To write about painting without discussing the spiritual would be absurd.
For me, most of the drive that creates toward intuition is both the harmonizing factor and the focus.
Painting is more of a verb than a noun, more like playing or composing for a musician. The painter both paints (plays) and composes at the same time. This always comes from the love of painting (tools, color, history, materials). It is not the illustration of an idea executed as some kind of joke with the most minimal dependancy on the medium.
The painter must be literate, and use it as a tool for gaining insight to his own intellectual endeavor. Painting should not be the illustration of an idea born of the intellectual endeavor.