Hildebrand, whose Problem of Form in Painting and Sculpture  
had first clearly explained the disorder in ordinary human sense 
perception, and the role of art in clarifying this confusion. 
Hildebrand had shown how tactility was a kind of synesthesia 
or interplay among the senses, and as such, was the core of 
the richest art effects.  For the low definition imagery of the 
tactile mode compels the viewer into an active participant role. 
When Africans watch movies as if they were low definition 
forms for active participation, we are amused by the 
incongruity. Working from effect rather than from cause, which 
we have already seen as native to the Russian, was for us a 
novel mode of procedure in the later nineteenth century, and 
will come in for fuller discussion later in this book.

      A recent work by Georg von Békésy, Experiments in  
Hearing,  offers an exactly reverse answer to the problem of