There is a tension at the very heart of boxing which is becoming increasingly difficult to come to terms with. It is a sport which, uniquely, pulls onlookers one way and then the other and makes them perpetually uncertain about the ground beneath their feet. First it is perfectly safe and those who take part do so fully aware of the implications. Then it is fundamentally dangerous and it is the responsibility of any civilised society to step in and call a halt. Always one way and then the other.

This has been that kind of week. The charge towards acceptance and positivity was led by Wayne McCullough in a knowledgeable and sympathetic BBC Northern Ireland documentary which detailed his struggle to overturn a decision by the British Boxing Board of Control (BBBC) not to grant him a licence to fight here. McCullough's innate decency and humanity shone through in every frame and it was all but impossible not to empathise with his plight.

There seemed little room for equivocation. The boxer wanted to fight. There were very eminent doctors who said he was fit to fight. End of discussion.

It took only five days for that absolute certainty to crumble like so much dust in your hand. Just after 10 o'clock on Saturday night we happened to be in the car and as usual the radio was tuned to the crackly medium wave coverage from Radio Five Live. The main event was the bill of world championship boxing from Sheffield. The BBC's boxing coverage is predictably excellent but radio does the sport few favours.

Paul Ingle was fighting, defending his IBF featherweight title against the South African, Mbuelo Botile, and it was clear from a very early stage that he was coming off second best. The thrust of the commentary was relentless as Ingle lost round after round and seemed clearly disoriented and unable to defend himself in any meaningful way.

One chilling passage detailed the slow trickle of blood from Ingle's right nostril down over his upper lip and into his mouth. From there it was dripping out and on to his chin. The way in which this was relayed in such a matter-of-fact fashion only added to the grotesqueness of the entire episode. This did not sound like sporting entertainment in any meaningful sense of the term. This sounded like barbarism.

Ingle refused to buckle through all of this and the fight was only stopped at the start of the 12th round when he was knocked down for a second time. By then it was too late. A few hours later doctors in a nearby hospital operated to remove a blood clot from his brain. Just a year and a half ago Ingle came close to beating Naseem Hamed. Now his very life was in the balance. One way and then the other.

It is unlikely that Wayne McCullough was listening to the fight on the radio as we were. Maybe he was at ringside, but more likely he was watching it on that obscenely huge television we saw in his home in Las Vegas during the documentary just a few days before. Boxing has clearly been good to him. When he left Belfast to build a professional career in America, he had little more than the Olympic silver medal which was tucked into his back pocket.

McCullough had always said his boxing career was going to be about amassing as much material wealth as he could and getting out before he was 30. But there he was last week, approaching his 31st birthday, trying to explain away the presence of a cyst on his brain and justify his decision to keep on boxing on the grounds that he had missed at least two years because of injuries. The only person on whom the irony seemed to be lost was him.

The Paul Ingle fight must have made uncomfortable viewing for McCullough. He has been through his fair share of corrosive battles and, miraculously, has so far survived relatively unscathed. The worst of these was what was billed at the time as a reasonably straightforward defence against Jose Luis Bueno in Dublin. McCullough endured a terrible night of punishment, but the full horror was not apparent until he spoke last week about how close he now believes that he came to death during the fight.

THAT revelation was followed soon after by a proud reference to the fact that he is regarded by Ring magazine as having the best jaw in professional boxing. Again there was an unrecognised irony dripping from every word. If Wayne McCullough does not get out soon, then somewhere down along the line there may have to be some kind of pay-back.

But then maybe the cyst that was discovered in a routine scan before his fight here last October is benign and harmless. Maybe he has had it since birth and it poses absolutely no danger to him. Maybe he can keep fighting for just as long as he wants to and then he can get out with enough money to live comfortably for the rest of his life. Maybe. The thing is, he doesn't know. Not for sure. A few positive medical opinions, regardless of how eminent the sources, will now never make that doubt go away.

In boxing terms, McCullough has come face to face with his own mortality. He may never be able to go back to the old ways with the same swagger and the same unerring confidence in his own ability to come through safely to the other side.

For now, though, it looks like the BBBC will rescind their decision not to grant him a licence. Where McCullough goes from there remains to be seen, but there is every likelihood that the prospect of one or two more big pay-days will be impossible to resist. The sight of Paul Ingle reduced from a proud boxer with an indomitable spirit to a broken man crying as he slumped over the ropes at the side of Sheffield boxing ring probably won't affect Wayne's thinking one way or the other. But it should.