Anglicans aren't quite as big on saints as Catholics - and certainly don't approve of the more contemporary sort. But in Desmond Tutu, vanquisher of apartheid and spiritual head of the Rainbow Nation that modern South Africa aspires to be, they have their very own living saint. A living saint, it should be said, who bursts into his trademark and very unsaintly laugh - half a cackle, half a wheeze, with a high-pitched chuckle mixed in - at the very thought of a halo. A living, laughing saint who moreover, it was reported in 1999, was dying of prostate cancer but is today jumping around like a teenager. "When they heard upstairs," he says between guffaws of laughter, "that there was the prospect of my coming, they said: 'No, no, no, no. Keep him down there. We can't cope with him.'"
We've met at King's College, London, where Tutu is spending two months as a visiting professor in post-conflict societies. It's his Alma Mater. He studied in the UK in the 1960s, before returning to South Africa to rise through the ranks of Anglicanism, eventually becoming Archbishop of Cape Town from 1986 to 1995 - a thorn in the side of the white South African government but an international hero who was awarded the Nobel Peace Prize in 1984. As General Secretary of the South African Council of Churches (a position he held from 1978 to 1984), he was the one spokesman for black South Africans that the apartheid regime dared not silence or imprison. As has happened in other repressive societies around the globe, the churches became a conduit for a national movement of liberation. History shows that it was effective, but many at the time, and since, have suggested that Desmond Tutu was less a man of God than a political crusader.
Since he starts by asking me to join him in a prayer, and thereafter refers constantly to the Bible, I could have guessed at Tutu's reaction when I finally get round to putting this criticism to him. It - inevitably - first of all prompts a massive fit of hilarity. He sounds like Charles Penrose's Laughing Policeman. But then he becomes serious - almost angry. "I get a little sad when people say that," he says, "and ask people: 'Which Bible do you read?' When God delivers a bunch of slaves out of bondage, is that a political or religious act? Or I ask them to read Isaiah 58, the piece on fasting. God says, 'I don't want your fast. Your fast is a sham.' I always say when I quote this, 'this isn't Tutu speaking, this is the Bible.' So God says tells them 'I want you to feed the hungry and clothe the naked.' Jesus himself says you will not be judged on whether you prayed or went to church. Jesus said you will be judged on whether someone was hungry and you fed them, whether when you encountered someone naked you clothed them. What is shattering" - and here his sing-song voice becomes a whisper as he touches me on the arm and stares into my eyes - "is that he says if you do it to one of these you are doing it to me."
The room we are sitting in is one of the grandest at King's - high-ceilinged, ornate and lined with portraits of former deans, a reminder that the college was founded 175 years ago as a religious institution to counterbalance the more secular University College. The backdrop serves to make Tutu, now 72, look even tinier than he is (he is not much more than 5ft tall), while his café latte-coloured Arran jumper swamps him and adds to the sense of a man utterly out of context. The effect is rather like seeing the Pope dressed in a pinstriped suit.
The archbishop, though, is clearly feeling very much at home. He came here in 1962 - just two years after the Sharpeville massacre left 69 peaceful demonstrators dead - with his wife, Leah, and his four children, one boy and three girls (one of them, Mpho, is now ordained as a priest). As well as his studies at King's, he worked in parishes in Golders Green and then Bletchingley in Surrey. Few would have suspected what was to happen to their young curate, but by 1975 his reputation in South Africa was such that he was named the first black dean of Johannesburg Cathedral. The post in theory allowed him to live in a whites-only area, but he was having none of it and made the family home in Soweto. A year later, he was on the front line as 600 died in the township following protests about the forced use of Afrikaans in schools. His international reputation was growing.
"My title here at King's - visiting professor - sounds very erudite and impressive," he reflects, "but I think it is a brief to be nostalgic - to reminisce about the kinds of things that have happened in South Africa." He is, he admits, looking forward to the teaching the post will involve. "I really wanted to become a physician. I was admitted to medical school but didn't take up my place because my parents [his father, Zachariah, was a head teacher] didn't have the money to put me through. So I went to a government teacher training college. I enjoyed teaching. The whole question of my vocation came about through external pressures when the South African government introduced the Bantu Education Act that was designed to be a travesty of education for blacks. I felt I couldn't co-operate with this - but after that I didn't have too many options. So going to theological college and being ordained in 1960 was a soft touch, as it were."
There's a twinkle in his eye as he delivers the punch line. Tutu has the rare ability to switch mood within a sentence. It's especially rare in churchmen, not noted for their sense of humour about themselves or their calling. But that's what makes Tutu appeal beyond the pews to a wider, secular audience. The showman in him - a description used by the late Robert Runcie - seems to know just how far to push it in making himself - and by association his God - seem "normal" and therefore relevant. Try imagining Dr Rowan Williams or George Carey saying they'd only joined the priesthood because they didn't have any other choices; it's impossible. That Tutu gets away with it so effortlessly is just one of the benefits of being a living saint.
