A short while ago, at 6.45 pm UK time, Pope Benedict XVI's Alitalia plane, "Shepherd One", threaded its way into the lead skies above Birmingham Airport back to Rome, after a brief departure ceremony in which the prime minister, David Cameron, told him that he had "challenged the whole country to sit up and think".
On this "truly historic first State Visit to Britain," the prime minister said, "you have spoken to a nation of 6 million Catholics but you have been heard by a nation of more than 60 million citizens and by many millions more all around the world." Faith, he said, was "part of the fabric of our country ... a vital part of our national conversation. And we are proud of that."
A country of faith? Challenged to think by the Pope? Something seems to have happened here.
And it has. The spontaneous crowds, the wall-to-wall media coverage, the seeming fascination with the dialogue Pope Benedict sought to have with Britain, are all indications that this unusually state guest was received not with apathy or hostility -- as the media before last Thursday were warning he would be -- but with curiosity and receptivity. This has clearly been a shock for a largely liberal, metropolitan media.The Catholic commentator Clifford Longley, with whom I shared a radio studio this morning, drew a comparison with the US media discovering after George W Bush's election that they had ignored the influence of the flyover states.
There is something of a similar self-questioning evident now: why, when they could only pull together 6,000 demonstrators -- not an insignificant number, but paltry compared to the 200,000 who lined the streets yesterday, and the 80,000 in Hyde Park -- did the media give the anti-Pope protesters so much air time? Or, expressed another way: where the heck did all these people come from?
The answer is, of course, that many came precisely because of the airtime given over to the the gay rights activists, secularists and professional atheists. Catholics are loyal to popes, and to the papacy. They may not know how to answer the protesters' shrill objections, but they know when the leader of their Church is being unfairly trashed. A large number of the "vox pops" interviewed on Sky and the BBC mentioned this as the reason why they decided to line the streets of Whitehall six people deep.
"Everyone is agreed about the great success, not so much from the point of view of the numbers, but ... by the fact that the message of the pope was received with respect and joy by the faithful," the Pope's spokesman, Federico Lombardi, told reporters earlier today. The Vatican has already declared the visit a triumph, and no one seems to disagree.
After the Mass of Beatification of Cardinal Newman, the Pope paid a private visit to the Oratory before going onto to Oscott College, the seminary for the diocese of Birmingham, where he met with the bishops of England, Scotland and Wales.
In his address to them, referring to "the urgent need to proclaim the Gospel afresh in a highly secularized environment", he seemed to suggest an answer to the mystery now being pondered by the media: why, if Britain is so secular, was he received so enthusiastically? "In the course of my visit," he said, "it has become clear to me how deep a thirst there is among the British people for the Good News of Jesus Christ." Is that right? Is Britain -- post-Christian, secular, "believing but not belonging" Britain -- really so hungry for what the Pope has to offer? He certainly seemed, in these four days, to think so, praising great British virtues which he saw as rooted in the nation's Christian legacy.
He told the bishops: "As you proclaim the coming of the Kingdom, with its promise of hope for the poor and the needy, the sick and the elderly, the unborn and the neglected, be sure to present in its fulness the life-giving message of the Gospel, including those elements which call into question the widespread assumptions of today's culture."
He also returned, again, to the clerical sex abuse crisis, a theme which in the last two days of his visit has emerged as almost as important as the argument for the inclusion of faith in public life.
He praised the bishops for having taken "serious steps to remedy this situation, to ensure that children are effectively protected from harm and to deal properly and transparently with allegations as they arise", and called on them "to share the lessons you have learned with the wider community. Indeed, what better way could there be of making reparation for these sins than by reaching out, in a humble spirit of compassion, towards children who continue to suffer abuse elswhere?"
A short time ago I was watching the Archbishop of Westminster, Vincent Nichols, sum this up on the BBC. "What better way for the Church to do penance for its failures than by helping wider society deal better with the abuse in its midst?" he asked.
Pope Benedict also asked the bishops to be "generous" in their response to applications to the ordinariate, which "should be seen as a prophetic gesture that can contribute positively to the developing relations between Anglicans and Catholics" by promoting unity while accepting differences.
He also asked them to see the new English translation of the Mass, "as an opportunity ... for in-depth catechesis on the Eucharist and renewed devotion in the manner of its celebration."
In his closing remarks at Birmingham airport, Pope Benedict thanked the British people for the warmth of their welcome, and spoke again of the challenge of building a pluralistic society, as well as the opportunity for doing so through intercultural dialogue.
Although he had come with a fierce message about the vital importance of the place of faith in public life and education, it had been framed, throughout, in terms and language and symbols which pointed to the value of dialogue and respect. It is this, perhaps above all, which floored his critics. The Pope's was a message which all could instantly recognise as the true humanism.
He leaves a Church invigorated and unified by his visit; a Church more proud and confident than it was last Wednesday; a Church which will be pondering some magnificent texts for many years to come - -and images of a Pope whose smiling, gentle countenance speaks of the kind of humanism Britain will need to prosper.