Psychology of Animals. 207 



Lloyd Morgan's works on Animal Life and Intelligence, 

 Comparative Psychology ', and Habit and Instinct, cannot 

 be too strongly recommended to the student of the 

 mental life of animals. 



The first task of the inquirer is to make sure of the 

 data, to distinguish observation from inference, to sift 

 out precise evidence from the carelessly anec- open 

 dotal, and to give prominence to cases in Questions, 

 which some simple experiment was used to check the 

 impressions of the observer. The second task is to 

 give the simplest psychological interpretation that is 

 adequate to cover the facts. Although there is still 

 great room for improvement, it must be allowed that 

 there has been of recent years marked progress in 

 regard to both accuracy of observation and criticism 

 of interpretation. 



With the data before him the naturalist has then to 

 inquire into the psychological interpretation, and there 

 are three questions which are naturally raised by each 

 case, (i) Is the behaviour such that, if it occurred in 

 man, its psychological aspect could be legitimately 

 expressed without postulating general ideas, abstract 

 reasoning, or conceptual judgment? Does it imply 

 intelligence, or more than that reason? It may be 

 safely said that the majority of naturalists who have 

 given attention to the subject are agreed in the con- 

 clusion that there are no certain cases of animal 

 behaviour which necessitate the assumption of a con- 

 ceived, as contrasted with a perceived purpose. 



(2) A second question is, whether the instance of 

 animal behaviour under discussion shows any sign that 

 the creature is utilizing its individually acquired experi- 

 ence, or is modifying its mode of action in reference to 

 what it has learned, or in relation to some quite novel 

 situation. If this question be answered in the affirma- 

 tive, then one must allow that the animal is in such 

 behaviour intelligent. And of this there are endless 

 illustrations among the higher animals. On the other 

 hand, if the behaviour, however marvellous and effective 

 it may be, does not show profiting by experience nor 

 adaptation to quite novel ends, the probability is that 



