The work of the McLellan Commission, which will investigate how the Catholic Church in Scotland handles abuse, was launched yesterday with some robust words from its chairman Andrew McLellan.

Dr McLellan, a former Moderator of the Church of Scotland and also a former chief inspector of prisons, said he hoped the Catholic Church would realise that it had no alternative but to change its culture. "The only credible policy for a church," he said, "is 'no abuse, no cover-up'."

As a statement of intent for an important investigation, Dr McLellan's words are a positive start, although the commission may end up being defined more by what it does not do as by what it does. The commission does, for example, intend to speak to survivors of abuse, but does not intend to re-open historic cases of abuse. That is likely to be frustrating and upsetting for survivors who feel they are still pursuing justice, although the commission has promised that, should it become aware of any crime, it will be reported to the police.

Instead of such historic cases, the focus of the commission will be the culture of the RC Church in Scotland, and on this there have already been some signs of hope. When the Fort Augustus boarding school abuse broke last year, the Church responded swiftly, offering an apology and promising to act, in sharp contrast to its reaction to the revelations of abuse in the Poor Sisters of Nazareth homes in the 1990s. Those claims were greeted by denials and the suggestion that the victims were tempted by the promise of compensation. The extent to which Dr McLellan and his commission can influence this continuing process of change will be limited and will depend on the influence of other parts of the Church all the way to the top. Profound cultural change has to come from the leadership and, on the issue of abuse, Pope Francis has, perhaps, been too defensive.

However, it is promising that the Catholic Church in Scotland has appointed Dr McLellan and appears willing to look outwards to learn lessons. The members of the commission also represent an impressive breadth of experience from the police, law, politics and social work.

The importance of its work is also beyond question. The Catholic Church is responsible for the care of thousands of children and vulnerable people across Scotland. But, in looking at this valuable work, what the commission must avoid is buying into the idea the Church should be subject to different rules. In fact, what is required is change fully to adopt a culture that applies everywhere else; one based on the principle that anyone who learns of abuse should pick up the phone and call the police right away.