Catherine is not the wishy-washy kind of Presbyterian who might suggest that all faiths are just the same, really, when you get right down to it, and I’m not the kind of Catholic who can hear such twaddle with equaminity. Cath will joyfully argue for Presbyterianism until she is hoarse against the kind of Catholics who live and breath Catholic apologetics. I, however, was not trained in apologetics but in avoiding arguments with my Presbyterian granny. And at theology school, I was told to emphasize commonalities in ecumenical dialogue. Thus, when presented with a non-Catholic, I begin to snuffle around for commonalities like a pig searching for truffles.

The difficulty there is that I don’t actually know that much about what we now call “the Reformed traditions.” For one thing, there are so many of them. And for another, I don’t really have the time to find out. At Regis College I would horrify the ecumenical-minded by saying I wouldn’t take courses at the “Reformed tradition” schools as I wasn’t interested in learning heresy and error. It did not occur to me — as it did after I went elsewhere — that you can learn plenty of heresy and error from so-called Catholics, too. In fact, it turns out that some Reformed traditions contain many Catholic beliefs that some Catholics betray.

Take, for example, the idea that there is no distinction between clergy and laypeople. The Catholic Church believes and teaches that there is certainly a distinction between clergy and laypeople, and yet in recent decades there has been a movement in the Church to erode this distinction — with, I might add, a corresponding drop in vocations to the priesthood. And the erosion of the priesthood is surely not anything a Catholic would want. The whole idea seemed to me — wrongly, as it turns out — suspiciously Protestant.

For there I was in an Edinburgh café with Cath as the conversation turned to religion. Cath knew of a baby to be baptized, and she was concerned that it would be baptized by the wrong person.

“Well,” I said, “surely that doesn’t matter in the long run, just so long as the baby is baptized.”

Cath said that it did too matter. For one thing, the baby had to be baptized by an ordained minister.

“Oh,” I said. “Um — really? Because we Catholics believe that in an emergency it doesn’t matter who baptizes you, as long as they have running water, and say the right formula and intend what the Church intends. Technically, you could be baptized by a Muslim with a puddle.”

Cath disgreed happily, which left me with the startled impression that this strict Presbyterian, whose understanding of sacrament was clearly different, placed even more of a distinction between ordained ministers and laypeople than Catholic I did. I sent her an e-mail asking her to explain.

“Only ordained ministers have the power of the keys, which includes the right to administer the sacraments, of which Baptism is one,” she wrote. “It doesn’t necessarily have to be a Presbyterian minister though — baptisms are still valid if they’re performed by Anglicans or Lutherans or even Baptists. There is a minority/fringe view that Baptism isn’t valid if it’s performed by a Roman priest, which has been held by some serious theologians in the past, but it remains a fringe view. The dominant view is that it is not necessary for converts from Rome to be re-baptised.”

I grimaced a bit at the very low-esteem in which “Roman priests” have been held by the Reformed tradition and went on to read a Presbyterian defence of clergy by William Cunningham, a 19th-century theologian of the Free Church of Scotland:

“The apostles and elders, or presbyters — i.e. the office-bearers of the Church — alone composed the Council (of Jerusalem, in Acts 15); they exclusively were its constituent members, and they alone formally and judicially decided upon the point brought before them. … There is, indeed, a clear distinction kept up in the New Testament between the office-bearers and the ordinary members of the Church: the one class being invested with a certain kind and degree of authority; and the other being bound to render a certain measure and degree of submission and obedience.”

This is not, of course, a defense of the priesthood as Catholics understand it. But it does hint that if Catholics think they can use “Christian unity” as an excuse to erode the distinction between clergy and laypeople, they might be nailing their theses to the wrong door.