It would take a "seismic" event in England to swing the Scottish vote in September to yes to independence of the UK.

A global economic crash has not been enough to swing it so far and David Torrance speculated that, even were David Cameron to write an article entitled Why I Hate Alex Salmond, it would be unlikely to be enough to nudge the no outcome.

Torrance – Salmond’s biographer, The Herald journalist, and broadcaster on constitutional affairs –shared his erudite and historical essay on the background to the debate, captured in his newest book’s title The Battle For Britain.

He was passionate, not without humour, and quoted at length from writers as diverse as Marx, Philip Larkin, Voltaire, Alex Salmond, David Cameron, Bevan and William McIlvanney.

It was difficult at times to take it all in. While an unquestionably comprehensive, thorough and intelligent analysis of elements which lay behind the referendum, the richness of his argument made it quite difficult to listen to for more than 40 minutes.

The level of address presupposed members of the audience had more than just an interest in the question. Notably, there was no straight answer to who is going to pay for it all.