RELATION TO PSYCHIC BEHAVIOR 335 



a change of behavior. These laws apparently form the fundamental 

 basis of intelligent action. This fundamental basis then clearly exists 

 even in the Protozoa ; it is apparently coextensive with life. It is diffi- 

 cult if not impossible to draw a line separating the regulatory behavior 

 of lower organisms from the so-called intelligent behavior of higher 

 ones ; the one grades insensibly into the other. From the lowest organ- 

 isms up to man behavior is essentially regulatory in character, and what 

 we call intelligence in higher animals is a direct outgrowth of the same 

 laws that give behavior its regulatory character in the Protozoa. 



Thus it seems possible to trace back to the lowest organisms some of 

 the phenomena which we know, from objective evidence, to exist in the 

 behavior of man and the higher animals, and which have received special 

 names. It would doubtless be possible to extend this to many other 

 phenomena. Many conditions which we can clearly distinguish in 

 man must be followed back to a single common condition in the lower 

 organism. But this is what we should expect. Differentiation takes 

 place as we pass upward in the scale in these matters as in others. 

 Because we can trace these phenomena back to conditions found in 

 unicellular forms, it does not follow that the behavior of these organisms 

 has as many factors and is as complex as that of higher animals. 

 The facts are precisely parallel with what we find to be true for other 

 functions. Amoeba shows respiration, and all the essential features of 

 respiration in man can be traced back to the condition in such an organ- 

 ism. Yet in man respiration is an enormously complex operation, 

 while in Amoeba it is of the simplest character possible apparently 

 little more than a mere interdiffusion of gases. In the case of behavior 

 there is the same possibility of tracing all essential features back to the 

 lower organisms, with the same great simplification as we go back. 



THE QUESTION OF CONSCIOUSNESS 



All that we have said thus far in the present chapter is independent 

 of the question whether there exist in the lower organisms such subjec- 

 tive accompaniments of behavior as we find in ourselves, and which 

 we call consciousness. We have asked merely whether there exist in 

 the lower organisms objective phenomena of a character similar to what 

 we find in the behavior of man. To this question we have been com- 

 pelled to give an affirmative answer. So far as objective evidence goes, 

 there is no difference in kind, but a complete continuity between the 

 behavior of lower and of higher organisms. 



Has this any bearing on the question of the existence of conscious- 

 ness in lower animals? It is clear that objective evidence cannot give 



