Oscar Wilde wrote in The Picture of Dorian Gray, “All art is at once surface and symbol”.
The actual layer of paint on canvas or board is the surface, which fact can never be ignored. The mere marks, lines, brushstrokes that make up the surface are also symbols. They may, if only purely abstract and formal in presentation, still symbolize to the eye, mind, or heart ideas and meanings only realized by the subconscious yearnings for archetypes. Archetypes begin as personal and present themselves to the collective, the individual to the common.
If those marks begin to represent something recognizable, regardless of subject, they still symbolize the object, never actually becoming it. A paradox lies in the fact that no matter how exact an object is represented, it is still an illusionistic symbol of something else.
A good work should be surface and symbol, cognitive and spiritual, freedom and restraint.
These are the things I think about when I paint.