DRAWING SUBTLE SHAPES 
Recreating a subtle shape from 
memory is not  easy.  The 
unfamiliarity of the shape and 
its subtle spatial relations 
make it difficult to copy.

A second difficulty in drawing 
accurately even when copying 
from actual objects or other 
pictures concerns the subtle 
spatial relations that 
constitute certain shapes. For 
example, suppose we attempt to 
sketch a horse or a picture of 
one. For most of us, this is 
difficult to do well, even if we 
take great pains with it. We 
realize when we look at our 
first attempt that it is not right, 
but, curiously, we do not 
necessarily know why it is 
misshapen. If we continue to 
revise the sketch, we can 
recognize when it is improved. 
By converting the task into one 
of correction through 
recognition, we may eventually 
achieve a satisfactory drawing, 
but few take the trouble to do 
so.