92 Darwinism and Other Essays. 



little practical transactions of life they go upon 

 the same assumption that the philosopher goes 

 upon when, with his wider knowledge and deeper 

 insight, he rules out the goblins and declares that 

 no matter is ever destroyed. Without this as- 

 sumption in some form we could not carry on the 

 work of life for a single day. The assumption, 

 moreover, is absolutely unconditional ; no occur- 

 rence ever shakes our reliance upon it. I set my 

 clock to-day, and depend on its testimony to-mor- 

 row in starting on a journey : if I miss the train, 

 I may conclude that the clock was not well regu- 

 lated, or that it has begun to need cleaning ; but 

 it never occurs to me that my confidence in the 

 mechanical laws of cog-wheels and pendulums has 

 been at all misplaced. 



This universal and unqualified assumption of 

 the constancy of Nature is, in a certain sense, a 

 net result of experience, inasmuch as we find it 

 tested and verified in every act of our conscious 

 lives. Acting on the principle that " a pound is 

 a pound, all the world around," we find that our 

 mental operations harmonize with outward facts. 

 Doubt it, if we could, and our mental operations 

 would forthwith tumble into chaos. Experience, 

 therefore, by which is meant our daily inter- 

 course with outward facts, continually forces 



