XVI 



SYSTEMATIC THOUGHT 



369 



reflection, the mind begins to recognise that its opinions 

 are in a sense of its own making. The natural man does 

 not question that he is in daily and hourly contact with 

 reality ; he makes no question about the validity of the 

 conclusions which he draws from this seeming reality by 

 steps which appear no less self evident. Common sense 

 may be convinced of error as of illusion, but while it 

 revises its results, it neither calls its own methods into 

 question nor doubts its senses. It is satisfied to be right 

 in its own world. It does not ask about the limits of that 

 world, nor inquire whether its experience is the same thing 

 as reality. Yet the human mind, like the human body, is 

 the outcome of a long and highly specialised evolution. 

 It is a very elaborate structure, with determinate functions 

 of its own, and its every act and thought, every inference, 

 perception, and feeling depends as much upon this structure 

 as upon the outer world which acts upon it, and stimulates 

 it to reaction. We thus contribute to the making of our 

 own experience that experience which at first we all take 

 as though it had a sort of absolute value wholly in- 

 dependent of ourselves. The full realisation and dis- 

 cussion of this difficulty is the central problem of 

 philosophy, but it is important to recognise that it makes 

 itself felt in one way and another even in the special sciences. 

 The world of science is not the same as the world of 

 common sense. The material universe as conceived by 

 molecular physics is not the universe as known to sight 

 and touch, only rather more completely known. The 

 conceptions of Life, of Personality, of Society are not 

 merely deepened and widened in scientific treatment, but in 

 great measure they have to be taken to pieces and thought 

 out anew. In many sciences, we get, by the use of 

 instruments, into a new world of perceptions, and are thus 

 forced to realise incidentally the relativity of our own 

 sense-experience. In all science we constantly find that 

 the conceptions which have grown up uncritically, and 

 which we began by using confidently as moulds into which 

 reality must fit, are spontaneous products of our limited 

 experience, which a wider experience would transform out 

 of all recognition. 



B B 



