By ROBERTA SMITHMAY 15, 2015

VENICE — The world is a mass of intractable ills on which art must shed light. With oceans rising, climates warming, the income gap widening and human rights abuses of every imaginable kind occurring, the very future of the planet — its many futures — hangs in the balance. This is not the time for art as an object of contemplation or delight, much less a market commodity — certainly not in a public exhibition whose chief responsibility is to stimulate debate.

56th Venice Biennale: Pamela Rosenkranz’s pool of pink-tinged water at the Swiss Pavilion. Credit Casey Kelbaugh for The New York Times

That basically is the provocative but also confining message behind “All the World’s Futures,” the lopsided central exhibition at the sprawling 56th Venice Biennale, which runs through Nov. 22. Organized by Okwui Enwezor, a veteran curator of international undertakings like this, “All the World’s Futures” brings out into the open a central preoccupation of the moment, namely the belief that art is not doing its job unless it has loud and clear social concerns, a position whose popularity has made “social practice” the latest new thing to be taught in art schools.

In its single-mindedness “All the World’s Futures” echoes its 2013 predecessor, Massimiliano Gioni’s “The Encyclopedic Palace,” but from the opposite direction. More uplifting, Mr. Gioni’s effort opened modernist art history to all kinds of self-taught and outsider artists, expanding its origins to urgent expressions from around the world, somewhat at the cost of contemporary art. Mr. Enwezor is less interested in artistic urgency than in the urgent state of the world itself.

But like Mr. Gioni’s show, Mr. Enwezor’s effort is shifting the center of gravity away from the West and the art market. It proves once more that art — or something like it — is everywhere, widespread beyond imagining.

Regardless of whether you agree with his viewpoint or prefer considering art case by case, this position provides Mr. Enwezor’s show with clarity and purpose. There is something admirable and even heroic about its morality-based approach. In addition, it includes a fair amount of good, even great art, along with too much that is only well-intentioned. If it is not perfect, it goes off-message in redemptive ways, including artists whose work is not overtly political.

The entire project swirls around “Das Kapital,” Karl Marx’s critique of the effects of the Industrial Revolution and its reliance on exploitation of workers. Daily readings are featured in the arena designed by David Adjaye at the Central Pavilion of the Giardini, the public park that contains the art-filled national pavilions. Labor and work of all kinds is a recurring theme, whether we watch a gravestone of cast-concrete being made in Steve McQueen’s excellent video “Ashes”; enter into the strange world of Mika Rottenberg’s video installation “NoNoseKnows,” a mordant meditation on the rituals of cultured pearl production and utilitarian sneezing, or whiz past a big banner by Gulf Labor, a human rights collective organized to protect migrant workers in the United Arab Emirates. (I’m not sure the banner is art or even quasi-art, but I hope Gulf Labor’s labors succeed.)

Colonialism, perhaps the most extreme instance of the exploitation of labor, is a visible subtext, as is the show’s intent to reflect more completely than usual the diversity of the world’s population. It is full of women and of artists from outside the West, most prominently in Africa, Asia and the Middle East.

At times it feels as if Mr. Enwezor has included everything that interested him, with no thought to what the viewer can actually absorb. His show presents works in nearly every conceivable medium — including music, performance art and lengthy films and videos — by nearly 140 artists from 53 countries and several generations. Their efforts are crammed into the Giardini and the seemingly endless string of galleries that fill much of the medieval Arsenale, Venice’s former navy yard, a short distance away.

As with his 2002 Documenta XI exhibition, Mr. Enwezor’s proclivity for camera-based work bordering on documentary is apparent, evidenced here by Mr. McQueen’s work as well as Sonia Boyce’s “Exquisite Cacophony,” which records the brilliant improvisations of three vocal artists who mix the idioms of rap, jazz scat, Dadaist noise and gospel, and “Fara Fara,” a split-screen documentary by Carsten Höller and Mans Mansson about the vibrant music scene of Kinshasa, capital of the Democratic Republic of Congo.

And especially impressive are new hybrids of documentary, activism and expressive artistic power as seen in the disorienting films of Rosa Barba and Raha Raissnia and the multimedia installation of Lili Reynaud Dewar, a brilliant French artist and dancer who tackles issues of sexual orientation while paying tribute to Josephine Baker. Precedents for this kind of work include the word-and-music installations of the American artist-composer Charles Gaines.

The show is strengthened by art whose political impact lies primarily in the example of the makers themselves. Among the high points of the exhibition are the small, ebullient, if essentially Post-Impressionist landscapes from the 1950s through 1980s by the Egyptian painter Inji Efflatoun (1924-1989), a feminist pioneer who was imprisoned for being a Communist. The larger point is that the identity of who makes art matters terribly. Chris Ofili, Emily Kame Kngwarreye (1910-1986) and Kerry James Marshall are all represented by wonderful, even abstract paintings whose political thrust is less than obvious.

