"The man who risked everything...
To speak for those who could not...
To make the blind see...
And to lead a movement that would change the world."
Anyone who has seen the film Amazing Grace will appreciate the parallels between the career of William Wilberforce, as romanticised by Hollywood, and that of Tony Blair, as romanticised by Tony Blair.
Like Mr Blair, Wilberforce had his roots in the north of England. Like Mr Blair, he did not distinguish himself at Oxbridge. Like Mr Blair, he lost no time in entering politics, where his affability ensured rapid advancement. And, like Mr Blair, Wilberforce was strongly influenced by the Evangelical movement.
The revelation of "the infinite love, that Christ should die to save such a sinner" came to Wilberforce like a thunderbolt after he had entered Parliament.
But he was persuaded by (among others) the repentant slave trader and composer of Amazing Grace John Newton, that he could "do both": politics and God's work. It took a few false starts before, alerted to the atrocious conditions aboard slave ships making the transatlantic "Middle Passage", he found his cause c'lSbre.
The moral transformation of England achieved by the Evangelical movement, without which the law abolishing the slave trade would never have been passed, has its echoes in our own time.
Today, of course, most English people are faintly embarrassed by religion and regard Americans as rather absurd for reading the Bible. Nevertheless, the English retain an authentically 19th-century enthusiasm for moral crusades. Part of Mr Blair's original appeal as a politician was precisely the impression he gave of being able to lead one.
In our time, as in the 1800s, Africa has an especially strong appeal to the Evangelical sensibility. There is something irresistible about being able to feel simultaneously guilty about the continent's problems ("I once was blind...") and capable of solving them ("... but now I see").
The problem is, of course, that generation after generation thinks it has found the solution, and generation after generation is disappointed. Wilberforce and his friends were convinced that abolishing the slave trade, and then slavery itself, would do the trick.
To give them their due, they knew that actions always speak louder than mere legislation. It should never be forgotten that, after the passage of the abolition legislation in 1807, the Royal Navy waged a sustained campaign against those who defied the British ban. Indeed, the campaign against slavery was a classic example of unilateral humanitarian intervention, in which the rights of other nations were repeatedly violated.
Yet doing away with the slave trade had less impressive consequences than the reformers had hoped. The same was true of abolishing slavery itself. Most of Africa remained not much better off in 1907 than it had been in 1807.
So something else had to be tried, and that something was state-led economic development. Throughout the Fifties, well-meaning administrators in the Colonial Office toiled to enrich Africa with groundnut schemes and the like. With minimal success.
So we tried again. This time the solution was political independence. British self-doubt was a much more important cause than indigenous nationalism of the "winds of change" that began to blow through Africa in the Fifties and Sixties. With astonishing speed, all British colonies in Africa were granted their freedom. Again, disappointment. Economically, the majority of the countries in question did even worse under self-government than they had under British rule.
We tried lending them money. That didn't work. Then we gave them aid. That, too, had relatively meagre results. Many well-meaning people - led by that most Evangelical of economists, Jeffrey Sachs - continue to have faith in aid as a policy, arguing that it simply needs to be better targeted, for example on the provision of free malaria nets. But economists who know Africa better than Sachs are sceptical.
Oxford's Paul Collier, author of The Bottom Billion, persuasively argues that Africa's biggest problems (apart from incurable ones such as its location) are political. Corrupt tyrannies and civil wars between them account for a huge proportion of Africa's economic under-performance since the end of colonial rule.
For evidence of the persistence of the problem, just take a look at the excellent new Global Peace Index, produced at the instigation of the businessman and philanthropist Steve Killelea and published last week. The index ranks 121 nations according to a wide variety of indicators ranging from a nation's level of military expenditure to its human rights record. Eight out of the bottom 20 countries are - you guessed it - African. Plainly, lavishing debt forgiveness and aid on rogue regimes like Zimbabwe's or Sudan's, or failed states like Somalia or the Ivory Coast, is as big a waste of money as simply burning banknotes. The key question, persistently ducked by Sachs, is whether anything can be done by outsiders to break Africa's cycles of violence and misrule.
One of Collier's most interesting findings is that, until recently, former French colonies in Africa were less likely than their comparably poor neighbours to experience civil war. That was because the French (unlike the British) gave informal security guarantees to post-independence governments.
On the sole occasion when the British intervened to end violence in one of their former colonies, Sierra Leone in 2000, the results were dramatic. Freetown in the late Nineties had witnessed scenes out of Conrad's Heart of Darkness.
But when I went there not long after the British intervention, it was safe to walk the streets. "Thank God for Britain!" an elderly man exclaimed when he heard where I was from. I never expected to hear that in Africa.
Credit where credit is due. It was Mr Blair who sent the troops to Sierra Leone and ended the anarchy there. So I don't begrudge him his visit to Freetown last week. It was surely the most richly deserved ego-trip of his entire Sinatra-like farewell world tour.
Moreover, Mr Blair proceeded to give a speech in South Africa on Thursday which, as messianic speeches on the subject of Africa go, was one of the best I have ever heard from a Western leader. "Africa," he declared, "has been a prime example of a foreign policy that has been thoroughly interventionist. I believe in the power of political action to make the world better and the moral obligation to use it."
Great stuff. And pure Wilberforce. Mr Blair drew a compelling contrast between disastrous non-intervention (Rwanda) and successful intervention (Sierra Leone). He also used stronger language than we are used to hearing about the need for action in Darfur. Too bad he could not have chided the South African government more explicitly for its woeful tolerance of Robert Mugabe's tyranny in Zimbabwe
On economics, too, Mr Blair was on fine, early Victorian form. Like the Evangelicals before him, he believes more in trade than in aid. Yet he very nearly spoiled it all by succumbing to the most widespread confusion that currently exists in the minds of Western liberals. That confusion is that we can simultaneously eliminate global poverty and combat global climate change.
In a week when even President Bush seemed to concede the link between greenhouse gas emissions and global warming, it would have been good if Mr Blair could have admitted the truth. As Asia is proving beyond a shadow of a doubt, eliminating poverty means massively increasing carbon dioxide emissions. Africa, by contrast, is currently making a major environmental contribution by consistently failing to achievable sustainable growth.
If you don't believe me, just take a look at the data on per capita CO2 emissions. Sure enough, this is another of the many league tables where Africa comes bottom. Of the bottom 20 polluters in the world, no fewer than 15 are African. Go Africa! To save the planet all we need is a hundred years of African-style stagnation in the rest of the world.
As the careers of both Wilberforce and Tony Blair illustrate, Africa has always been good at generating hot air, particularly from the mouths of evangelically inclined Englishmen. Happily, it is only the moral climate that such emissions tend to change.