IN SEARCH OF TRUTH 135 



" Poisons would seem as foods, foods as poisons ; pleasures as sins, and 

 sins as pleasures. The whole sanity and accuracy of life would be de- 

 stroyed. For the security of action is conditioned by the exactness of 

 our perceptions of the relations of external things and by the correct- 

 ness of our reasoning in regard to these perceptions." 



Mr. Grimshaw, falling back on the lore he had learned in school, 

 said: 



" In psychology the term reality is sometimes applied to a sense per- 

 ception which is based on an outside influence acting then and there. 

 In this sense the reality is not the external influence itself, but our 

 direct or normal perception of it. Thus, the impression made by the 

 sound of a gun would be a reality when the pressure' of air waves reached 

 the brain, though the explosion may have taken place some seconds 

 before. This reality as it comes to the brain should bear a definite rela- 

 tion to its source. In other words it must give the mind such informa- 

 tion that the actual occurrence may be correctly interpreted. On its 

 correct interpretation the fitness of our response in action must be 

 conditioned. The term e common sense ' is applied to the normal work- 

 ing of these brain processes. An external stimulus produces a reality. 

 The reality is transmitted to the brain where it is considered in its 

 proper relations. Afterwards an impulse to action passes along the 

 motor nerves to the muscles, which are the servants of the brain. 



" In simple matters, as those pertaining to the apple, the dictates of 

 common sense are obvious enough. The feelings are not moved by an 

 apple, and our recognition of its nature is clouded by no illusions. But 

 there are many relations in life in which ' common sense' does not find 

 the problem so easy. If we examine the actions of ourselves and of our 

 fellows, we shall find that the ' common sense ' of different men does 

 not act in parallel ways, and what seems to one wise or natural becomes 

 grotesque or absurd to another." 



Mr. Grimshaw then gave a number of illustrations of thought or 

 action in which the 'common sense' may be deceived: 



" You are in a railway train which is waiting on a side-track. 

 Another train comes in sight, its motion seems transferred to your own 

 train, but in the opposite direction. This motion continues until the 

 other train has passed. It ceases suddenly, when you can almost feel 

 the jolt of its stopping. But from other observations you know that 

 your train has not moved in all this time. 



" This is a simple illusion, easily corrected by the mind before it 

 passes over into action. Let us look at some others. The story is told 

 of a merchant who, smacking his lips over a glass of brandy, said to 

 his clerk : ' The world looks very different to the man who has taken a 

 good drink of brandy in the morning.' ' Yes,' said the clerk, ' and he 

 looks different to the world, too.' Now, which is right? Is the world 



