SCOTLAND without the Enlightenment would be a country without its brain and its senses. You don't need to know a single sceptical line of David Hume's, nor how Adam Ferguson came to devise the idea of civic society, nor even to tell a Ramsay from a Wilkie, to be aware that the last three-quarters of the 18th century in Edinburgh turned a poor, feuding country of lost ambitions into a place of intellectual verve and style. It was one of the great revolutions.
By the time the American colonies were writing a democratic tract for the New World, and before France had set continental Europe ablaze, Scotland was already looking forward to a new age. As if Culloden and 1746 had truly been the miserable end of a
long epoch, there was a search for confidence in what was to come, what hadn't yet been discovered or even thought.
Just as imperial adventures were opening new vistas and conquests that glittered with opportunity, so Scots at home were beginning to build the pathways to modern society.
Hume's empirical dissection of how we reason and how we feel - and his understanding of how an individual is shaped by the world around - was a feat of sheer brilliance. Ferguson foresaw the battle between liberty and tyranny that would come with social "advancement". Adam Smith, that much-abused thinker who has been hijacked so often for passing purposes, looked into the future of the merchants' world that was expanding around him.
And alongside them, poets, painters and architects gave these ideas a physical expression that would last. Out of the ferment of the Old Town in Edinburgh came work that would be the personality of a New Age. As well as intellectual guts, it had a splendour that dazzled Europe. Even as they looked beyond the seas for new fortunes and new power, it was in old Edinburgh that they sensed a second renaissance.
Unionists and nationalists argue still about the nature of the irony that seems embedded in the self-confidence that welled up in the years after the Act of Union, because the moment when a country decided that its material interests lay in absorption in a bigger state seemed also to be a trigger for the beginning of a spiritual and intellectual resurgence.
But wherever you stand in the constitutional argument, the evidence of what followed is overpowering. Nothing like it had been seen, I suppose, since Florence was at the flood in the middle of the 16th century. Edinburgh was teeming with argument, experiment, confidence. The New Town was taking on a wondrous shape and would grow for decades, until the money ran out somewhere along Saxe Coburg Place in the 1830s.
Walter Scott, who had learned philosophy at Hume's feet, was fashioning a historical picture of Scotland which, however unfashionable it might one day become, was a blazing testament to the country's recovered sense of itself.
This was no fashion, but a movement. Though poets like Robert Fergusson, who so influenced Burns, were trying to express an idea of an older Scotland - perhaps one that wasn't going to be swept away by the changes that were transforming the cities and the land - the thrust of the age was forwards. Even in an ordered society which would retain its ability to defend and strengthen its bastions for many generations more, this was a time of radical thought. Nothing was impossible, nothing unthinkable.
The idea of progress itself, the engine of Victorian prosperity and self-confidence, came from the Scottish Enlightenment. The ideas that flowered in Edinburgh in the six or seven decades when the city was at its greatest were exported to the rest of the world and embedded in the new notions of democracy that would start to take root. The intensity of the philosophical debates that embraced Hume, Ferguson, Smith and the scientists such as Joseph Black and James Hutton would be felt for two centuries.
Their ideas were the sinews of Scotland at its best, bent on excellence and self-improvement and bold enough to face the world with a steady stare. That gaze, which understood how reason and feeling are intertwined and which looked forward with excitement to new worlds and new societies, has never seemed so confident since.
There is nothing of which we should be prouder.
• James Naughtie is a radio and television presenter, best-known for his work on Radio 4's flagship morning programme, Today
