12 COMMON SENSE (aND SCIENCE) 



There is plenty of evidence in children's drawings, and in adult errors 

 in perspective drawing, to show that a person looking at an object 

 thinks he sees more of it than he does. What he knows [or thinks he 

 knows] about the object appears in his drawing, as well as what is 

 visible at the moment; and the significant fact is that neither child nor 

 adult can usually say where his drawing departs from what is actually 

 presented to the sense organ. 



Unable fully to distinguish observation from inference, man has 

 found it all too easy to believe that, for example, the fixity of the 

 earth is obviously a "given fact." 



FROM CONSTRUCTS TO CONCEPTS 



Following the organization of "experience," we have passed from the 

 sensory organ to the brain— from the notion of a bare percept to that 

 of a construct already presupposing the organization given by a con- 

 cept. From early childhood we begin to acquire the multitude of con- 

 cepts necessary for the business of living. For example, the child 

 learns to associate the concept "mother," and the word symbolizing 

 it, with a "particular person." But in what way a particular person? 

 Not one who always acts the same: sometimes she does things that 

 please, sometimes things that hurt; sometimes her voice is soft and 

 loving, sometimes harsh and commanding. She does not always look 

 the same. She does not always wear the same dress, or even always 

 wear dresses; her coiflFure, her make-up, her expression all vary. And 

 all these variations in the child's experience of "mother" must be sub- 

 tracted, allowed for, or dismissed as irrelevant in the formation of 

 the concept. An addition is made when he grasps that underlying the 

 "superficial variations ' in the experience of mother there is an un- 

 changing "something." To achieve even so primitive a concept, the 

 child must perform a feat of abstraction and synthesis that Hebb 

 notes is difficult enough to baffle an infant ape. 



Dr. R. and Mr. T. are regular attendants in a chimpanzee nursery; 

 the infants are attached to both, and eagerly welcome being picked 

 up by either. Now, in full sight of the infants, Dr. R. puts on Mr. T.'s 

 coat. At once he evokes fear reactions identical with those made to a 

 stranger, and just as strong. 



Meyerson tells us that all science represents the eflFort to discover, 

 or create, identity in experience. That pursuit is already reflected in 



