Breaking a code

Art opens the mind. Paul MacCready, designer of the Gossamer Albatross, said that. But it is not only engineers like MacCready who make the discovery. A Russian lawyer named Wassily Kandinsky found it out on a fact-finding trip through the wilds of Siberia in 1889. He was studying the origins of peasant law when he was ushered into a cottage brilliantly painted - walls, floors, ceilings , furniture - with all sorts of designs and folk-tale illustrations as well as icons. He wrote in his Reminiscences that he felt as if he were in the midst of a painting himself.

The experience was not just an eye-opener. It set him on a whole new way of thinking, expanding his mental horizon far beyond its previous limits. He had always been attracted to art and had reveled in intense visual sensation without knowing quite what to do about it, even though he dabbled with paints. After this entry into the painted world, he gave up his legal career and moved to Munich to study painting. There he wrestled mightily with the problem of rendering the natural world. He became physically exhausted, and generally frustrated. He confided to a companion, Gabrielle Munter, ''Objects disturb me.''

There are some interesting theories of how people see physically, or perceive. This may account for some of his difficulty, but the root of the problem lay elsewhere. It dawned on him, after much thought about other kinds of painting and about music, that art is not an imitation of nature but is parallel to it.

Much to his delighted surprise, he found himself released not only from more mental limitations but also from the physical effects which had plagued him. Now he could paint freely and easily. More and more he abstracted the basic elements of what he wanted to paint, starting with line, reducing outline to notation. Color, with its emotional impact, became more symbolic and less localized in his work. He wanted to portray essence, the spiritual idea which he felt lay behind outward manifestation. His partly Mongolian background and Russian Orthodox Christianity may have influenced him in this direction.

And so he experimented. For many years he worked toward a completely nonobjective kind of painting in which objects disappeared as subject matter and emotions or states of thought replaced them. He produced a series of paintings he called ''Improvisations,'' in which he worked out his methods, and a concurrent series of ''Compositions,'' in which he made definitive statements.

Kandinsky is usually credited with painting the first abstract picture, which is slightly nonsensical, since all painting has an abstract component and is an abstraction from nature. There is some disagreement as to whether the term ought not to be nonobjective instead of ''abstract.'' Various art historians and critics have accepted Kandinsky's ''Improvisation 31 (Sea Battle)'' to be the departure point - partly because Kandinsky himself makes the claim.

But now E. A. Carmean, curator of 20th-century art at the National Gallery of Art in Washington, D.C., and others raise the question of just how improvised and nonobjective this ''Improvisation'' was. They are not the first to do so, but the fruits of their intensive study of ''Improvisation 31 (Sea Battle)'' have been published in a catalog that accompanied an exhibition last summer at the gallery which included this painting, preparatory sketches, and many of the rest of the series. The study shows the steps Kandinsky took in his evolution of painting.

Those were taken at a time of upheaval in Europe. Kandinsky, acutely conscious of what he described as spiritual disorder in the world, was painting apocalyptic visions veiled by his shorthand line and free color.

Carmean has analyzed this shorthand in ''Sea Battle'' thus: The vertical lines represent ship masts, curving areas of color stand for sails, and splashes mark the bow cutting through the blood-red sea. Handlike loops are waves or billowing smoke from cannon fire. A black blob in the lower right stands for what Kandinsky referred to as the dark side of spiritual life, ''a great, dead black spot.'' Toward the top of the picture are long oblong transparent shapes which may indicate risen souls. There are other iconographic symbols, but this much decodes the picture fairly well.

When later asked if he foresaw World War I at that time (1913), Kandinsky said no. Already he was painting parallel to, rather than in imitation of, the visible world. In any case, his work was prophetic, not only of the devastation and revival in Europe but in Europe's art as well.

Near the end of his life, after disappointing efforts to work in his homeland after the Revolution, and then after the Nazis' closure of the Bauhaus, where he taught, he came to Paris. By that time he was painting pictures such as ''Balance'' and ''Reciprocal Accord'' and moving toward more organic-looking forms dancing in space. No longer working parallel to events in the world, he had arrived at a joyous, sophisticatedly childlike expression of higher inner states.

He opened the way for current movements in Western art that deal with concepts rather than objects. Other painters of his day pioneered in this direction, too. But Paul MacCready's observations show how art opens the mind.