CHAPTER XX 



RELATION OF BEHAVIOR IN LOWER ORGANISMS TO PSYCHIC 



BEHAVIOR 



In describing the behavior of lower organisms we have used in the 

 present work, so far as possible, objective terms — those having no im- 

 plication of psychic or subjective qualities. We have looked at organ- 

 isms as masses of matter, and have attempted to determine the laws of 

 their movements. In ourselves we find movements and reactions re- 

 sembling in some respects those of the lower organisms. We draw away 

 from heat and cold and injurious chemicals, just as Paramecium does. 

 Our behavior depends on physiological states, as does that of Stentor. 

 But in ourselves there is the very interesting additional fact that these 

 movements, reactions, and physiological states are often accompanied by 

 subjective states, — states of consciousness. Different states of con- 

 sciousness are as varied as the different possibilities of reaction ; indeed, 

 more varied. In speaking of behavior in ourselves, and as a rule in 

 higher animals, we use terms based on these subjective states, as pleas- 

 ure and pain, sensation, memory, fear, anger, reason, and the like. 



The peculiarity of subjective states is that they can be perceived 

 only by the one person directly experiencing them, — by the subject. 

 Each of us knows directly states of consciousness only in himself. We 

 cannot by observation and experiment detect such states in organisms 

 outside of ourselves. But observation and experiment are the only 

 direct means of studying behavior in the lower organisms. We can 

 reason concerning their behavior, and through reasoning by analogy 

 we may perhaps conclude that they also have conscious states. But 

 reasoning by analogy, when it is afterward tested by observation and 

 experiment, has often shown itself fallacious, so that where it cannot 

 be tested, we must distrust its conclusiveness. Moreover, in different 

 men it leads to different conclusions, so that it does not result in ad- 

 mitted certainty. Hence it seems important to keep the results of obser- 

 vation and experiment distinct from those of reasoning by analogy, so 

 that we may know what is really established. On this account it is 

 customary among most physiologists not to use, in discussing the be- 

 havior of the lower organisms, psychic terms, or those implying sub- 



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