Zen brush painters have a practice of painting freehand circles, sometimes as a warm-up for other painting, and sometimes as a painting in itself. We can do the same with whatever drawing or painting tool we are using.
Let us consider the difference between drawing circles with a compass and drawing (or painting) circles freehand.
When drawing a circle with a compass we begin by marking the center.
We place the point of the compass on the center dot, and turn the compass to draw the circle.
The starting point of the process is the visible mark of the center--the dot we marked, or at least the spot where the point of the compass is touching the paper.
The drawing of the circle begins with a visibly indicated center.
When we draw or paint circles freehand there is no visible center--the center, which is the 'principle' or origin of the circle, remains invisible, unseen.
The center must be intuited.
So, in the drawing of the circle freehand, one is guided by one's intuition of something not seen and not drawn. The center also remains unseen to the viewer of the drawing--yet the person viewing the drawing can, through looking at the drawing, come to the intuition of the center that the artist had and was guided by when making the drawing.
Drawing the circle freehand, then, is a good image for the saying of Dionysius : "We make assertions and denials of what is next to it, but never of it."
Our words and concepts and images are like the drawn, perceivable, circle. They are not the center--the center remains unperceived and unnamable--yet our perceptions and images can, like the drawn circle, awaken our intuition of the unseen center.
By beginning our art with the practice of drawing freehand circles we remind ourselves to awaken the intuition of the unseen and unseeable, and to let this intuition guide our art-making. And maybe our images can be occasions for awakening this intuition in those who see our work. Then our art will really be not about the drawing or painting at all, but 'about' (that is, 'around') what can never be painted or imaged or said.