The Mental Life of the Monkeys 175 



rarely or never learns in this fashion. The present study 

 of the primates has been a comparative study with two 

 main questions in view: (i) How do the monkeys vary 

 from the other mammals in the general mental functions 

 revealed by their methods of learning ? (2) How do they, 

 on the other hand, vary from adult civilized human beings ? 



The experiments to be described seem, however, to be of 

 value apart from the possibility of settling crucial questions 

 by means of the evidence they give. To obtain exact 

 accounts of what animals can learn by their own unaided 

 efforts, by the example of their fellows or by the tuition 

 of a trainer, and of how and how fast they learn in each 

 case, seems highly desirable. I shall present the results 

 in the manner which fits their consideration as arguments 

 for or against some general hypotheses, but the naturalist 

 or psychologist lacking the genetic interest may find an 

 interest in them at their face value. I shall confine myself 

 mainly to questions concerning the method of learning of 

 the primates, and will discuss their sense-powers and un- 

 learned reactions or instincts only in so far as is necessary 

 to its comprehension. 



It has been impossible for the author to make helpful 

 use of the anecdotes and observations of naturalists and 

 miscellaneous writers concerning monkey intelligence. 

 The objections to such data pointed out in Chapter II, 

 pp. 22-26, hold here. Moreover it is not practicable 

 to sift out the true from the false or to interpret these 

 random instances of animal behavior even if assuredly true. 

 In the study of animal life the part is only clear in the 

 light of the whole, and it is wiser to limit conclusions to 

 such as are drawn from the constant and systematic study 

 of a number of animals during a fairly long time. After 

 a large enough body of such evidence has been accumulated 

 we may be able to interpret random observations. 



