YOU know that very annoying response you sometimes get to a statement of the bleeding obvious? Not the one about bears in the wood, but the one where someone says: “Is the Pope a Catholic?”

I reckon it must be at least 40 years since this seemed an original way of saying “duh, of course”, but the visit of Pope Francis to Ireland brought it to mind. It wasn’t a concern about His Holiness’s doctrinal purity – though some conservative Catholics have raised questions about the current Bishop of Rome since his encyclical Amoris laetitia seemed to imply a change to the traditional teaching on communion for divorced and remarried congregants. But I think I’ll leave the debate on whether the Pope is “catholic” as opposed to “heterodox” or “schismatic” to them.

I was thinking of “catholic” in its meaning of “universal”, and the Pope’s visit provided a pretty obvious illustration of the fact that that description can no longer be relied upon. If there’s anywhere that the Catholic Church should be able to count on a good turnout, it ought to be in Ireland.

During the papal visit of St John Paul II there – as it happens, about 40 years ago – more than half the population of the country turned out to see him at one point or another, and almost a million and a half, one-third of the population, attended the Mass he celebrated in Phoenix Park. By contrast, the most optimistic estimate for Pope Francis’s service was 300,000. That came from the Vatican and, while it may seem uncharitable to doubt its truthfulness, other observers thought the numbers were more like half that.

Trying to brush away that sort of decline with excuses about the weather, or by pointing out that Francis is a less impressive pontiff than his predecessors, cannot account for the profound change in support for the church in Ireland.

It is not merely in Ireland that Catholicism is in decline, of course. Though there are now more nominal Catholics than ever before (around one and a quarter billion), decline in church attendance over the period since John Paul II’s Irish visit has been sharp: from 37 per cent to fewer than 20 per cent in Europe, and from 53 per cent to under 30 per cent in the Americas.

Naturally, attendance is just one measure, and other Christian denominations (with a few notable exceptions) have seen similar declines. But the Catholic Church faces two different problems, both very clearly apparent in Ireland, which affect it more than other religious groups.

The first is the huge change in social attitudes over the past decades. In Ireland, that tendency has been amplified by the relative youth of the population: the 1970s saw the population grow by more than 13 per cent, and there are a million and a half more people now than there were in 1979. Attitudes on issues such as abortion, contraception, divorce and homosexuality have not merely liberalised, they can almost be described as the polar opposite of what was the norm half a century ago and, in many cases, enshrined in legislation.

It’s probably difficult for anyone under the age of 50 to realise quite how profoundly widespread the change in social attitudes has been; it would certainly have been unimaginable in 1979 that a future papal visit would feature an openly gay Taoiseach lecturing the Vicar of Christ on the inadequacies of traditional Catholic teaching on the family.

Other Christian denominations, such as the Church of Scotland, have altered their teaching on many of these issues or (in the case of the Church of England) taken elaborate steps to avoid being nailed down on them. And the evidence suggests that many American Catholics, for example, simply ignore many of their church’s core tenets.

But it’s difficult, and many would say impossible, for the Roman Catholic Church to alter its magisterium. It could, if it wanted, alter its stance on, for example, clerical celibacy, since that is a matter of church discipline rather than doctrine (there are former Anglican clerics who are married and now serving as Catholic priests in the Ordinariate).

But the tradition of the church holds that on other liberal measures – ordaining women, permitting contraception, recognising same-sex marriages – which seem obvious to most secular people, and a good many clergy in other traditions, it cannot change, even if it wanted to. That may annoy modern sensibilities and seem a good reason for many people to reject Catholic teaching, but it’s difficult to see that anything can be done about it. If your priorities are the eternal, moving with the times is not really an option.

The other problem, and the one which overshadowed much of Pope Francis’s visit, is an altogether different matter. The numerous scandals surrounding clerical abuse, and the church’s refusal to tackle the matter, but instead to conceal it, led the Pope to beg forgiveness from his audiences in Ireland. Indeed, most of the applause he received seems to have been confined to these apologies.

Apologies, however, are not nearly enough. It’s now apparent that wicked and straightforwardly criminal behaviour has, over the course of decades, been at best ignored and in some cases actively enabled by church authorities. Even as the Pope expressed his remorse in Ireland and correctly characterised the historical abuses as “filth”, there were calls – from an Archbishop – for him to resign for having ignored warnings about alleged abuse by a prominent US cardinal, and indeed reversed the sanctions placed upon him by his predecessor, Pope Benedict.

So far, no concrete evidence has been produced to back up this claim, and the Pope has declined to comment. But the stench of the scandals already proven, and the testimony of victims, many of whom were protesting prominently in Ireland, are quite enough to require a systematic, open and wholesale review of such cases.

The church may not be able to do much about general disaffection with its moral teaching, but it must recognise that failing to tackle crimes committed by those within its own ranks call into question its commitment to its own doctrines. The church cannot expect anyone to take it seriously if it fails to tackle immorality, hypocrisy and abuse. And these are not temporal issues of shifting moral attitudes; they are crimes which have always ranked amongst the most wicked, and should always have been met with outright condemnation and appropriate punishment.