Mr. Enwezor’s talents as a master of theatrical presentation are often apparent. The Central Pavilion’s facade has been hung with enormous black and blue shroudlike cloths by the artist Oscar Murillo while just above is a pale neon piece by Glenn Ligon that announces “blues, blood, bruises.” Once inside, the first prominent piece is a large wall of old suitcases and trunks by the Italian artist Fabio Mauri (1926-2009), an obvious symbol of refugees and also the Holocaust, from 1993.

Things are even more obvious at the start of the Arsenale. Five neon pieces by Bruce Nauman, flashing with words like “eat,” “death,” “pain” and “pleasure,” cast their lurid light on an installation work by Adel Abdessemed: clusters of machetes stuck into the ground, suggesting bushes, explosions and stockpiled arms.

One of the best moments is an onslaught of sculpture by three artists made from found objects: Terry Adkins’s combinations of musical instruments shine, and Melvin Edwards’s small clenched welded-steel wall sculptures, made from bits of chain and tools, dominate, raising the troubling history of racial violence despite their beauty. Violence becomes more overt in the obsessive drawings of extravagantly vicious imaginary killing machines by the self-taught artist Abu Bakarr Mansaray.

Monica Bonvicini’s clusters of chain saws covered in polyurethane resembling black tar and hanging from the ceiling also use found objects, to achieve a kitschy obviousness. Mr. Edwards teaches Ms. Bonvicini a useful lesson in aesthetics: Subject matter must be empowered by form. It cannot be left literally twisting in the wind.

Among the rewards at the farthest reaches of the Arsenale is Emeka Ogboh’s “Song of the Germans (Deutschlandlied),” which surrounds the visitor with a recording of African refugees singing Germany’s national anthem in their mother tongues, resonating with the pain of bigotry past and present.

Mr. Enwezor’s extravaganza is an argument embedded in the curatorial equivalent of a food fight. Unlike other international biennials, Venice’s is surrounded by the random crossfire of the art selected by the individual countries for the national pavilions of which there are 89 arrayed in the Giardini, at the Arsenale and throughout the Venice itself.

A few pavilions stress formal purity, like the immense and stunning pool of pink-tinged water that Pamela Rosenkranz has inserted in the Swiss Pavilion — a fluid, girly version of Walter De Maria’s “Earth Room.” At the Austrian Pavilion Heimo Zobernig has leveled the floor and lowered the ceiling with planes of black, added a few white benches and planted an array of new trees in its small courtyard. It becomes a stark existential chapel in which thoughts of human folly contrast with the logic of nature.

Some artists have outdone themselves, like the performance/video eminence gris, Joan Jonas, who has filled the United States pavilion with the mysterious installation “They Come to Us Without a Word,” weaving a shifting tapestry of video, objects, music and ghost stories. Others, like Sarah Lucas, one of the few great artists of her notorious Y.B.A. (Young British Artist) generation, didn’t quite rise to the occasion, scattering the British Pavilion with intermittently pervy sculpture against dazzling marigold yellow walls.

Others succumbed to tired forms of festivalism, exemplified by Camille Norment’s expanses of broken glass in the Nordic Pavilion, which frame a more interesting sound piece; and Chihaur Shiota’s seductive presentation of two ancient fishing boats engulfed in a cloud of crisscrossing red yarn strung with hundreds of old keys, in the Japan Pavilion.

The national exhibitions featured works that would have enhanced Mr. Enwezor’s show, notably Hito Steyerl’s riveting parody of corporate malfeasance, a film propelled by an Internet dance sensation and projected in a gridded room redolent of the movie “Tron.” Visitors sat on deck chairs and lawn furniture, a scene that for me conjured the deck of the Titanic.

In the group show “Personne et les Autres” at the Belgium Pavilion, built during the reign of King Leopold II, the Belgian artist Vincent Meessen had invited a roster of artists from Africa and Europe to exhibit with him. But the gathering was dominated by his own documentary, “One. Two. Three.” It expands the history of the European avant-garde known as the Situationist International to include Congolese intellectuals, while also recounting the writing of a protest song that emerges tantalizingly as the film progresses.

The one artist who really engaged the world was Christoph Büchel representing Iceland. He orchestrated the conversion of a disused Roman Catholic church in Venice’s Cannaregio neighborhood into what became the only mosque in the historic part of the city, aimed at serving the many Muslims who commute to Venice each day to work. Mr. Büchel outfitted the interior with a convincing arrangement of prayer carpets, plaques and Qurans, and after weeks of touch-and-go negotiations with city officials he was allowed to stage the opening ceremony, complete with a sermon by an imam. But no sooner had this taken place than rumblings resumed, with the city threatening to forbid services being held there. It could function only as art, not for religion. Even so, the effort succeeded in shedding a harsh light on a failure of civic tolerance and understanding.