It makes no difference whether a work is naturalistic or abstract; every visual expression follows the same fundamental laws. - Hans Hofmann

Each expression-medium has a life of its own. Regulated by certain laws, it can be mastered only by intuition during the act of creating. It is in the nature of the laws which govern every expression medium that two separate entities, related through empathy, always produce a higher third of a purely spiritual nature. This spiritual third manifests itself as a quality which carries emotional content. This quality is the opposite of illusion; it is the reality of the spirit.

Depth, in a pictorial, plastic sense, is not created by the arrangement of objects one after another toward a vanishing point, in the sense of the Renaissance perspective, but on the contrary (and in absolute denial of this doctrine) by the creation of forces in the sense of push and pull. Nor is depth created by tonal gradation (another doctrine of the academician which, at its culmination, degraded the use of color to a mere function of expressing dark and light).

as quoted in Jackson Pollock, Ellen G Landau, p. 259, as quoted in Jackson Pollock and Lee Krasner, Ines Janet Engelmann, Prestel Verlag Munich, 2007, p. 66