President Barack Obama awards painter Jack Whitten the 2015 National Medal of Arts during a ceremony in the White House, Sept. 22, 2016, in Washington. (Carolyn Kaster/AP)

CORRECTION: An earlier version of this article incorrectly reported that Whitten died Sunday. It also misattributed Katy Siegel’s quotation about the injustices Whitten faced to Kelly Baum and rendered the title of the exhibit incorrectly. It is “Odyssey: Jack Whitten Sculpture 1963-2016.”

Jack Whitten, the African American painter and sculptor who died Saturday at 78, was once given a tour of St. Catherine’s Monastery, at Mount Sinai. His guide, a young monk, led him down into the ossuary — “room after room of bones, of every monk who had served at St. Catherine’s.”

“This monk,” he told Jarrett Earnest of the Brooklyn Rail last year, “said, ‘I understand you are a professor.’ I said, ‘Yes sir, humbly so.’ And he said to me, ‘Here,’ pointing to the bones, ‘they are the professors and we are the students.’ ”

In departing this world, Whitten leaves behind not just bones but an extraordinary body of work which, after decades of neglect, is just beginning to receive its due. It has a lot to teach us.

Jack Whitten. "NY Battleground," 1967. (Copyright Jack Whitten/Hauser & Wirth)

In an art world lately bent on rediscovering neglected artists — not all of them deserving — Whitten is the real thing, an artist whose intelligence and ambition seeped into everything he did. A restless innovator who worked in two and three dimensions, he fought to give physical materials a concentrated spiritual charge. He wanted to merge ghostly abstraction with concrete immediacy, the sensuous world with tremors of the vast unseen.

It has been clear since 2013, when a show of abstract paintings Whitten made between 1971 and 1973 was mounted at the Rose Art Museum at Brandeis University, that his reputation was undergoing a massive reappraisal.

That reappraisal — which included a 2014 retrospective organized by the Museum of Contemporary Art San Diego — was fast gaining traction but still in low gear when he died.

The timing of Whitten’s passing seems especially bitter. “Odyssey: Jack Whitten Sculpture 1963-2016,” an exhibition of his most deeply personal work — carved and assembled sculptures that he declined to show until now, and in which he invested great reserves of creative energy and personal feeling — will open at the Baltimore Museum of Art in April before moving to the Metropolitan Museum of Art in New York.

Jack Whitte. “Anthropos #1.” 1972. Black and white mulberry, wild olive wood, linen twine, wire. (Genevieve Hanson/Copyright Jack Whitten)

“Black Monolith VII Du Bois Legacy: For W.E. Burghardt,” 2014. Acrylic on canvas. (John Berens/Copyright Jack Whitten; Hauser & Wirth)

“It’s so wrenchingly unfair,” said curator Katy Siegel, who organized the show with Kelly Baum of the Met. “It’s so hard to get over that wound of not getting what you deserved. Jack suffered from racism his whole life, but somehow he didn’t let it touch him or preoccupy him. ­His deep and profound under-recognition didn’t ruin his life. He felt it, but he went on to have the most marvelous life through sheer character and personality and force of will.”

Jack Whitten. Artist studio, 36 Lispenard St., New York, 1983. (Peter Bellamy/Copyright Jack Whitten; Courtesy Hauser & Wirth)

Whitten made the majority of the sculptures in his studio in Crete, where he spent long stretches of almost every year since 1969. His wife, Mary, is a Greek American; they have a daughter, Mirsini, who is his studio manager.

Siegel described Whitten as “one of the most wonderful people I’ve ever met. His greatness as an artist stems from who he was as a person.”

Whitten was born in Bessemer, Ala., the son of a seamstress and a coal miner who died when he was a child. In segregated Alabama, African Americans were allowed into art museums on only one day each year. Black children, according to Baum, were more often shown the steel mill and told to expect to end up there.

Whitten was a pre-med student with a range of intellectual interests when he went to hear Martin Luther King Jr. speak during the Montgomery Bus Boycott. They conversed, and Whitten joined King’s movement.

“When I met him in ’57,” he told Earnest, “I believed in him. I believed in the whole concept of nonviolence.”

But Whitten’s convictions were severely tested in early 1960. He went to Louisiana and was among the students who closed down Southern University and marched in downtown Baton Rouge.

“On that march we had to make a vow that whatever happened, we wouldn’t fight back. I witnessed evil. I saw hatred coming out of white people. They attacked us, threw s--- and piss on us. We made it all the way to the state capitol building as they were hitting us with sticks. I did it then, but I made a vow, I would never put myself in that position again. That march is what drove me out of the South. I took a Greyhound bus to New York City.”

Jack Whitten. "King's Wish (Martin Luther's Dream)," 1968. (Copyright Jack Whitten/Hauser & Wirth)

"April's Shark," 1974. Acrylic on canvas. (Copyright Jack Whitten/Hauser & Wirth)

Whitten enrolled at Cooper Union and, like many aspiring artists, fell under the spell of the charismatic abstract expressionist Willem de Kooning. He never ceased admiring de Kooning. But having absorbed the lessons of abstract expressionism, he knew he needed to get beyond them.

He had a genius, believes Siegel, for “summing up and moving on.”

“Where he went next,” she said, “went very much to who he was as a human being. He wasn’t interested in art for art’s sake. Instead, he developed a very expansive view of art’s role in understanding both the physical world and the world of the spirit and of emotion.”

"Dead Reckoning I," 1980. (Studio Museum/Hauser & Wirth)

Process — the “how” of making art rather than the “what” — became fundamental. To replace brushes, he made his own tools with which to apply paint. He experimented with an Afro comb, then a 12-foot-long brush of his own devising, and he separated pigment from acrylic medium, in one series scattering pigment over paper covered in clear acrylic.

He was also looking at African sculptures in the Metropolitan Museum, absorbing not only their forms — as European artists earlier in the 20th century had done — but their spiritual significance, and fusing this with his burgeoning interest in religions all over the world, and his African American heritage, including his upbringing in a fundamentalist Protestant church in the South.

Whitten’s work — once seen — needs no special pleading. The best of it all but forces consensus. Visually arresting, technically ambitious and personally urgent, it can feel like a missing link between the abstract expressionists of the postwar years and the minimalists and conceptualists of the ’70s and ’80s.

It enriches the abstract tradition in Western art with fresh political and spiritual content, and deepens our understanding of the background of major trends in recent African American art, from the material-loving, politically conscious abstractions of Mark Bradford to the politically and spiritually charged sculptures of Betye Saar and Vanessa German.

He is gone, but there remains so much of him still to discover.