BLASPHEMY is in the air in Edinburgh these days. Well, at least talk of it.

There's a slight hint of violence, too. If there's a rammy in the street with someone getting a kicking, it will either be (a) the capital's hoodies at play, or (b) the Free Church of Scotland and the Free Church (Continuing) encountering each other in fratricidal mode, maybe even turning on one of their own. Welcome to John Knox Central.

You can't travel any distance from the coffee houses of George IV Bridge without tripping over a Presbyterian general assembly. Aficionados can choose between the industrial-strength heart attack-inducing caffeine version of Presbyterianism of the FCC, the slightly mellower but still seriously temple-vein-throbbing espresso of the Free Church or the decaffeinated, fairly-traded Kirk latte at the top of the Mound, where, God bless him, John Knox wears a Make Poverty History armband.

Anyway, to blasphemy. The moderator of the breakaway group which claims to be the true Free Church of Scotland has criticised radio and television for promoting blasphemy.

The RevWilliam Macleod said blasphemy had always gone on but in the past it was in private and there used to be a measure of shame attached to it. Today nothing was sacred, said the Portree minister.

Meanwhile, the Rev Alex MacDonald, moderator of the Free Church of Scotland, said that people pinned the blame for a "devastated society" on Calvinism or Presbyterianism.

"You cannot blame John Knox for the catastrophic state of our nation today, " he said. "This is the postmodern world we are living in, formed by the scepticism of generations - a world that has lost its way, a world full of lost, confused and despairing people."

A big problem facing churches of all stripes, Protestant and Catholic, is that they are part of a European Christendom which is visibly dying on its feet.

Church leaders who used to be very influential in Scotland are finding it hard to adjust to their loss of authority. They are bewildered and angry at finding themselves no longer representing a religion which is privileged by the prevailing culture.

In the "good old days", people could be barbecued for blasphemy. Chestnuts roasting on an open fire, while orthodox voyeurs bayed from the same hymnsheet. We don't do much of the old eye-gouging and stringing-up nowadays, but, in theory, the state can still prosecute somebody for taking the name of God in vain. There are those who wish to reinforce these laws, and some want to extend their protection to other religions. God forbid. The blasphemy laws should be wiped off the statute book. God has no need of such defences, nor of his often fairly grizzly defenders.

The free market of ideas is to be welcomed. I find it intriguing, though, how religious concepts become bastardised and find their way in through the back door. So the idea of blasphemy has made its comeback.

It doesn't call itself blasphemy and it doesn't refer to God, but it brings in its wake the old ferocious sense of "You can't say that!"

While offending against the new secular orthodoxies does not bring the shadow of a scaffold, there are plenty of penalties. The language of political correctness is now so tight and taut that honest debate is often curtailed in the name of an ideological conformity which brooks no dissent.

I can best illustrate this shift in consciousness by talking about Billy Connolly. Some years ago, Connolly produced a brilliant religious satire on the Last Supper, set in the Saracen's Head pub in Glasgow. Offensive? Yes, but I suspect that even Jesus was laughing. Denounced as a blasphemer, the Big Yin was able to laugh his way through the controversy.

But when the comedian made a tasteless joke about a hostage in Iraq, the ferocity of the response was akin to the reaction to blasphemy in the Middle Ages. The new secular inquisitors were out in force.

Blasphemy is dead; long live blasphemy.

This is difficult and controversial territory. As a society, we rightly protect vulnerable minorities from verbal abuse, and we place a strong value on the concept of human rights.

But we are far from mastering the difficult balancing of these things with precious, hard-won freedom of speech.

Back to the assemblies. The Rev Alex MacDonald is right when he talks about a world full of lost, confused and despairing people. But this is also a world full of people who delight in being alive in the modern world. Many are both joyfully spiritual and glad to be free of the once-long reach of churches.

Forget the blasphemy lectures. Dismount from the moral high horse. What those of us who belong to the old churches need most is to get over the loss of archaic and disabling privilege, and get a life.

In the process, we may even learn a new vocabulary of grace, a fresh language of embodied spirituality which can blaspheme gloriously against the latest tiresome privileged dogmas and touch the human heart.