THE STABILITY OF TRUTH. 361 



and at the same time the personal equation or individual 

 source of error is largely eliminated. The use of instru- 

 ments of precision is the special charac- 



Hyperaesthesia ^gj-istic of the advance of science. No 

 of science 



instrument of precision can give us the 



ultimate essence of any part of the universe. No scien- 

 tific experiment can do away with the measure of human 

 experience as the basis of intelligibility. At the same 

 time we can throw large illuminations into " the dimly 

 lighted room " in which, according to Balfour, the phe- 

 nomena of consciousness takes place. By the simple 

 process of photography, for example, we may reproduce 

 the objects of our environment. That such pictures do 

 express phases of reality admits of no doubt ; for in the 

 photographic camera, all personal equation is eliminated. 

 As to form of outline and reflection of light, "the sun 

 paints true," and the paintings thus made by means of 

 the action of non-living matter produce on our senses 

 impressions coinciding with those of the outside world 

 itself. 



How do we know that this is truth ? Because belief 



in it adds to the safety of life; we can trust our lives to 



it. If it were an illusion it would kill. 



Trust in reality ^g^^^use action based on illusion leads to 

 makes life safe. 



death. 



One can trust his life, for example, to the message 

 sent on a telegraph wire. All who travel by rail do this 

 daily. One can trust his life to the reading of a ther- 

 mometer. The chemist's tests will select for us foods 

 among poisons. We may trust these tests absolutely. 

 We may safely and sometimes wisely take poisons into 

 our bodies if we know what we are doing. By the ad- 

 vice of a physician, trusting in the weigher's instrument 

 of precision, poisons may do no harm. One grain of 

 strychnine may be an aid to vital processes ; a dozen 



