In this discussion, I have 
suggested several reasons why 
drawing or painting is difficult 
and why the productions of 
children and of artists of 
antiquity contain certain kinds 
of "errors." However, I must add 
an important disclaimer. 
Drawings or paintings that are 
poor representations of objects 
and scenes by our standards 
and expectations of realism 
need not be the result of the 
perceptual or cognitive 
limitations I have suggested; 
rather, they may be the result 
of an intention or convention 
to draw in a particular way. 
Perhaps the Egyptians drew 
pictures of people the way they 
did because they believed that 
side views of faces and feet and 
frontal views of torsos were the 
most informative about the 
human body. The lack of 
perspective in painting does 
not necessarily mean the 
absence of the ability to use it. 
The realistic aim is not the 
only aim in art, and it only 
appears here and there in 
different cultures and at 
different times in history. 
Similarly, children are not 
always concerned with making 
realistic drawings but instead 
may be motivated to express 
themselves in form and color. It 
would be absurd to infer from 
Picasso’s more abstract 
paintings that he could not 
draw realistically when some of 
his other work shows how great 
a master of realistic portrayal 
he was when he chose to be. If 
one did not know about the 
realistic paintings, however, 
one might make just that wrong 
inference from the abstract 
ones.

    In this and the preceding 
chapters, I have necessarily 
referred often to object and 
shape (or form) perception. 
From this one might draw the 
conclusion that such 
perception is based solely on 
the reception of the shape of 
the object’s image on the retina 
as given by its contours. As will 
be seen in the next chapter, 
nothing could be farther from 
the truth. Even so simple a 
perception as that of a single 
two-dimensional shape poses 
many difficult problems.