People seem finally bored of pronouncing that painting is dead: It is embarrassing when so many vital, original painters keep turning up. The new line, however, is that sculpture is in trouble, and this is an argument that’s harder to refute.

The problem for sculpture is that, when people first tried out the “painting is dead” gambit, anything that hastened the demise of the handcrafted two-dimensional image got labeled “new sculpture.” Sculpture could be anything a self-declared sculptor decided, so long as he could justify his activities in terms of movement in time and space.

What lost out in this new definition of sculpture were the time-honored means of working plastically, in the round: modeling, carving, or joining things together. The latter – welding, assemblage – fared best in this new deal, because it is related to collage, the 20th-century technique par excellence.

There can be no denying that determined reinventors within the traditions of carving and modeling are thin on the ground. A trip round the galleries this month, however, should give rise to optimism.

Louise Bourgeois merrily makes little distinction between old forms and new, as befits an artist who discovered the primordial in lived personal experience.

Although the nonagenarian’s latest show at Cheim & Read is dominated by several series of drawing, it is named for a major new sculptural work, “The Reticent Child,” which combines elements of sewing, carving, assemblage, and installation. The piece, first presented at the Freud Museum in Vienna last year, consists of six sculptural elements installed on an aluminum table approximately 9 feet long. The figures, variously sewn or carved, are placed in front of a concave mirror, which captures and distorts their reflections.

This mirror plays so prominent a role that it is hard to suppress the suspicion that it is a kind of Lacanian Trojan Horse, sent by the French-born sculptor to penetrate the Berggstrasse citadel. When I saw the piece, I was intrigued by a set of puncture points in the glass; naturally I looked at my own distorted reflection, then got back to examining the sculptural forms. Only when I studied the catalog at home did the fine photographs (by Christopher Burke) disclose the integral function of these distorting devices.

I suppose a child, stooping parent, or very short person would more readily gain a vantage point that would allow the figurines to be seen in relation to their distorted reflections. Magically and suggestively, the expressively forlorn, fragile, sewn dolls become, in their mirror selves, monumental Venuses de Willendorf. The writhing mother, giving birth to the eponymous reticent child, switches back and forth, in the illusory screen, between skeletal and bulging doppelgangers: One moment she’s a Giacometti, the next – bulbous and with gaping holes – a Henry Moore.

The material quality of a Bourgeois sculpture is ambiguous. Her images are usually fabricated for her by seamstresses or artisanal carvers; they are not forms discovered in the making. Yet the value, the meaning of the work is enormously extended by material choices: sewnness or carvedness carry preverbal symbolic weight. The alternation between soft and hard, malleable and static, build up to a complex narrative, linear and yet at the same time circular, of birth and motherhood.

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British-born Jon Isherwood fuses timeless technique and the high-tech in a show of immensely satisfying sculpture. His carvings have the undemonstrative, clean, calm control of a Medieval mason, but the forms have the unmistakably voluptuous complexity of computer-generated images, at once organic and geometric. His curves and folds share digital origins with Frank Gehry’s, though the architectural resonances of his stacked cobras are less with postmodernism than the sacred fractals of Gaudi and with Hindu stupas. There are points of formal and conceptual connection with a number of contemporary British sculptors – Tony Cragg, Stephen Cox, Peter Randall-Page – but there can be no question that Mr. Isherwood is an original.

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William King is one of the great mavericks of American sculpture. He is best known for stick figures welded in a folksy, jocular idiom, though he is protean in his embrace of mediums and techniques. To aficionados, however, his early work from the 1950s and 1960s retains a charm that is typically diluted in his oversized, publicly sited metal pieces: When he still worked in wood, there was an insouciance and warmth lost in the relatively impersonal mature work.

Next year Sanford Schwartz will curate a museum loan exhibition of early King. In anticipation, Alexandre is presenting a group of 35 portrait busts in ceramic, a little-known aspect of his work. Like their recent exhibition of Lois Dodd’s paintings on roofing tiles, the gallery’s audacious installation has paid off.

The figures are placed literally cheek by jowl on two giant pedestals; the effect recalls Alex Katz’s party scene cutouts on ping-pong tables. Mr. King’s handling of material is pitch perfect: A sense of the spontaneous is preserved in the manipulation of the clay, while an ethereal otherness creeps in with the glaze.

Some heads are self-portraits; some portraits of bohemian peers like Marisol, whose beauty and character survive his satiric pummeling. Other invented heads are out-and-out gargoyles. In all, this is a bestiary that revels in kindhearted grotesque.

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The Brazilian Saint Clair Cemin is both a carver and a modeler of consummate skill. His vision is at once classical and primitive, with a gently surreal, subversive edge: a familiar brew in Latin American art, but something in the handling, if not the strategy, gives this riotous, good-humored show freshness and verve, however.

The show is dominated by classical carved heads and sinuous totem poles. A mass of modeled heads on the floor in the back room, however, evokes a different mood, looking like the contents of a neglected museum storeroom. While expressivity animates individual pieces, which look variously like Roman figurines and Carpeaux maquettes, the overall impression is a melancholy one, of fragments shored against our ruin.