extend the symposium to differences of the 

 latter kind. We have a fairly definite idea of a normally equipped 

 human being, and it is to his standard of appreciation that the con- 

 ception of the external world of physics particularly relates. But 

 as regards physical circumstances it would be illogical to attach 

 greater weight to one position, motion, and size rather than another. 

 We are beings who happen to be situated in a particular part of the 

 stellar universe, compelled to journey with the motion of a rather 

 small globe ; our size is presumably regulated by the value of 

 gravity and other physical conditions peculiar to that globe. We 



