AT the San Francisco Museum Of Modern Art (SFMOMA), they’re celebrating the work of the incorrigible Richard Tuttle by showing more than four decades of his work. The American Tuttle has been an artist since the early ’60s, and is always experimental and thought-provoking. What makes this show particularly delightful is that Tuttle was involved in setting it up. Tuttle, of whom relatively little is known in India, is extraordinary for what he does with the givens, how he consciously harnesses the basic principles of physics—light, space and optics—into art. A series of stuck-on-the-wall works, from the late 1970s, is just one case in point. A series of paper cut-outs are folded, brushed over with paint and pasted on the wall. But these works don’t cling to the surface as a mechanical, factory-made object might. As a result, the odd corner peels off or just hangs off the rest of the surface, making the work neither a flat painting, nor a completely three-dimensional sculpture. It’s in the middle, resisting and challenging the idea of niches. Now and then, Tuttle even breaks through these borders, using colours to traverse the solid wall above and around. His work then spills over, lapping up the space around it. A similar sense of assertion is unleashed by his wire works, (again, from the early ’70s), where he draws, in his quivering hand, a line or shape on the wall. Then, a thin wire is coaxed over the line, with startling results. Shadows overlay the slight lines and metal crouches above. It works like a dance, the next step a surprise. Expanding the idea of boundless space, Tuttle pays sensuous homage to the forgotten parts of a room. Here too, he recalls the space using his art, but his eye (and that of the viewer) wanders to the marginalised edges. He works with the bottom edges of the walls and corners, wittily tickling our untrained senses. A small, some three-inch piece of white cotton is twisted into a wick-like shape and nailed onto an inconspicuous part of the wall. When you see it, it’s a surprise. But it is not a small sliver of wall you see. It’s the point where the entire room appears to converge. The largeness is overwhelming. Are some aspects of Tuttle’s art so personal that they will end with him, to be shown in the future only as imitations? In some aspects, at least, they are like installations that can be mimicked, but they lack authenticity in the absence of their author. This mortality of art is challenging to the viewer because it suggests that, despite being physical objects and being shown in a museum, art pieces could be as mortal as their creator. It takes away that inherent sense of ‘foreverness’ associated with most art forms today. In fact, it denies the museum a second handling of itself in the absence of Tuttle. It is challenging to the viewer in other ways too. Trained or untrained, intuition forces us to look at artwork as classified types. Tuttle disallows that. He forces us to see art as an idea, not a type. That is probably the foremost realisation about art as it stands today.