

DEVELOPMENT OF MODERN COMPARATIVE PSYCHOLOGY 



509 



sides. Both contemporary and later psy- 

 chologists and biologists usually assign 

 some sort of awareness to the more com- 

 plex instincts, even though denying the 

 presence of a conscious, guiding purpose. 

 Romanes, for example, defines instinct as 

 ' 'reflex action into which there has been 

 imported the element of consciousness." 

 The ability to profit by experience was to 

 him positive evidence of consciousness in 

 the sense of a guiding factor. Morgan 

 held much the same view. The ability to 

 profit by experience was maintained by 

 him to be the criterion of effective con- 

 sciousness, but he argued that for all we 

 know, even the growth changes taking 

 place "in the duly fertilized egg" may 

 involve sentience, or a dim awareness . It 

 is clear, then, that Loeb had done nothing 

 more than take over the criterion of 

 Romanes and make a fallacious application 

 of it by denying consciousness outright 

 where positive evidence of a conscious 

 guiding factor was not forthcoming. In 

 any case, ability to learn ceased to be of 

 value as a criterion of consciousness as 

 soon as modifiability of behavior in the 

 protista had been definitely demonstrated. 

 The search for other criteria of con- 

 sciousness, and of different psychic levels 

 in infra-human forms proved to be hardly 

 more successful. No one seemed to appre- 

 ciate the seriousness of the difficulties 

 involved. The fact that the introspec- 

 tively derived levels of human mental 

 life were arbitrary and based upon philo- 

 sophical prejudices insofar as they were 

 clearly defined at all was generally over- 

 looked. Lubbock, indeed, had urged that 

 the chief obstacle to the use of anthropo- 

 morphic analogy lay in the almost utter 

 lack of definite correlations between men- 

 tal states and bodily behavior factors 

 in the human field. However, occasional 

 criticisms of such a fundamental sort were 

 ineffectual . The application of the canon 



of Morgan presupposes a fairly definite 

 hierarchy of human mental processes and 

 the possibility of recognizing correspond- 

 ing levels in animals. This canon was 

 held by many to place an undue restriction 

 upon subjective interpretation and nothing 

 would establish it so securely as to work 

 out a hierarchy of mental levels that 

 would make it a workable instrument. It 

 is not surprising, therefore, that interest 

 gradually shifted from the problem of 

 determining a criterion of consciousness 

 in animals to speculations concerning 

 criteria of infra-human psychic levels. 



Morgan himself posited three mental 

 levels as follows: (1) sentience, a dim 

 awareness or vague feeling state, probably 

 possessed by all organisms, (2.) effective 

 consciousness, indicated by the ability to 

 profit by experience which supposedly 

 involves conscious guidance, and (3) 

 self-consciousness, associated with highly 

 analytical or rational processes, such as 

 presuppose genuine language ability and 

 therefore probably limited to man. Since 

 he grants that all organisms are prob- 

 ably sentient, and insists that man alone 

 is self-conscious in his sense, the task 

 reduces to that of deciding what or- 

 ganisms meet the test of the second 

 level. And here a structural criterion is 

 brought in also, since Morgan seems to feel 

 that this level requires a central nervous 

 system and brain of some complexity 

 (179). However, it is obvious that the 

 distinction between the first and second 

 level, like the criterion of Loeb, becomes 

 meaningless insofar as evidence is forth- 

 coming that the ability to profit by 

 experience is common to all organisms . 



Several other attempts were made to 

 arrange hierarchies of psychic develop- 

 ment for use in comparative psychology. 

 Hachet-Souplet (136) proposed a classifica- 

 tion based upon the training methods 

 (methods de dressage') to which an animal 



