When Francis returns to the Vatican, will he leave behind a different Ireland? Will he be returning to a changing institutional church? Does his visit amount to some form of watershed in the relationship between the Irish people and their state and and the Roman Catholic church?
Or will his short visit amount to a brief episode in a longterm, irreversible historical process of transformation both within the Catholic church and between that church and the Irish people?
The first question is whether this papal visit will have any greater outcome for Ireland than the visit of Pope John Paul in 1979? To answer that question, one must first consider whether the 1979 papal visit actually had any significant lasting effect on Ireland and the Irish.
In truth, it is very difficult to argue that the 1979 visit changed Ireland or that Irish history would have been significantly different if John Paul had decided not to come to Ireland.
Did the youth meeting at Ballybrit halt the decline in religious practice among the young - a decline that had started well before the visit? Was there a surge in vocations? Did religious practice rebound? Did the Irish Catholic church itself change? The answer to these questions must, in truth, be in the negative.
So it is very difficult to see how this Pope, a very different man from John Paul, is going to change Ireland, the Irish or the Irish Catholic church by this visit, or even to see how the World Meeting of Families in Dublin can have any lasting transformative effect.
With Irish Catholic bishops openly predicting a contracting role for the institutional church - a "smaller church"- in Irish society, there is little or no optimism for any form of recovery in the political or social status of the church.
But that is only half the question. There is another more important issue.
Accepting that the Church will be smaller, what kind of smaller church will it be?
Is there within the male, clerical, institutional church any real appetite or capacity for reform? Is church teaching or doctrine going to change? Or is the male hierarchical church as we know it condemned to fossilisation as an institution and as a set of beliefs?
A shrinking church may, on one view, refuse reform and see itself as needing to get "back to basics", reverting to the doctrines, beliefs and practices of a century ago, content to weather the storm.
On another view, the Catholic church, confronted with what appears to be an inexorable decline in the developed world may choose to migrate spiritually to the developing world - a less sceptical audience - as its future theatre of operations.
While the various scandals have rocked the institutional church in the eyes of the developed world, we should recall that the process of decline started before these scandals came to the fore. In Quebec, for instance, the decline in Catholic religious practice started in the 1960s and progressed just as far as it has later done in Ireland in the last few decades.
The scandals are perhaps catalysts which boost the speed of decline; the decline cannot be wholly or even mainly explained by them.
Strangely, it may be the case that it was the decline in practice and belief that brought the scandals out into the open rather than the reverse. After all, the community served by the Magdalen laundries knew all about them but averted its gaze because it readily accepted the "morality" that placed women there.
While the Catholic faithful subjected themselves unquestioningly to the authority of the clerical church, the scandals could remain hidden.
As the Church saw it, the greater sin by far - the sin of scandal giving - lay in bringing the depravity, the corruption, and the wrongdoing to the attention of the innocent faithful in a way that might damage or imperil their innocence, and their faith in, and their obedience to, the Church itself.
Secrecy and "suppressio veri" were viewed as virtuous if deployed in the interests of the Church itself and for the avoidance of scandal.
So while the growing mass of evidence of the church covering up its scandals now dominates the horizon, not least in the recent Pennsylvania Grand Jury report, the Catholic church's problems run deeper than the scandals and the cover-ups; the church's difficulties stem from the intrinsic nature of the institutional, clerical church itself.
What chance has Francis of reforming the institutional Church?
To answer that, we need to look at a few issues that stand in the way of reform.
Perhaps the biggest stumbling block or what may turn out to be the millstone around the neck of the institutional church is its self-idolatry as expressed in its claims to being the exclusive means of salvation and its claims to be infallible. This proud self-image prevents it from humbly admitting and addressing institutional error and sin.
Rome thinks it cannot do a u-turn on contraception because of the papal encyclicals Casti Connubii and Humane Vitae. Any thinking person can see that there is no logical connection between Christian belief and prohibiting contraception. But two popes solemnly pronounced that "artificial" contraception infringes God's law and the natural law and is intrinsically evil and sinful.
Only a male, celibate and entirely fallible institution could have made that mistake.
Can a male, celibate and self-professedly infallible institution now humbly admit that it got contraception wrong?
Can such a male, celibate and self-professedly infallible institution humbly admit that a believing Christian may be fully part of that institution although divorced and happily remarried?
Interestingly, I recently discovered that the members of the powerful, political lay body, the Catholic Committee, in Dublin in the 1790s not merely repudiated the idea of papal infallibility but secured the concurrence of the then Catholic archbishop of Dublin in a formal rejection of the theory.
The promulgation of papal infallibility in 1870 was controversial even then. It seems indefensible now just as it did to Dublin's Catholic Committee in the 1790s. It is a doctrinal claim that hangs from its own boot laces and one which is seriously damaging to the Catholic church in its behaviour and attitudes.
Reformists such as the We Are Church movement and Mary McAleese make an almost unanswerable case for ending the discriminations against women in the institutional church. Surveys suggest that most Catholics agree with them.
But that also raises the question: "Exactly what would persuade the institutional church in Rome to treat men and women equally?"
It seems to me that the present existential threat to the Catholic church's survival is not yet seen in Rome as a reason to consider such a reform. Many members of the male hierarchy would, it seems, prefer to do down with the ship than allow priests to marry or women to become priests.
The Catholic doctrinal obsession with sexuality, sexual morality, and their exaltation of celibacy, purity and virginity are all part of a piece with the circumstances that have given us the abuse scandals, the cover-ups and the self-destructive behaviour of the hierarchical church.
I find it hard to believe that a non-celibate hierarchical clergy could condemn contraception as intrinsically evil and sinful.
Even Paul the Evangelist, who seems to have preferred a subordinate role for women in the early churches, wrote in his First Letter to Timothy urging that the bishops in those churches should be married!
But the Roman hierarchy prefers to ignore both scripture and the views of the laity and many brave clergy by insisting not merely on clerical celibacy - well at least in the Western church - but in prohibiting the clergy from discussing the issue at all!
It is all very well for a liberal priest, Fr James Martin SJ, to point out at the World Meeting that the Catholic church is treating gay people like lepers. But does the Catholic church in Ireland require of teachers that they instruct pupils in Catholic secondary schools that their gay class-mates are disordered and that acting on their orientation at any point in their lives will be intrinsically evil and merit eternal damnation? Or do they realise that such a doctrine is absurd and unchristian in the eyes of those pupils.
And will anyone in Rome listen to and respect and respond to those who applauded Fr Martin's speech?
Irish views of what is right and wrong, tolerable and intolerable, and christian and unchristian, are in many respects diverging from the views of the Roman Catholic institutional church. The state and the people no longer see the institutional church as holy and authoritative in the way their parents and grand-parents saw it.
Francis is one human being. He is surrounded by a hierarchical institution of men who are not attracted to reform, who believe that they collectively are guided by God in their decisions and practices, who believe that they are entitled to the obedience of the faithful, and believe that they are axiomatically incapable of collective error.
Francis seems a kindly and intelligent man. He wasn't invited here for a dressing down. He wasn't invited to be confronted with disbelief or disputation. He knows some of the problems. His critics don't know many of his problems.
There are profound questions for Ireland too.
Is the contracting, smaller future church going to abandon its role in education, welfare, and health? Are these areas to be the theatre of operations for the all-powerful State alone? Is social voluntarism and philanthropic initiative to wither and die with mass religious practice? Is social morality to be the mere ghost of religious morality?
These few days bring these issues into focus. But resolving them will take more than a few days.