Difficulties and Methods 25 



In other words, when in doubt take the simpler interpretation. 

 For example, a dog detected in a theft cowers and whines. One 

 possible mental accompaniment of this behavior is remorse; 

 the dog is conscious that he has fallen below a moral standard, 

 and grieved or offended his master. . A second is the antici- 

 pation of punishment ; the dog has a mental representation of 

 the consequences of his action upon former occasions, and 

 imagining himself likely to experience them anew, is terrified 

 at the prospect. $ A third possibility is that the dog's previous 

 experience of punishment, instead of being revived in the form 

 of definite images, makes itself effective merely in his feelings 

 and behavior; he is uncomfortable and frightened, he knows 

 not definitely why. It is evident that these three possibili- 

 ties represent three different grades of complexity of mental 

 process, the first being by far the highest. Lloyd Morgan's 

 canon enjoins upon us irj such a case to prefer the third 

 alternative, provided that it will really account for the dog's 

 behavior. 



Now why should the simplest interpretation be pre- 

 ferred? We must not forget that the more complex ones 

 remain in the field of possibility. Positive assertions have no 

 place in comparative psychology. We cannot say that the 

 simplicity of an hypothesis is sufficient warrant of its truth, 

 for nature does not always proceed by the paths which seem 

 to us least complicated. The fact is that Lloyd Morgan's 

 principle serves to counterbalance our most important source 

 of error in interpreting animal behavior. It is like tipping 

 a boat in one direction to compensate .for the fact that some 

 one is pulling the opposite gunwale. /We must interpret the 

 animal mind humanly if we are to interpret it at all. Yet we 

 know that it differs from the human mind, and that the dif- 

 ference is partly a matter of complexity. Let us therefore 

 take the least complex interpretation that the facts of animal 



