The succession: The choices facing the cardinal electors are many and varied and will be weighed carefully, writes Paddy Agnew
So then, who will next sit on the seat of Peter? Popular wisdom would have us believe that the answer to that question is about as simple as naming the winner of next year's Grand National.
After all, when 111 cardinal electors went into conclave in October 1978, few commentators were confidently predicting that 58-year-old Polish Cardinal Karol Wojtyla would emerge as Pope. For some, the next few days will be an opportunity to repeat that famous old Vatican adage, namely that "he who enters a conclave as pope emerges as cardinal".
More cynical commentators may also point to another less charitable but equally celebrated adage, namely that "he who is elected pope is the cardinal with least enemies".
In vain, it seems, senior Curia figures and good Catholics all over the world try to remind the unrelenting media posse that the Pope's election does not depend on late-night real-politik sessions among cardinals gathered round a smoky restaurant table just off the Borgo Pio.
No, they tell us, the Pope's election is the expression of the divine will of the Holy Spirit, working through the cardinals.
Yet, while it is true that no one can predict the outcome of a papal conclave with certainty, given its highly peculiar, one-off, behind closed-doors nature, there are still a number of factors which may indicate a shortlist of probable candidates. Even if it is 27 years since the College of Cardinals last sat down to elect a Pope, there is still a pontifical "form book".
When the cardinal electors (all under 80, mobile phones turned off, please) go into conclave shortly, they will have to resolve an ongoing tension within the Catholic Church about the way forward. The very length and impact of John Paul II's pontificate, in themselves, prompt the first questions they may address.
After such a long and influential pontificate, during which Pope John Paul II became a major player on the world stage, has the time come for a radical change of style, if not direction? Do they want a relatively young, vigorous Pope who will continue in the evangelical tradition of John Paul II or do they want a less media friendly, older Pope who would represent a "safe pair of hands" and guarantee a quiet period of transition?
Then, too, the cardinals will have to ask themselves if they want a Pope who may seem to represent doctrinal change and innovation by comparison with the doctrinally conservative but politically innovative John Paul II. Conservative cardinals will argue that such has been the force of John Paul II's rigidly orthodox teaching that there can be no room for a doctrinal innovator.
Others might argue that such has been the impact of the sex-abuse scandals on the Catholic Church worldwide, and such is the growing North-South, rich-poor gap, that the next Pope will simply have to be an innovator, both doctrinally and in terms of the church's social teachings. In this latter context, some cardinals may feel that the time has come for the church to send out a strong signal by electing a non-European Pope, someone from the developing world.
The tensions which manifest themselves within this conclave will be about more than a battle between "left" and "right" factions, between "conservatives" and "liberals" within the church (even if these secular terms are hardly appropriate). For example, the choice of many of the non-curia cardinals (those who do not work in the Vatican) could well be influenced by a belief that the time has come to rein in the Curia, reducing its all-dominant role in church affairs while giving greater voice and autonomy to the local churches.
Given the epoch-making nature of John Paul II's pontificate, it is stating only the obvious to point out that he will inevitably prove a very hard act to follow. Should the next Pope be as fluent a linguist, as gifted a communicator and as able a politician as John Paul II (providing that such a person exists)?
Would it not be better for the church to opt for an older cardinal, a transitional Pope who would project a more pastoral, apolitical and less aggressive image of his evangelical mission? Or, has the time come for the next Pope to consider change to controversial, non-doctrinal tenets of church teaching such as priestly celibacy and the ban on women priests, teachings based on church law rather than divine law?
There is certainly a current of thought within the Holy See which suggests that, just now, the Catholic Church needs to take a time-out, to choose a safe-hands candidate (perhaps an Italian, probably in his 70s) in order to pause for thought. If there is to be a great reforming Pope in the future, he may be the Pope after next and not the one about to be chosen.
