60 The Animal Mind 



fineness of pitch discriminations exist in its possessor's 

 mind. No investigator has yet succeeded in relating the 

 different qualities of smell and taste to differences in the 

 end organs. 



4 15. Behavior as Evidence of Discrimination 



The argument from behavior is as follows : If an animal 

 reacts in a different way to two qualitatively unlike stimuli, 

 then, providing that it is conscious at all, it may be supposed 

 to receive qualitatively unlike sensations from them. If it 

 always reacts in the same way to both, then both may be sup- 

 posed to be accompanied by the same sensation quality. 

 Obviously these statements need further discussion. For 

 one thing, it may be urged that in our own case the same 

 external reaction is often made to stimuli that are nevertheless 

 consciously discriminated. A man may eat with relish and 

 without observable difference in behavior, for example, foods 

 that yet give him perfectly distinguishable smell and taste 

 sensations. Precisely this objection holds against a method 

 of experimentation, formerly a good deal used, which may 

 be called the Preference Method of testing discrimination. 

 Vitus Graber, for instance, attempted to find whether ani- 

 mals belonging to a variety of species could discriminate 

 colors, by offering them the choice of two compartments 

 illuminated each with a different color. Clearly, if the ani- 

 mals chose one compartment as often as the other, it would 

 be rash to conclude that the two lights produced for them 

 indistinguishable sensation qualities. There might simply 

 be the absence of any preference, along with perfect dis- 

 crimination. The fact is that in all experiments upon 

 animals, whether to determine their power of distinguishing 

 stimuli or their power of learning by experience, the first 

 requisite is to give the animal what we commonly call a 



