much as the prisoner can see flickers and hear tappings, 
     but cannot, unfortunately, see or hear football matches, 
     so we can observe our visual and other sensations, but 
     cannot, unfortunately, observe robins. (18)

     We become extremely conscious of cultural models and 
bias when moving from one dominant form of awareness to 
another, as between Greek and Latin or English and French. So 
we are no longer amazed that the oriental world has no 
concept of “substance” or of “substantial form,” since they 
experience no visual pressure to break up experience into such 
packages. And we have seen how his training in the world of 
prints enabled William Ivins to translate the meaning of 
typography as nobody else has done. In his Prints and Visual  
Communication  (p. 54) he offers a general principle: