300 BIOLOGICAL ASPECTS OF HUMAN PROBLEMS 



use from infancy to old age, and is limited mainly by 

 the fatigue or the physical imperfection of the senses. 

 The capacity to observe is not the same in all persons, 

 for some persons are endowed by nature with finer 

 and quicker receptive mechanisms than are others. 

 We all remember the celebrated case of Robert 

 oudin, the French prestidigitator, who systemati- 

 cally trained his son to note with great rapidity and 

 accuracy large numbers of objects, exposed in shop 

 windows, in rooms, etc. The response of the brain 

 to this method of training is something astonishing, 

 and all children should have some training of this 

 kind, although it is only rarely advisable to push it 

 to the extreme sought by Houdin. Very intelligent 

 persons overlook much that is of interest and often 

 of real importance to them simply from defective 

 training in observation, and it is certain that teachers 

 would do well to attach more importance to helping 

 pupils to note more of the objects with which the 

 world fairly bristles. It is not in order to use 

 this faculty on all occasions that it should be ac- 

 quired ; it is to have it at call as a means to an end, 

 or as a pleasure in itself. Some persons with excel- 

 lent powers of observation may prefer to be occupied 

 with their thoughts; if they do not observe, it is 

 because they prefer not to, not because they cannot. 

 And it cannot be denied that the ability to inhibit 

 observation at will is as important to the educated 

 man or woman as the faculty of highly trained ob- 

 servation. 



