It surfaced in the 1980s when the prisoner Nelson Mandela craved a subject for connecting with the stony officer in charge of the maximum-security wing at Pollsmoor.

It surfaced in the early 1990s when Mandela and the African National Congress craved a great big carrot to show their collaborative intent in a post-apartheid South Africa.

It surfaced in 1994 as President Mandela came to power, a pivotal salve on the serial occasions when a nation of 43 million seemed bound for havoc.

And it reigned in Johannesburg on the winter Saturday of June 24, 1995, in possibly the best stadium to have inhabited in our lifetimes, when a nation of black and white brains had undergone such sweeping recalibration that it still seems near-miraculous.

This thing that kept materializing amid all the importance would be sport, a stabilizing force through a nation's urgent transformation. This would be sport, an entity always pegged as inconsequential in times of seriousness. This would be sport, so often egregious in its corruption and spite and lunacy.

It would be sport, a foremost tool for the most-admired person on the planet, the man the British parliamentarian Tony Benn once reasonably called "the president of humanity."

As president-of-humanity Nelson Mandela has fought his hospitalized way to a Thursday that doubles as his 95th birthday, we the sports-minded can reflect that nobody ever comprehended the comprehensive value of sport any better than this amazing individual. 

Nobody ever put it to better use.

As detailed in John Carlin's enviable, invaluable book "Playing The Enemy" (later retitled "Invictus" after it inspired the Morgan Freeman movie), it did figure that Mandela would think of sport. In his youth he had been a heavyweight boxer. All along he felt justly proud of his physique. While in prison for 27 years, Mandela would run in place in the tight cell of Robben Island (which retains its soccer pitch even in museum mode) or in smallish laps on the mainland prison, at Pollsmoor near Cape Town. Even after the untold strain of prison until his release in February 1990 at 71, he had the fitness of those two decades younger.

This giant beast sport had such rangy power, in Mandela's lucid thinking, that it extended even to a game he had spent his life ignoring and loathing.

Rugby long had carved a towering symbol of apartheid to oppressed South African blacks. The flags at the matches, the anthem sung at matches, the green jersey, the Springbok mascot -- in biology, a brown and white antelope-gazelle -- all connoted the vile, unearned privilege that had become an embarrassment on the planet. Understandably, South African blacks rooted against South African rugby.

Simultaneously, South African whites valued deeply South African rugby, while the galled outside world had stopped playing rugby with South Africa. To restore this treasured international rugby, the world would need the nod from South African blacks, especially the African National Congress.

As the rare black man who had played rugby, the ANC's Arnold Stofile, said of rugby, "This is not politics. It is not ideology. It is something much more powerful and primal, and personal." And as Mandela said, "Up to now rugby has been the application of apartheid in the sports field. But now things are changing. We must use sport for the purpose of nation-building and promoting all the ideas which we think will lead to peace and stability in the country."

A bunch of muscled gentlemen grinding and slamming against each other: It mattered greatly.

Springboks and Bafana Bafana visited the Nelson Mandela Foundation in 2008. (Getty Images)

So even as the white government of the early 1990s kept a repugnant inaction while right-wing violence afflicted black townships, the ANC kept a firm trust of Mandela's concept that to boil in resentment would harm mostly those doing the resenting. International rugby matches returned, sating what Stofile called "a sports-mad country whose main source of pride regarding the rest of the world was its sports prowess." With the guidance of Mandela and another former rugby player, Steve Tshwete, the ANC steeled even after fans dragged out the insulting old flag and anthem and shirt in 1992 during South Africa's first international match in 11 years. It persevered even to endorse in 1993 a daydream unthinkable even five years prior, a 1995 World Cup in South Africa. It trusted Mandela's view of sport to win the trust of sport-centric Afrikaners, to help white South Africa shuck pariah-hood and rejoin the human race.

As Carlin wrote, "The idea of using rugby as an inducement for the Afrikaners to board the democracy train could not have been more in keeping with the approach [Mandela] had rehearsed in prison, most obviously with Major van Sittert ..."

Van Sittert had been the stony prison officer.

Mandela had startled him by studying rugby, following rugby, then conversing about rugby.

It had helped Mandela negotiate a hot plate for his cell.

Even after he became a democratically elected president in April 1994, Mandela persisted riding sport on its wide artery into human hearts -- in this case, those of Afrikaners. Merely two months into presidency, he invited Francois Pienaar, the 26-year-old, 6-foot-4, 240-pound team captain, to a meeting. He argued to save the Springbok mascot because he knew it held meaning even as that meaning once helped mean 27 years of prison for him. As the players prepared for the World Cup on the gorgeous southwestern edge of the country, Mandela descended in a helicopter to surprise them, greet them, tell them, "You now have the opportunity of serving South Africa and uniting our people ... Just remember, all of us, black and white, are behind you."

That might have seemed specious except for the evidence congealing from Durban to Cape Town and back up to Pretoria. Speciousness was dissolving, and in the run-up through the World Cup, black fans would turn up at curbsides to cheer the team as it went by. White players learned to sing the black national anthem, "Nkosi Sikelele," in the Xhosa language, an inspired idea of the team's general manager, Morne du Plessis. Black prisoners cheered the team on a visit to -- get this -- Robben Island, where black prisoners once lustily cheered that team's foreign opponents. A white newspaper, Cape Town's Argus, blared the headline, "Viva the Boks," aware that "viva" long had been a cry of black protest. Black citizens beheld a team with 25 white players out of 26, a team they once disdained to the cores of their beings, and lend it an affectionate name, AmaBokoBoko.

All of this merged into the once-unimaginable, almost-inconceivable scenes from that June 24 at Ellis Park. For the final against mighty New Zealand, the president once imprisoned turned up wearing a former emblem of his imprisonment, the green Springboks jersey. He visited the locker room in Pienaar's No. 6, of which Pienaar told Carlin, "There are no words to describe the emotions that ran through my body." He walked out to the pitch in the green to a predominantly white crowd chanting, "Nelson! Nelson!" He heard the crowd sing along with a black man, Tokyo Sexwale, to "Shosholoza," an old Soweto staple that had become a fresh hit. And a president who still did not know all the rules felt overpowering tension while sitting through the overtime of South Africa's 15-12 upset.

"For decades," Carlin wrote, "Mandela had stood for everything white South Africans most feared, and the Springboks jersey had been the symbol, for even longer, of everything black South Africans most hated. Now, before the eyes of the whole of South Africa, and much of the world, the two negative symbols had merged to create a new one that was positive, constructive and good." Mandela gave the trophy to Pienaar: "Thank you very much for what you have done for our country." Pienaar took the trophy: "No, Mr. President, thank you for what you have done for our country."

A man of incalculable strength and unconquerable forgiveness had ushered an unwieldy country to a towering moment that had come with unfathomable speed in an unmanageable world.

Then again, that's sport for you. Sometimes you think it's trivial. Sometimes you think it's gigantic.