IT was a visiting Englishman, one John Amyat, the King's Chemist, who in the middle of the 18th century famously observed:

"Here I stand at what is called the Cross of Edinburgh, and can, in a few minutes, take 50 men of genius and learning by the hand." Mr Amyat was not exaggerating. "It was a period of prodigious thought," wrote Neil McCallum, some 200 years later, "prodigious work, prodigious discoveries". Edinburgh, with a population of no more than 40,000, was a city in ferment. As if to make up for the loss of its parliament and independence a few decades earlier, it transformed itself from a stagnant backwater into an intellectual hothouse, the like of which had not been seen since the Renaissance lit up Florence.

No sphere of human enquiry was left unstirred. Not only did the likes of Adam Smith and David Hume forge innovative ways of thinking, but also their contemporaries, such as James Hutton, the "father of modern geology", created sciences where none previously existed. In 100 astonishing years, they and their peers changed the world philosophically and materially and ushered in an era of unprecedented progress. Their names - Lord Kelvin, James Clerk Maxwell, Thomas Playfair, Adam Ferguson, William Murdock, Thomas Telford, the lighthouse Stevensons and many, many more - are the stuff of legend. The arts were no less prominent. James Boswell, for example, invented biography while Walter Scott gave us the historical novel. Everything, it seems, was up for grabs and nothing was taken for granted.

While we can easily reel off the luminaries of the Enlightenment, explaining why it came about is harder. It may have had to do with Scots' attitudes to education and learning and respect for scholarship. On the other hand, there may simply have been something magical in the ether. My own ill-informed view is that, in a close-knit place like Edinburgh, a great deal can be explained by competition.

No-one wanted to be outshone; everyone wanted to make his mark. Inevitably, the centuries since have been intellectually patchy. In the 1920s, Hugh MacDiarmid, one of several writers behind the movement which morphed into the Scottish National Party, thought Scotland was creatively moribund. His solution was another renaissance but such phenomena are rare and difficult, if not impossible, to prescribe. At present, as the day of judgment draws ever nearer, we are living in a period in which the gap between intellectuals and the ignorant is as wide as that between rich and poor.

Whether we vote Yes or No eight days from now, Scotland needs to decide what kind of society it wants. My own belief is that it must be one in which learning and unconventional thinking are placed at the top of the cairn. We need intellectually to up our game, to elevate any debate, be it on religion, foreign affairs or wind power, to the point at which we are not afraid to be serious. This is particularly true of the media which, post the hacking scandal, is struggling to define its role. The BBC is a case in point. Once the equivalent of an on-tap university, it dumbs down ever deeper in an attempt to be all things to all people. In so doing, it satisfies no-one and is in danger of self-destruction.

In Scotland, the independence debate has demonstrated that there is a thirst for knowledge and information. Across the country, public gatherings have been packed as policies and pronouncements have been tested. This meeting of minds has been one of the highlights of the campaign and shows that people are willing to be challenged.

In the 18th century, the focal point for that may have been the Cross of Edinburgh. What's its equivalent now? The Royal Society of Edinburgh is the nearest we have but how many Scots know of its existence, let alone what goes on behind its George Street facade? In the main, its membership is drawn from academia and its proceedings, while often open to the public, rarely enter the collective bloodstream.

Might this not be an opportune moment to inaugurate a Scottish Academy, the aim being to connect men and women of genius across the nation with others less gifted? It may not usher in a 21st century Enlightenment, but at the very least it would be a sign that its legacy endures.