William Kentridge at MoMA, New York

‘SelfPortrait’, charcoal on paper, from 1998

If irony is the default posture of our time, then William Kentridge must have slouched into the present from some more earnest era. His mode is tragic, or at least melancholy, with a touch of the absurd. A white South African who abhorred the old system and has been disappointed with the new, he doesn’t crusade, yet he seethes with outraged morality. “I am interested in a political art,” he has said, “an art of ambiguity, contradiction, uncompleted gestures and uncertain endings. An art (and a politics) in which optimism is kept in check and nihilism at bay.” That wavering line – between memory and oblivion, hope and despair – forms the literal basis of Kentridge’s art.

He draws, erases and redraws to make the savage and lyrical short films he calls “Drawings for Projection”. He records each minute metamorphosis as a frame. The laborious process leaves him with a final drawing – sooty, smudged and laced with spectral lines – and a filmed record of all its vanished predecessors. As with the anguished history he confronts, the last version coexists with all previous drafts.

In the Museum of Modern Art’s enthralling Kentridge retrospective, drawings and prints hang in interstitial spaces like posters in a screening room vestibule. Everything in a frame feels inert, a by-product of the silent movies that are the exhibition’s main event. Projected on to gallery walls and partnered with soundtracks that shuffle Monteverdi, Ellington, Dvorak and African choruses, these miniature epics narrate the intertwined stories of three mute and lonely characters.

Soho Eckstein, an amply jowled industrialist in a pinstriped suit, stands in for white South Africa’s rapaciousness and, also, belatedly, for its conscience. Egotistical and overbearing, Eckstein neglects his sensual, shallow wife, who has turned for sex and comfort to Felix Teitelbaum. We usually see Teitelbaum from the back, naked and submerged in tides of anxiety, longing and guilt. Vulnerable and passive, he incarnates gutlessness in a time of turmoil. Kentridge has said that it was only well after he had invented these unhappy antagonists that he recognised elements of himself in both.

They sprang from the knowledge of failure. Kentridge, now 54, spent his youth pursuing an assortment of careers. He tried painting, but wrestled with colour. He went to Paris to act, but discovered the limits of his talent. He launched a film career, which fizzled out. Finally, he found in animation a métier that combined drama, draughtsmanship, music and psychology.

‘Seated Couple (Back to Back)’ by William Kentridge, charcoal on paper, 1998

His first film, Johannesburg, 2nd Greatest City After Paris, is set in a post-industrial landscape of bare hills and idle mines. Soho buys up half of Johannesburg with the sweep of an arm. Felix soaks in the bath, dreaming of Mrs Eckstein and indulging his many apprehensions. Both idylls end abruptly. By the end of the seven-minute instalment, the proletarian masses stand triumphant over Soho’s domain, as he and Felix, each equipped with a giant club, beat each other senseless in a Goya-esque duel to the death.

Kentridge’s cast of alter egos allows him to explore the meaning of personal attachments and the larger story of culpability, remorse and possible redemption. South Africa’s trauma and its moral reckoning hang over even Kentridge’s most intimate work, though it’s not always clear whether history is a metaphor for personal conscience or the other way around.

The arduousness of his technique comes across as a form of expiation. While many artists simply dream up ideas and call in fabricators to execute them, he subjects his handiwork to constant revision. The eraser becomes a tool for blotting out sin, and his toil is a form of atonement. In the catalogue, Kentridge explains: “Using hired hands to do the actual labour has been tainted [in South Africa], made impossible by the image of the white overseer in his shorts in the shade, watching a gang of labourers doing the work.”

Kentridge’s art of the late 1990s soaked up the fallout from the Truth and Reconciliation Commission, which officially forgave all who owned up to torturing, killing, or otherwise oppressing their countrymen. To Kentridge, this constituted a cheap and obscene ritual: he raged at the perfunctory confessions of heinous crimes followed by grudging absolution. Ubu Tells the Truth, his animated response to the commission, inscribes Kentridge’s frustration. The figure of Ubu – an obese embodiment of the white power apparatus – capers about in diabolical metamorphosis, slithering into a skeleton’s head or a camera tripod with humanoid legs.

Stark interrogations alternate with footage of protest and massacre. The sinister tripod uses its spindly legs to tuck a bomb under a body, gather the pieces, and blow it up again and again – something the South African security forces actually did to those whom they wanted, not just dead, but disappeared.

In recent years, Kentridge has become more introverted and oblique. One large room at MoMA hums with concurrent films of the artist in his studio, handcrafting illusions like a birthday-party magician. We see his hands conjuring lines on a sheet of paper, or reassembling a shredded self-portrait. But if the content has changed, his preoccupations have not. From the doppelgängers Soho and Felix, through the shape-shifting Ubu and his exploded victims, Kentridge has remained fascinated with the dehumanising fragmentation of the self.

Lately, he has immersed himself in the The Nose, a Gogol short story and Shostakovich opera that he is directing at the Metropolitan Opera. A civil servant awakes to find his nose has vanished; it later turns up in a more luxuriant life, and with a more promising fate, than its owner could have provided. Kentridge turns the proboscis into a jazzy adventurer, dashing through sequences of constructivist collage. If a hoary Russian tale can satisfy a contemporary South African connoisseur of the absurd, it’s because disembodiment is universal: to mistake a man for his nose is not so different from valuing a person by the colour of her skin.

The magic of Kentridge’s art comes partly from the way he expresses metaphoric concepts with literary vividness. Social change comes in a flood of blue pencil strokes; fat cattle waste away; cities dismantle themselves. Compressed into a list, such gestures seem heavy-handed, but Kentridge makes a virtue of weight: Ubu, Soho, Felix and the artist all share a hangdog bulk, and these thick-limbed heroes of extravagant appetites endow their little plotless stories with the heft of an ancient saga, a tale of error and grace.

‘William Kentridge: Five Themes’, MoMA, New York, to May 17. www.moma.org