Why this shape and not another?

IN Virginia Woolf's novel ``Mrs. Dalloway'' ``a sense of proportion'' is the touchstone of sanity. In Ellsworth Kelly's paintings it is the essence of form. Considered to be one of the most influential of the modern painters, Kelly diverged from the Abstract Expressionist movement that dominated from the 1940s and '50s to become a radical exponent of ``hard edge'' painting. Kelly's unframed, abstractly shaped canvases resist an easy definition as either painting or sculpture and are also reluctant to yield to conventional interpretations of meaning.

The artist was fascinated by the relationship between colors and the relationship between form and color, and most of his works, like ``Diagonal with Curve III,'' are devoid of any direct representational allusions. They appear to exist solely on an abstract plane. It is surprising that a work as formalist in its conception and remote in its relevance is capable of making such an impact. Part of the reason lies in its proportions.

It is instructive to consider just why this painting ``works.'' Because of its dramatic shape, which the uninterrupted slash of solid black seems to accentuate, the painting seems to demand this type of analysis. Why, for example, the arc above the straight line, the difference in length between the lower left and the upper right borders, the juxtaposition of exactly those angles?

The fact that these questions are unanswerable, even by Kelly, I suspect, illustrates the extent to which art, even at its most abstract, is an intuitive process based on intuitive decisions. A difference between an artist such as Kelly and the rest of us is his heightened perception of the abstract form underlying appearances, just as a biologist is aware of the skeletal structure of organisms or an engineer of the structure of a building. The result of this vision is a perfect sense of proportion.

The next logical question when confronting a work of art such as this is upon what is the artist's intuition based? Why this shape and not another? From what did he derive his idea?

I think it is obvious that consciously or unconsciously Kelly took the inspiration for this work from flight. Conjuring up natural and technological images of flight, the painting floats like a feather, flaps like a wing, soars like a projectile. Despite its stationary state it is filled with the tension of an object that strains to be in motion, and one senses that the guiding principle behind its design was aerodynamic.

Part of the function of a work of art is to evoke, to have this kind of resonance. This means its effect should extend beyond the visible image and stimulate in the viewer's mind associations and connections that give it meaning.

This painting not only suggests flight distilled to its essential form but also the relationship between art and space. Just as flight cannot exist except in space, art can exist only in space. It is space that cradles it and frames it, that makes possible the definition of its form.

By giving his canvases sculptural shapes and leaving them unframed, Kelly underscores the symbiotic relationship between art and space whereby each not only hosts but also transforms the other. According to Kelly's vision space is the precondition of art just as it is of flight, and one can find in the trajectory of this seemingly simple diagonal curve a metaphor for artistic creation.