“Don't Touch” is an unspoken warning in any art museum. Sometimes an institution might post a sign explaining to visitors why touching the art on view is bad — not just for the obvious catastrophic reasons, but because even oils from hands that appear to be clean can cause incremental damage. Mostly, though, visitors already know what they are (or, rather, aren't) supposed to do in art's presence. Touch is a privilege typically reserved for the artist who made the art, as well as its professional caretakers. In fact, “the artist's touch” has been a central value in Western art for hundreds of years. By the start of the 1960s, with the Abstract Expressionist generation of American painters riding high, it had even become something of a fetish. The loaded brush, the whiplash line, poured paint, the palette knife and sponge — signs of distinctive gestures mattered, almost like handwriting. De-mythologizing the artist's touch was left to Andy Warhol, who announced that he instead wanted to be a machine, and to Sol LeWitt and his idea-oriented cohort of Conceptual artists. They pulled the plug for good. Enter Franz West, the impish Viennese artist whose compelling retrospective is at the Los Angeles County Museum of Art. Born in 1947, West is a generation younger than Warhol and LeWitt. The fetish for the artist's touch having been retired just before he arrived on the scene, he took the next step. In the mid-1970s, West handed things over to the audience. Literally. Wrapping pieces of wood and cardboard and lengths of wire with gauze, coating it in plaster or papier mâché and painting the whole thing white, West made sculptures that the audience was meant to pick up, manipulate, examine at close range, hang on an arm or around the neck, or even stick one's face into. The shapes are abstract. But often, part of the sculpture suggests a handle — a direct visual invitation to audience participation. Silently it says, "Touch me, hold me". Other shapes appear designed to fit around the neck, under the arm or on other embraceable parts of the body. Or, they echo bodily orifices. (Can a sculpture have a belly button?) A glass bottle at the end of a long stick, both embedded in lumpy papier mâché, looks like a ritual implement meant to be passed around in some primitive religious ceremony. These materials also evoke the damaged condition art holds in contemporary life. Like a cast made for a broken limb, white plaster and gauze result in sculptures bound in a medical dressing. West calls these sculptures “Passstücke” -- originally translated as “fitting pieces” (passende Stücke) but now referred to as “adaptives.” In biology, adaptation is a structure or form modified to fit a changing environment. West's touch-me sculptures attempted the same for art's new circumstance. The Austrian sculptor didn't begin to study art seriously until he was 26, which might explain two distinctive features of his work. First, West's expressive take on things is jaundiced and mature, snarky but sophisticated — Benny Hill with brains. And second, like an adolescent prankster with an old soul, its tone deepens and becomes more resonant over the next three decades, even though the die was cast right from the start.