Paul Kos: Berkeley Art Museum.

Conceptual art seems to have acquired a reputation for humorless pedantics right from the start. Paul Kos's retrospective, which will travel to several venues around the country (including the Grey Art Gallery at New York University), goes a long way toward dispelling this misperception. For more than thirty years, Kos has been making Conceptual work that often is as funny as it is smart and good-looking. The exhibition's title, "Everything Matters," is key to understanding the videos, sculpture, and installations on view. (It comes from an aphorism attributed to Vaclav Havel In the West everything works, and nothing matters; in the East nothing works, and everything matters.) In Kos's elegant constructions, every detail is important. What matters most, however, is the viewer's participation; without it a number of pieces remain mute or incomplete.

Everything matters in other senses as well. In subtle ways, these are works about faith and conviction. Kos was born and raised in Rock Springs, Wyoming, into a family of Slovenian Catholics. The ritual and symbolism of his religious roots are reflected in works like Chartres Bleu, 1983-86, and Guadalupe Bell, 1989. In the former, twenty-seven video monitors are stacked to mimic the panes of a stained-glass window in Chartres cathedral. A twelve minute loop projected simultaneously on all twenty-seven screens simulates an entire day's light and darkness as it passes through a section of colored leaded glass. If a viewer merely glances at the piece, nothing seems to be happening. But if one spends even thirty seconds sitting in front of it, the changes in color and illumination are riveting. Guadalupe Bell also comes without instructions or explanation--it's just a large metal bell on a stand, from which a rope dangles invitingly. The reward for pulling the rope is not only the bell's loud, sonorous clang but a flash of light and the appearance of the Virgin of Guadalupe on the wall nearby. Her image, screened in light-sensitive pigment, glows for only an instant, then disappears again.

Bells, like time itself, are a recurring motif in Kos's work. One of the more droll pieces exploring both themes is also one of the most politically pointed. Just aMatter of Time, 1990, consists of fifteen cuckoo clocks, their hands removed. They stand fur the fifteen republics under Soviet domination during the cold-war period. Kos replaced the two weights that normally hang on the clocks' chains with a hammer and a sickle. Because these tools are of different size and weight from clock to clock, the instruments "cuckoo" at irregular intervals. Of course, the absence of hands makes it impossible to predict when that will take place.

A program of Kos's videos includes some of the pieces for which he became known during the heyday of Conceptual art. Works like Pilot Butte/Pilot Light, 1974, highlight the artist's connection to nature as well as his proclivity for artmaking as a kind of magic act. Using a piece of ice as a magnifying lens, Kos focuses sunlight on a pile of tinder until it ignites, and then he douses the flames with the melting ice. In a later sequence, the sun setting behind Pilot Butte (a landmark near Rock Springs) appears to set the mountain itself on fire. Over and over, a complicated mix of Zen-like humor, a deep love of nature, and the stubborn belief that even the simplest, smallest gesture is important distinguishes Kos from other artists of his generation. Everything works, and everything matters.