Another is that people queue up to listen to you. As well as his lectures to students at King's, Tutu is giving during his stay in Britain one major public address, the annual Longford Lecture, set up in memory of the late Labour politician and prison reformer, Lord Longford. He intends to draw on his experiences, in the immediate aftermath of South Africa's first democratic elections in 1994, of setting up and chairing the Truth and Reconciliation Commission. Its brief was to confront three decades of political violence in South Africa, but to do so by finding a third way between Nuremberg-style war-crime trials and national amnesia. There were to be no show trials, but no sweeping things under the carpet, either.
"At the time, South Africa," he recalls, "was very significantly a post-conflict society that could have gone so many different ways. Mostly people had predicted that it was going to be quite calamitous. And it hasn't been. Which is why there is so much interest [in South Africa] virtually everywhere you go in the world. At the Truth and Reconciliation Commission we were always careful not to promote ourselves as providing a blueprint for anyone. Situations are unique. But it is possible for people to learn from both the successes and the undoubted failures of our particular process."
Despite his caution about the South African model, it is frequently quoted as an option for war-torn societies - most recently in Iraq. There have, however, been many criticisms of the commission's work within South Africa. Some felt Tutu was too harsh on those who had been fighting for liberation, others that he trod too gently with the likes of his old friend, Winnie Mandela, who stood accused of very serious crimes. Her former husband, who spent his first night of freedom after release from Robben Island at Tutu's home, accepted the findings of the commission with, as Tutu puts it, "all its imperfections". It was in many ways an impossible task, but most now accept that it was at the very least a cathartic experience for the new South Africa.
Tutu himself freely acknowledges its imperfections. "For me, our greatest failing was not to be able to engage white South Africans more enthusiastically. They were badly let down by their leaders. They should have had leaders who said, 'You don't know how lucky you are. You should engage in this as enthusiastically as you can because the alternatives are quite ghastly and we are extremely fortunate that these blacks who have been victims over so many centuries should be ready to forgive.' Instead, those leaders were by and large too clever by half. They were splitting hairs and undermining the whole spirit of the process. Yet there was this incredible generosity - and not just from black people, though most of the victims would obviously be black. It was quite extraordinary."
He stretches this last word into a sentence in its own right and then leaves a pause before going on again at a gallop. "When we had listened to the testimony of people who had suffered grievously, and it all worked itself out to the point where they were ready to forgive and embrace the perpetrators, I would frequently say: 'I think we ought to keep quiet now. We are in the presence of something holy. We ought metaphorically to take off our shoes because we are standing on holy ground.'"
While Tutu vigorously denies any claim that such awe-inspiring forgiveness is in any way an exclusively religious virtue, he notes that "even the most secular person, trying to describe what happened in South Africa, found they had to use religious language. Everybody said that the only way you can describe this adequately is to say it is a miracle."
It is this miracle on which his reputation as a living saint mostly rests. But has it, as has been suggested of late, all gone sour? South Africa is moving towards election time, and many question the record of the ANC and their apparently unbreakable grip on power. Tutu has obviously had many requests for his analysis, and for once he is reluctant to answer, but seems to accept that he must. "Things could have been a great deal better at home," he says, picking his way through the words as if on tiptoe, "but I also say they could have been a great deal worse. I want to be enthusiastic and our country has the capacity to be a scintillating success. One of the things you do get to learn is how apt theology is." He's back in his stride now.
"It says that there is something called original sin. It afflicts all of us. We used to think fondly that because our case was just and noble, and because people were idealistic, that they would always remain so, but some people have started to be slightly less than idealistic."
He refuses to name names and prefers to dwell on the positive. "There are good people in government - people who have done quite well. We have to commend the fact that our country has achieved the level of stability it has. Russia made transition about the same time as us, yet if you contrast us to what is happening there, South Africa is really a Sunday school picnic." He tries a laugh to break the cloud that has descended on the room, but for once it sounds half-hearted.
However, it is clearly impossible for him to remain downcast - at least in public - for more than a minute or two, and soon he is back on form. Aside from being unwanted, as yet, in heaven, what has happened with his cancer? "I think they have zapped it good and proper. Cancer is a very sly and cunning so-and-so, but I had radiation treatment then cyrosurgery in the United States. They freeze the prostate - and you hope that's all they freeze." He thumps me on the arm as he collapses into laughter. Heaven's loss, I can't help thinking, is our gain.
Archbishop Desmond Tutu will be giving the Longford Lecture on Monday 16 February at 6.30pm at Church House, Westminster, London SW1 (020-7251 5070). Tickets are freeReuse content