Catholic comprehensives and their success in transforming the life chances of working-class families are the "most fundamental force" in ending discrimination against the Roman Catholic community, one of the country's most eminent historians says.
Tom Devine, professor of history at Edinburgh University and once a young teacher at St Ambrose High, Coatbridge - in French and English - told Catholic headteachers at their conference in Crieff that there was now no evidence of Catholics being held back because of their religion.
Professor Devine described a "social revolution of quite unprecedented proportions", especially over the past 25 years as Scotland transformed its economy and values. For 35-year-olds, there was no ascertainable difference between Catholics and non-Catholics in terms of access to jobs. "The road out of the ghetto" had been through education.
A vast new professional and middle-class Catholic community was now established in line with its overall representation in the Scottish population. One in six Scots is born a Catholic.
In contrast, the Catholic community in the early part of the 20th century, Professor Devine said, was overwhelmingly working class, maintained an enormous solidarity with the Church and harboured "a fortress mentality and a basic ethnic defensiveness", nurtured since the Irish first came to Scotland in the 1790s.
Professor Devine said Scotland's "sectarian crisis" had been in the 1920s and 1930s, and in 1923 the church and nation committee of the Church of Scotland was openly talking about "the menace of the Irish race". Hostility was "racist as well as religious" and it continued in various forms through to the 1950s and beyond.
As late as 1952, the Church of Scotland had talked about "the alien race", but it had apologised.
The real poverty in the Catholic communities began to ease in the 1960s and 1970s, Professor Devine said, and since the early 1990s Britain, according to the OECD, had enjoyed the most constant and least volatile rise of personal incomes in the western world.
"The Catholic population to a greater or lesser extent has shared in it,"
Prior to that, the impact of the welfare state and state intervention in the economy from the late 1940s had helped the poorest in society to gain disproportionately. Jobs in the public sector were not subject to "the what school did you go to process or what particular echelon were you in the Boys' Brigade?"
Professor Devine said the "meltdown" of mining, engineering, shipbuilding and manufacturing under Thatcherism meant that "the citadels of discrimination", controlled by foremen, finally disappeared as new jobs emerged.
"Out of the maelstrom of the 1960s, 1970s and 1980s has come what sociologists call the accreditation society. A society where you can't really do very much in the new knowledge economy if you don't have qualifications," he said.
At the same time, comprehensive schooling opened up opportunities in the expanding further and higher education sectors.