To make the following point clear, let’s imagine drawing a three – dimensional sphere, in cross – hatching, using only the light and dark of the pencil. Of course, there is the typical fight between the dark and the light values, but there is another factor. The length of the lines used is very important, because if there was no end to the line used to draw the shadow, the line would extend across the whole drawing, leaving no possibility for a highlight in the drawing, where the light hits the object being drawn. The same happens if the line had no length, because then it is impossible to draw a shadow on an object without putting down a line or a dot (which is basically a plain made up of an infinite amount of lines running in every which direction) on the paper.
So, the drawing is not only a contest between the lightness and darkness of the line, but also of the size of these lines. The same way, life is also a contest of not only good and evil, but also of the ever – changing versus the ever – constant.