To sum up then, the cardinals may ask themselves at least three basic questions before arriving at their choice. What age should the new Pope be? Should he come from the developing world or from the first world? Should he come from the Curia or from a diocese?
We can perhaps dismiss at least one of the many clichés sure to be churned out over the next few days. Namely that, because John Paul II has appointed more than 95 per cent of the cardinal electors, his successor will simply have to be someone who follows on with a similar brand of doctrinally rigid and orthodox Catholic teaching.
Indeed, history shows that the longer a Pope remains in office, the less likely it is that he will be followed by a photocopy of himself. There is a sort of pendulum effect at work here. For example, John XXIII was totally different from Pius XII, and Paul VI very different from John XXIII and John Paul I very different from Paul VI and so on.
The shakers and makers in this debate are, of course, the grandi elettori - cardinals who might once have been papal candidates themselves but who have been outflanked by John Paul II's longevity.
Focal point for the liberal corner may well be the Jesuit cardinal and former archbishop of Milan, Carlo Maria Martini, while the conservative camp is likely to have as standard-bearer the imposing figure of German Cardinal Joseph Ratzinger, prefect of the Congregation for the Doctrine of the Faith (ex-Holy Office), who in recent times has been spoken of as a possible successor himself and not just kingmaker.
These two wings have even squabbled publicly. There was the famous occasion at the October 1999 Second Synod for Europe when one of the leading right-wing candidates, the recently nominated Archbishop of Milan, Cardinal Dionigi Tettamanzi, delivered a distinct put-down at the synod of ideas from Cardinal Martini.
Cardinal Martini had called for more collegiality in church affairs, proposing some kind of third Vatican Council or effective body of bishops and laity, men and women, who would come together to plan the church's way forward in the next millennium. Significantly, Cardinal Tettamanzi told reporters that Cardinal Martini's call for a new body "had found no echo" within the synod.
Other significant church events in recent years, including Cardinal Martini's call for a rethink of Petrine primacy, Cardinal Ratzinger's uncompromising Dominus Jesus declaration of September 2000 and even the controversial beatifications of Pope Pius IX or the founder of Opus Dei, José-Maria Escriva, could all be seen as part of the jockeying for position over the way forward.
As for the candidates themselves (see panel below), there are several obvious names. As already stated, Cardinal Tettamanzi looks like an "official" orthodox church candidate, backed not only by the Italian hierarchy and the Curia but also looked on favourably by influential lay organisations such as Opus Dei and Communione e Liberazione.
Others who come within the orthodox umbrella are the Cardinal of Bologna, Giacomo Biffi, and the Cardinal of Vienna, Christophe Schoenborn.
When it comes to"safe hands" or compromise choices, then Vatican insiders such as Italian Cardinal Angelo Sodano, the Secretary of State, Giovanni Battista Re, prefect of the Congregation of Bishops, could emerge.
In recent years, media speculation has often suggested that the time has come for a non-European Pope from the developing world. In this context, much has been made of the candidacy of Nigerian Francis Arinze, president of the Pontifical Council for Inter-religious Dialogue and the media's "first black Pope".
In reality, however, if there is to be a non-European, it is more likely that he will come from Latin America, which features two of the leading "liberal" candidates in Honduran Oscar Andres Rodriguez Maradiaga, Archbishop of Tegucigalpa, and Brazilian Franciscan Claudio Hummes, Archbishop of Sao Paulo.
Latin America also fields a possible conservative candidate in Cardinal Nicolas de Jesus Lopez Rodriguez, Archbishop of Santo Domingo.
Other "liberal" candidates could include German Cardinal Walter Kaspar, president of the Council for Christian Unity, and Belgian Godfried Danneels, Archbishop of Brussels.
Having said all that, however, it is quite possible that the name of the new Pope does not figure above. After all, John Paul II was himself a compromise candidate, elected after the cardinals split on a choice between Cardinals Siri and Benelli.
Above all, the Holy Spirit works in mysterious ways.