Deborah Butterfield at Paule Anglim

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  Deborah Butterfield's "Kamoe" (2009) is bronze cast from scavenged branches.
  Credit: Gallery Paule Anglim

Montana sculptor Deborah Butterfield produces good work so consistently that she almost makes me want to see her stumble, just to know whether I could catch her at it.

The recent work at Paule Anglim continues Butterfield's endless fascination with horses as subjects or pretexts for sculpture.

Butterfield keeps horses and rides them as frequently as most people drive.

Her work owes some of its power to her bodily connection with its subject matter. She has not only observed horses in every phase of their lives, she has moved with them and against them, felt their individual energies and temperaments.

The two main currents of modern sculpture - construction and casting - converge in her work, magnificently in the bronze "Kamoe" (2009).

Like many of her pieces, this one appears to be composed of sticks of deadwood. She did in fact assemble from scavenged branches the original from which the bronze was cast in sections. Brilliantly handled chasing and patina have given the metal a likeness to wood that only a touch would truly dispel.

At a distance, a viewer may see this portrait of a recumbent horse as a pile of sticks, with a suggestion of mountain horizon in its upper profile.

Closer, the play of found forms against the rough sketch of equine anatomy - a constant in Butterfield's work - comes into focus. Then it falls out of focus into sculptural abstraction, then sharpens again in new ways, with changes in viewing angle.

Complicating the bafflement that Butterfield's constructive brilliance presents are the shifts in scale from one work to another. In small pieces in salvaged copper or steel, she tests the capacity of an available form to sum up a contour, a posture, a limb, as if seeking the limits of descriptive concision.

Abstraction has its Moment: Sacramento painter Joan Moment took on a deceptive difficulty some years ago when she began to use open circles as key forms in her paintings. Several works on view at Limn exemplify the problem.

Tales of ancient artists competing to produce perfect circles freehand give the form mythic roots. But I wonder whether rings left by a coffee cup or a paint container may have begun Moment's reckoning with the circle.

In any case, it can look rote when repeated.

In "Mapping the Stars II" (2008), Moment shows that by proliferating circles of different sizes, connecting them in various ways - including by title - she can produce a painting as abstract as you please, humming with echoes of concepts and images, that haunting of our vague grasp of science's influence on culture at large.

We know that astronomy has mapped the heavens, that molecular biology and physics have mapped the microworlds of life. But most of us will remain adrift in this foggy awareness, however we may encounter its consequences. Think of climate change, threats to public health, the militarizing of space.

Moment's paintings correspond not to realities, but to mental postures in which we face ultimate things. We may have only the crudest models of ultimate realities, her art suggests, yet find ourselves equipped with needful intuitions of feeling that hard science precludes.

Limn has paired Moment's show with a selection of three other very different, but equally authoritative, abstractionists: Sid Garrison, Thierry Feuz and Kim Squaglia.

Thorsten Brinkmann gets it done: Do not overlook the centerpiece of Catharine Clark's group show "Remix": German artist Thorsten Brinkmann's video "Gut Ding will es so" (2003). It ends today.

Extending a line of task-oriented performance begun by Vito Acconci, Bruce Nauman and others in the late '60s, Brinkmann puts himself through - literally in a few cases - obstacles or challenges that various objects pose.

In one episode, he breaststrokes across the camera field, swimming effortfully through air, prone on a dolly. In another, he threads himself through the rigid arms of a chair.

A satire of fraught relations between function and desire, of artists' determination, perhaps of human will itself, his video amuses and amazes without stint or comment.

Deborah Butterfield: Sculpture. Through Aug. 29. Gallery Paule Anglim, 14 Geary St., San Francisco. (415) 433-2710. www.gallerypauleanglim.com.

Joan Moment: Paintings. Summer Abstractions: Works in several media by three artists. Through Sept. 12. Limn Gallery, 292 Townsend St., San Francisco. (415) 977-1300. limnartgallery.com.

Remix: Works in various media by six artists. Ends today. Catharine Clark Gallery, 150 Minna St., San Francisco. (415) 399-1439. www.cclarkgallery.com.