Since the 1960s, Ed Moses has been one of the central figures in the Los Angeles art scene. Moses' position results not from the originality of his art but precisely from its unoriginality --that is, its fully developed synthesis of already-existing ideas and approaches. Moses, after all, is a direct inheritor of abstract expressionism and minimalism; he fairly parades his membership in the "extended family" of abstract painting. Furthermore, he has worked his way through several styles, as the MOCA shows in a retrospective, covering nearly a half-century of his work.

In his thinking, Moses has embraced a wealth of ideas, the bulk of them borrowed. Part of his importance to Los Angeles art specifically, and American contemporary art in general, is his ability to turn ideas into formulas that are distinctive, even inimitable, and exemplary, almost didactic. Unlike other artists central to Los Angeles discourse, such as Ruscha and John Baldessari, Moses has not created a personal variant on an ism. Rather, he has exercised his sensibility on a surprisingly wide range of given isms, demonstrating the multitude of possibilities to whole generations of local, abstract painters.

The "real world" is not necessarily included in that range of possibilities, though imagery does prevail in Moses' earliest work.

The post-juvenilia with which the retrospective begins, for instance, depict shallow, schematized vistas filled with highly stylized structures, all rendered in a light, precise draughtsperson's line. The subsequent abstract expressionist canvases brim with bulbous, and rather lascivious shapes. Then flower images, exactingly rendered, are repeated obsessively throughout the 1960s. But references to the real world haven't made an appearance in Moses' work in almost thirty years, except for the relatively recent "Ror Shock and Wagu" series, in which tenebrous cartoon heads, tongues extended, pop up amid characteristic blots and smears.

The real-world influences Moses' art in other ways, however. Real material often has been part and parcel of his painting technique. The "Ill. Hegemann" series, for instance, whose zigzag formations are based on the patterns found on Navajo blankets and in the desert landscape, seem suspended in resin and hang unstretched but stiff on the wall. Many of the paintings that followed the "Hegemann" provide the same sense of brittle immediacy, fabricated as they are fabricated from Rhoplex and laminated tissue. Even when Moses returned to paint -- notably, acrylic paint, often heavily gessoed -- on canvas, he built up a surface so slick and so subtle that it comes across as industrial: blank, and durable as Linoleum.

What Moses achieved in this early 1970s work was the conflation of gestural painting with the perceptualism of Robert Irwin and other California artists associated with "light and space" and "finish-fetish" tendencies--tendencies which, like minimalism on the East Coast, had been regarded as essentially sculptural. Many of the perceptualists themselves began as painters; but they abandoned painting, or at least modified it and suppressed its gesturality, in favor of objects whose surfaces were uninflected, almost effaced. These objects were made of materials associated more with industrial fabrication --Fiberglass, Lucite, Rhoplex, cast acrylic--than with artistic creation. Such objects capitalized on the peculiar sensuosity that the unorthodox substances imparted to them. It was Moses' inspiration to reintroduce this industrial sheen to painting -- and to do so without compromising the very different haptic allure of painterly gesture.

The 1980s saw a universal return to traditional painting, once again encouraging Moses to wield a "loaded brush". The brush -- that is, one of the brushes -- he wielded to create the multipanel acrylics of 1982 brought back the brush of the 1970s: firm, emphatic, basically linear, leaving behind multiple striations on diagonal biases. But while the works of the 1970s rely almost entirely on this schema, Moses modified the schema when he created the 1982 panels. In these panels a welter of brush strokes imply increasingly forlorn remnants of a once-formidable pattern.

The retrospective is balanced and nearly thorough. However it leaves out works from 1977 to 1981, which does a disservice to our sense of Moses as a formal thinker who is also adventurous. It would be at least fascinating and probably revealing, to see how the painter transited between the two strongest groups of work in the whole show. The diagonal crosshatches of the mid-1970s and the painterly multipanel works of 1982, the high points in an exhibition full of oomph, are peculiarly powerful in their focus and their fusion of Moses' mental and manual energies.

Moses continued to marshal his energies. The paintings of the last decade, however, turn inward to some extent. The previous work, spontaneous as it is, was the result of intensive, self-conscious discipline. The exacting sense of balance and precision seen so clearly in the early images and the smaller drawings of the 1960s informed all of Moses' work up to the last ten years. The more recent paintings take this sense of balance for granted. In these works, some of the most gestural Moses has ever created, large strokes and blots flow and float with disconcerting randomness. That randomness is misleading -- Moses calculates his marks -- but the extravagance of the painterly incident maintains the fiction that the painter has impulsively set chaotic forces in motion.

What Moses has done in the work of the last decade is follow, not lead. His art of the 1960s, 1970s and early-1980s argued for Moses' maturity as a painter: It also testified to his impact on younger, West Coast artists, including a small group of painters devoted to repetitive linear patterns and/or monochromatic surfaces and a larger group that exploited industrial and technological processes to create work with a sense of amplified materiality.

The work since seems more a response to new indulgence in painting all over the world in the1980s. Again, though, Moses did not paint simple responses to neo-expressionist concepts. He responded to the new painterliness by indulging himself, for the first time since the bumptious abstract-expressionist works of the later-1950s, by going with the flow. By clearly not taking the lead in the new painting, Moses has lost some eminence as a pedagogical presence. But it's a trade that allows him to maintain a thoroughgoing and sustained level of experimentation.

Ed Moses is always experimenting, with forms, with objects, with ideas. This sometimes explosive, more often measured, but continuous restlessness gives Moses' work its pizzazz, and helps attract many artists to his work. We see this to an eye-popping extent in the retrospective, which, despite its possibly grievous gaps and the often-eruptive energy of the work itself, presents Moses' oeuvre as a coherent evolution.