My Edinburgh International Book Festival week began with a religious revivalist meeting.

Journalists Polly Toynbee and David Walker used a ritualized call and response to out the devil and all his works. Their devil is Prime Minister David Cameron who, though routinely underestimated by his own dark angels, is even more of an ideologue than the previous devil-incarnate Margaret Thatcher. Cameron's Britain is profits for the few, zero-hour contracts for the many, ever diminishing public services and so on. Toynbee and Walker believe that the only way out is via a new religion called Milibandism. Articles of faith include the saviour being elected next year (not a cat's chance in hell according to a heretic in the audience), ditching everything that currently echoes the Tories, and ushering in a new age of wealth redistribution and decentralisation of power.

Another faith was briefly referenced but anybody who believes in Scottish independence as a remedy, they reckoned, should give up now. Scotland is too wee, too poor and too stupid to address any of this by itself and, to demonstrate this inadequacy, Walker referred to a series of statistics on inequality, life expectancy and land ownership. My Catholic upbringing obliged me to note the sin of omission: there was no mention of the relationship between 50 years of Labour hegemony in Scotland and the conditions that Walker and Toynbee consider so debilitating.

It was all too much for the "temporary neutrality" of journalist/chair Ruth Wishart. In a strange echo of Cameron's "Scottish bloodline", Toynbee said she was "part Scottish" to which Wishart responded "not that you would notice". At this point I had an epiphany. The session wasn't really about a new religion at all but about an old club and we were simply being patronised by a different branch of it. The revelation that Toynbee had seen Boris Johnson naked when he was a baby produced a cry of "Hallelujah", though only inside my head.

"The Reinvention Of Britain" with historian Linda Colley was an altogether more sober affair. Colley has a faithful following among professional and amateur historians, and much of what she has written about Union as a product of war and on multiple identities is familiar. The possible demise of that Union should not be seen just in terms of Scottish independence, Colley argues, but in the broader context of the rise of Asia, the relative decline of the United States, problems in Europe and "above all, global warming". Challenges need "collaboration across boundaries" though she later modified that by saying that if what's left of the UK after independence is out of Europe in 2017 she would be "clamouring for Scottish citizenship". Colley believes Britain needs a written constitution and an English parliament as part of a federal future if there is a No vote.

Former Scottish First Minister Henry McLeish and political commentator David Torrance also turned out to be men of faith during a session entitled "Yes Or No, What Next?" McLeish is a self-declared optimist who believes that Scotland "will be great" regardless of which way the vote goes in September. Torrance is a "born again federalist" who thinks that Britain has been a "quasi federalist" state since 1999. Why not build a federal system deliberately, he asks, "when it is happening anyway"?

McLeish thinks that the Union has "outlived its usefulness" but is more vague than Torrance on what should be done beyond a grand meeting of the minds after a No vote. McLeish's experience as a practising politician eventually undermined Torrance's vision of the future. His involvement in the devolution process revealed a lack of interest in Scottish affairs in London and federalism is "not even a blink in the eye of the smallest eye at Westminster". By the end, all was confusion with Torrance continuing to make a logical case for the never-happening and McLeish arguing for a Yes vote - "of course there will be a currency union, of course Scotland will be in the EU" - while pretending not to.

Chair Allan Massie introduced novelist James Robertson with the "very important point" that his book The Professor Of Truth is "imagined". He encouraged the audience to bear this in mind when listening to a reading from it. In the reading, a protagonist who has lost a loved one in an act of terrorism resembling the Lockerbie bombing begins to doubt the subsequent conviction. Massie immediately ignored his own direction on imaginative literature and pursued Robertson on matters of fact. The novelist was asked about the Scottish legal, policing and political systems and, bizarrely, whether he agreed that the British Empire was a force for good.

When Robertson did get a chance to talk about his craft - as in an interesting reflection on the difficult balance between historical research and novel writing - it was halfheartedly pursued by Massie who appeared to be at the service of some other agenda. I was left wondering if Scottish writers were always expected to know something about everything or if this is some kind of unintended consequence of the independence referendum. Right on cue, an audience member asked if Singapore was a good model for an independent Scotland. Robertson's good nature had previously obliged him to have a go at everything but even he drew the line at that.