David Hume and Thomas Aikenhead

A man in a toga, 1.5 times life size, sits at the junction of Edinburgh's Royal Mile and George IV Bridge, more interested in his tablet than in St Giles Cathedral opposite - 'the mother church of presbyterianism'.

The man is David Hume, philosopher, historian, civil servant, founding father of the enlightement and one of the most influential Scots of the last millennium. Small wonder that he has no interest in St Giles, for Hume was an aetheist.

On 23 April this year, to mark the 300th anniversary of Hume's birth, a colourful parade will leave the Scottish Parliament and march up the Royal Mile to this statue.  The celebration will start by re-enacting the notorious 1696 trial of an Edinburgh student, Thomas Aikenhead, the last person in Britain to be hung for blasphemy. Aikenhead's story will be familiar to readers of Arthur Herman's book, 'How The Scots Invented the Modern World', since a discussion of the case forms the Prologue.

The parade will pass the Old Tron Kirk, a little further down the High Street where the 18 year old Aikenhead made a poor joke about the weather, 'I wish right now I were in the place Ezra called hell to warm myself there'. This flippant attitude to the Bible was the lad's undoing. You might call it a fatwa called by Scotland's Lord Advocate and chief law officer, James Stewart, to discourage others from treating the Bible with disrespect. Years later, Hume was utterly apalled.

I am not an aetheist but I may be there on 23 April to celebrate Hume's extraordinary pioneering thinking.

Hope the weather isn't hellish.