Why we have trouble drawing 
subtle shapes is not 
understood, nor, to my 
knowledge, has it been 
discussed before. In my view, 
the difficulty we have in 
rendering subtle shapes can be 
traced to the fact that we are 
not consciously aware of the 
internal processes that 
underlie form perception. In 
order to copy a figure we first 
need to encode an accurate 
description of it and then use 
that encoding to instruct 
ourselves as to how to 
reproduce it. If the figure is 
simple, we can describe it to 
ourselves consciously—–for 
example, "a rectangle, twice as 
long as it is high." But if it is 
subtle and complex, such as the 
shape of a horse is, we cannot 
easily generate an accurate 
description of the shape that 
we could then use to guide us in 
copying it.

    We have roughly the same 
difficulty in attempting to copy 
a completely unfamiliar, novel 
shape that is not easily 
described, such as the one in 
the illustration at left. If this 
analysis of the problem is 
correct, again we would still 
have the problem of 
understanding why some 
people—–artists in particular—–
manage to overcome the 
difficulty. To simply say 
"practice" begs the question. It 
presupposes that artistic ability 
is entirely learned and thus 
fails to account for the fact that 
some children are good at 
artistic representation very 
early in their lives.

    The argument here is not that 
we have difficulty perceiving 
shapes, a process that I suggest 
in the next chapter is based on 
unconscious description. 
Rather it is that we have 
difficulty extracting or making 
such description conscious in 
order to guide us in copying 
certain shapes whose spatial 
relations are subtle.