60 BULLETIN OF THE UNIVERSITY OF WISCONSIN. 



of the requirements of food, air, and exercise, or in other ways, 

 doubtless have occasion frequently to realize. 



Fatigue works most serious harm in the elaborative or re- 

 flective processes. Reason requires co-ordination of ideasj it 

 necessitates holding before consciousness in a single act of 

 thought two or more objects, viewing them together to discover 

 the relations which they bear toward one another. It can be 

 seen that to accomplish this requires good control and balance 

 neurologically, and so psychically. But this is just what fa- 

 tigue makes impossible, not absolutely of course, but relatively. 

 Any person's experiences will afford illustrations in plenty. We 

 all know how difficult it is, or even how impossible it is to attend 

 to matters requiring elaborate reasoning at a time when the vi- 

 talities are run low. We generally defer the consideration of 

 such matters until a more favorable period when mental strength 

 has been regained. We attack our mathematical problems in 

 the morning rather than at 5 o'clock in the afternoon. Even 

 social custom has recognized this and has assigned the later hours 

 of the day to occupations and pastimes requiring little concen- 

 trated effort of mind. 



§ 5. Neural Fatigue : Emotional Effects. — It will not be need- 

 ful here to do more than to refer briefly to the fact that the 

 cerebral states which give rise to physical and intellectual in- 

 co-ordination and errancy have a similar effect in principle upon 

 the emotional life. People are generally aware of this, and they 

 freely condone the bad temper of individuals at certain seasons 

 because of their unhappy physical condition. If one studies 

 the matter at close range, he can see that the people who sur- 

 round him are sometimes transformed in temperament under 

 an ordeal which overdraws their account in the nervous system. 

 It will of a certainty impress one who will turn his attention to 

 the matter to observe how in a siege of neurasthenia anti-social 

 qualities, as irritability, jealousy, hatred, anger, and the like 

 take possession of an individual who in fairer weather is well 

 poised and not too conscious of self in relation to others in his 

 neighborhood. 



