XVlll INTRODUCTION 



Not only, then, is the emotional side of the 

 child a thing to be cultivated, but it is equally 

 true that this can be successfully done only 

 through the emotional nature of the teacher. 

 As the teacher reaches the intellect of his pupils 

 through his own intellect, so he touches their 

 emotions by means of his own emotions. That 

 is why the teacher must himself love nature, if 

 he is to succeed in influencing others with a love 

 for it. As Dr. Bigelow puts it, " Do not talk to 

 him [your pupil] about the lovableness of nature, 

 if you have not the genuine article in your own 

 heart, heart, not head." That remarkable char- 

 acteristic of the human mind called by some psy- 

 chologists plastic imitation, in consequence of 

 which we tend to believe and feel as the people 

 around us believe and feel, which explains the 

 tidal-wave spread of enthusiasm that manifested 

 itself in such great movements as the Crusades, 

 in the prevalence of belief in witchcraft at cer- 

 tain periods in the history of the world, in the 

 contagion-like communication of panic from man 

 to man in a theatre, when a cry of danger is 

 heard, and in the remarkable counteracting in- 

 fluence that may be exerted by a person who 

 keeps his presence of mind, this characteristic 



