One of the things that may strike people about the theme of this year's Catholic secondary heads' conference - "Values and citizenship: the Catholic school as a community of shared values" - is the term "values" rather than "beliefs".
Speaking of the distinction between "beliefs" and "values", Pat Sweeney, the head of St Margaret's Academy in Livingston, says: "If you compare the school I went to as a boy with the one I now preside over, they are very different establishments.
"I went to St Francis' Primary in the Gorbals in a parish run by the Franciscans, where you could be fairly sure that the teachers, parents and everyone involved held the same beliefs in every detail. You cannot make that assumption in Livingston in 2004.
"We still adhere to the Catholic faith and the teaching of the Church, to varying degrees. However, the consensus is more about a code of shared values than about an identical set of beliefs.
"To try to create a citadel in which 100 per cent of the population have shared beliefs is artificial and doomed to failure.
"The reality is that the Catholic school embraces a diversity of cultures, backgrounds, needs, abilities and social status, perhaps even to a greater degree than non-denominational schools because of the size of our catchment area."
Mike Knox, depute headteacher at Holy Rood High in Edinburgh, agrees. "The dynamism of the Catholic school is open to all. It's not about building an ark and hiding secrets. Catholic schools are places of hospitality and fellowship, places for gathering people together."
At both schools, about a quarter of the pupils are non-Catholic; in Livingston, most of these are religiously non-declared or nominally Protestant, while Holy Rood also attracts Muslims and Sikhs. Neither school has experience of pupils withdrawing from attending religious and moral education classes or sharing in the liturgy.
Kerry McLaren, Holy Rood High's lay chaplain and principal teacher of RME, argues that RME is about enabling pupils to deepen their own spirituality rather than about instruction. Topics such as contraception, abortion, euthanasia and pre-marital sex are debated openly, but within the context of Christian and Catholic values.
"My job is to impart these values and explain why the Church teaches what it does," she says, "but ultimately the pupils will make up their own minds. They will make their own decisions."
"The nature of RME has developed significantly over the past 20 years," says Mr Knox. "You're enabling young people to reflect on their own lives and experience in the context of the values and beliefs of the Christian community. Non-Catholics can explore the same issues and see how they are expressed in their own religious tradition. World religions are integral to RME.
"You're helping all pupils to reflect, discover and deepen their faith.
Indoctrination is contrary to the process of religious formation and education."
Ms McLaren says: "Liturgy is the celebration, and putting to God, of the lived experience of our community. Prayer comes from the pupils. They have input into the who, why, what, how and where we pray. They are involved in choosing music, decoration, symbols, content and context.
"Non-Catholics are fully part of this. No one has ever withdrawn, in my experience, including Muslims, Sikhs and atheists."
Both Mr Sweeney and Mr Knox believe the shared values of Catholic schools make them socially inclusive by definition and naturally predisposed towards promoting citizenship.
"Pupils are encouraged to take a strong active role as members of the school community and beyond," says Mr Knox. During Lent, they raised pound;7,000 for causes the pupil council selected, including support for young carers, young homeless people and young people with HIV.
In terms of global citizenship, Holy Rood has strong links with Lombeta Secondary in Tanzania. Last year pupils raised money to buy computers for the school, two groups of pupils visited it, two teachers went on four-week placements and for a year a Tanzanian has been training at Holy Rood to support Lombeta staff in information technology developments.
The pupil council is also setting up a company, Lombeta Inc, to market ICT products, with the profits going towards supporting the schools' links.
"The Catholic school's core values are what I would call kingdom centred values," says Mr Knox. "They are forgiveness, service, outreach and inclusion. For me, the key value arising from this is not independence but interdependence."
Mr Sweeney lists the shared values at St Margaret's as respect and care for human life, promotion of justice and peace, and service to others, all of which are founded on Gospel values.
Far from seeing faith schools as anachronistic or outdated, he believes they have even greater importance to society than previously. "The Catholic school has probably a more important role to play in a pluralistic society now in exemplifying the values of the Gospel in action and in showing their relevance to 21st century Scotland," he says.
"The adherence to a set of explicit values is an important feature of any school. Sometimes it's more overt and visible in the life of the Catholic school and it may be more difficult to create a consensus around a set of values in a pluralistic setting than in the Catholic school, where there is some homogeneity. To be explicit about your standards and to try to maintain them vigorously is perhaps a feature of the successful Catholic school."
Speaking of success, research by Edinburgh University found that of those working class pupils with two or more Highers, 52 per cent were from Catholic schools, compared to 42 per cent from non-denominational schools.
Professor Lindsay Paterson of Edinburgh University says: "Catholic schools have been a classic instance of education's capacity to integrate socially-excluded groups into the mainstream.".
Mr Sweeney says: "I like to think that this high achievement emanates from the values we espouse and the standards we expect.
"We have a lot of non-Catholic parents trying to get their children into St Margaret's. Though most speak of our high levels of attainment and few mention religion explicitly, I don't think we can divorce attainment from the shared values we promote."
Mr Knox agrees. "Non-Catholic parents are attracted by the reputation of Holy Rood High as a good education establishment where their children can succeed. I believe they are attracted by the ethos, the quality of pastoral care and the sense of community, and you can't divorce these from what are essentially Christian values."
He acknowledges that integration into Catholic life is equally important to the Catholic school. "Membership of the Catholic community has always been an integral part of the Catholic vision of education, the model of which is the parents, parish and community working together, and this has always been a strong feature of Holy Rood," he says.
"The Catholic school is a community of faith that would encourage religious practice within the Catholic community, remembering that the primary religious educators are the parents."
He adds: "Many pupils experience the school as their real community, rather than their geographical neighbourhood, at this stage in their lives. It's the place where many make sense of their lives. Our aim is to support them and make them good global citizens."
Ten senior pupils at St Margaret's Academy spoke about their religious outlook and the ethos and shared values of the school. Eight of them are Catholic, one describes himself as Catholic "but not a member of the club" (he was not baptised) and one is non-Catholic.
Only one of the confirmed Catholics describes himself as a regular church goer, but all 10 say they have faith and eight, including the non-Catholic and non-confirmed Catholic, say they pray regularly in private.
"You could go to church regularly and still be a mean person," says one.
"You don't have to go to church to be a good Catholic."
"It's about believing in God," says another. "If you believe in God you should go to church when you feel the need."
"Faith is expressed in our charity work. Love your neighbour."
"It's about good morals; it's about the way you treat other people."
On the ethos of the school and shared values, they all agree when one pupil says: "We all respect each other better here because it's a Catholic school."
"You feel that it's to do with the Catholic ethos of the school that we do a lot of charity work for Third World causes, that we give blood, do sponsored fasts and take collections."
"There's a good relationship between pupils and teachers here. You feel the teachers respect you and you respect them," says another.
They feel their friendships and peer relationships are school based rather than neighbourhood based. "You definitely belong to a community, especially as seniors," one says. "There's a togetherness."
On the sense of community, one pupil says: "We all feel our school is better than those of our friends elsewhere. It's more welcoming and there's very little bullying. In other schools, there seems to be quite a lot of hostility among the pupils."
They see wearing school uniform as positive, as promoting a communal identity. One girl even says it makes her work harder.
All the pupils plan to go on to university, nine of them saying they will be the first of their families to do so.
Each was asked to sum up the ethos and values of the school in one word.
They answer: togetherness (twice), community, family, welcome, equality, compassion, respect, trust and positivity.