There was a time in Ireland when talking on television about priests getting drunk, swearing and lusting after women - even if it was only a joke - meant trouble.

However, Father Ted (made for Channel 4 but eventually screened on RTE), a sitcom which portrayed priestly life as a litany of insane events laced with "drink, feck, girls", and even, God forbid, homosexual innuendo, was one of the most successful television comedies ever see here.

How does a television programme like this get around laws designed to censor media deemed blasphemous or immoral? How can a book by James Joyce which contains some erotic and intimate passages be banned under the same act which today allows for the wide availability of soft pornography? And how can similar legislation ban a film like Last Tango in Paris, then give us Eyes Wide Shut?

Three separate pieces of legislation refer to material subject to censorship on radio and television, in publications and on film, but all three are open to interpretation. How you define moral decency depends on the values of a society. In Ireland the powerful influence of the Catholic Church for a long time gave it an exclusive on that definition.

Today, the same law as ever applies, but now that our values are determined by influences from all around the world, through travel and the media, Catholic teaching is only one factor influencing how we define morality.

Sex is no longer such a big deal. The sort of censorship which happens now is more likely to concern something considered racist or in some way offensive to a minority group.

This shift away from the old creeds is partly reflected in a controversial banning which happened earlier this year - the banning, believe it or not, of a radio advertisement for the Irish Catholic newspaper. The advertisement was banned by the Independent Radio and Television Commission (IRTC) under the Radio and Television Act 1988, which rules out ads directed towards a religious end.

The advertisement featured voice-overs of people praising the newspaper, one of whom said: "The Irish Catholic, a . . . newspaper that connects the issues of today with the teachings of the church". The chief executive of the IRTC, Michael O'Keeffe, said the decision had been taken to ban the ad because it made reference to promoting the teachings of a church.

The paper's editor, David Quinn, accused the IRTC of taking a "ludicrously strict interpretation of the Act", which he said was designed to prevent sectarian conflict on the airwaves. The ban went ahead. It is hard to see how the advertisement might be aligned with sectarian conflict. Does this instance of censorship reflects the values of a more pluralist society? Sex does not pass entirely unrestricted. Hardcore pornography remains strictly out of bounds here. Depending on the context and the age group which may be watching or reading, there are constraints. Even MTV, den of iniquity and depravity, has its limits. Videos by everyone from the Cardigans to the Prodigy have been banned or given a very late-night viewing slot, bearing in mind the average age of viewers.

However, these days violence and its portrayal is much more likely to rub against the cutting edge of censorship. Films with a lot of violence are either given an over-18s cert or banned - as in the case of Natural Born Killers and The Bad Lieutenant.

Other factors which influence censorship are developments in technology; in this respect the focus of censorship is directed at protecting children. These days parents have less control over what their children have access to; politicians have called for new laws to protect children from video games which contain violent and sexually explicit material.

Some cartoons and comics - which parents could be forgiven for assuming are kid-friendly - are full of both sex and violence. TV cartoons for older people are screened after the 9 p.m. watershed and shop owners are supposed to bag and topshelf certain comics. In an era when women's rights are strongly advocated, feminism has also been seen as an instrument of censorship. This argument is made most strongly with regard to pornography, which some feminists believe should be banned as demeaning and degrading. In 1995, Playboy magazine was un-banned in Ireland. While some members of the media argued for freedom of information and an adult's right to sexual titillation, claiming that being revered as a sex object was something we would all enjoy, others said pornographic magazines undermined a cause which was fighting for equality and the freedom of women worldwide.

On the one hand, the availability of Playboy was seen as the mark of a society which had reached a certain sexual maturity, one which was no longer so sexually repressed. On the other hand, this new found "liberation" was seen as humiliating and, in fact, oppressive of women. Where once it was argued that any reference to sex at all was likely to lead to immoral acts, the un-banning of Playboy was both celebrated by a society which advocated freedom of information and abhorred by a society which believes in a woman's dignity. By 1995, despite the fact that the legislation hadn't changed in over 50 years, values had changed (reflected by the various views which were expressed) and the Catholic Church had relatively little say at all.