IT is not the least of the many mysteries surrounding James Burnett, Lord Monboddo, that we do not know the exact date of his birthday.

We do know that the baptism of the great eccentric genius of the Scottish Enlightenment took place in this week of October 1714, and his birth is usually stated as being on October 25.

Burnett drew his ancestry from the famous family Burnett of Leys. He was born to the Burnett owner of an estate in The Mearns in what was then Kincardineshire. Monboddo House still stands and indeed it was superbly restored in 2006.

It appears his parents were not vastly wealthy but were able to have him educated at Marischal College, Aberdeen, where he came under the influence of another major Enlightenment figure, Professor Thomas Blackwell, who instilled in him a lifelong love of Greek philosophy. One of his best works in later life was Antient Metaphysics, which lauded Aristotle above all – it helped that Monboddo could read, write and speak ancient Greek and made his own translations of the philosopher’s works.

Burnett graduated at the age of just 15 and then went on to further studies at Edinburgh University and the University of Groningen where he studied law.

Basing himself in Edinburgh, Burnett became an advocate in 1737, and combined his long career in law with scholarship of considerable quality, as well as becoming a leading figure in Edinburgh society at a time when the Scottish Enlightenment was getting into full swing.

That he was genuinely eccentric is well attested to. His published works include references to tribes with just one leg, while others had only one eye, and he certainly believed in mermaids.

Stories abounded of his strange manners. He once came out of court and, finding it raining, he hailed a sedan chair and had his wig carried home while he walked alongside. Every summer he rode to London, refusing to travel by ship or carriage.

In 1754, he co-founded a theatre in the Canongate – this at a time when the Church of Scotland frowned on such things. One of the actors in the theatre was the man generally reckoned to be one of the world’s great philosophers, his friend David Hume.

There was no doubting Burnett’s legal prowess. Having been appointed Sheriff of Kincardine in 1760 he was appointed a judge of the Court of Session in 1767 and took the name Lord Monboddo, after his family home. It was after he became a judge that Monboddo virtually founded the science of comparative historical linguistics with his book Of the Origin and Progress of Language.

Published in six volumes, Monboddo argued that structure of primitive and modern languages showed that mankind evolved language skills in response to his changing environment and altering social structures. In doing so he drew on studies of languages across the globe, and one of his most startling theories – since proved – was that peoples then classed as primitives actually used longer polysyllabic words than so called educated societies, demonstrating the differences in linguistic development.

As Encyclopaedia Britannica states: “Burnett was the first to set out what we today call the single-origin theory, the suggestion that the human species began at a single place and time. Many feel that through his work on linguistics, Burnett was among the first to express views that were later developed by Charles Darwin in his theory of evolution.”

He certainly did put forward the view that men and apes were related, decades before Darwin wrote Origin of the Species, though the problem for Monboddo was that his book – possibly as a joke – suggested men had tails that were cut off by midwives.

Bertrand Russell in his History of Western Philosophy states: “As a rule, the man who first thinks of a new idea is so much ahead of his time that everyone thinks him silly, so that he remains obscure and is soon forgotten. Then,

gradually, the world becomes ready for the idea, and the man who proclaims it at the fortunate moment gets all the credit. So it was, for example, with Darwin: poor Lord Monboddo was a laughing stock.”

Nevertheless his house at 13 St John Street was always filled with learned people, such as Hume and Robert Burns on his various visits to Edinburgh. No wonder Rabbie loved it there, as the table was strewn with roses and the wine always plentiful.

Monboddo’s second daughter by his wife Elizabethe Farquharson was Eliza, a noted beauty whose death from tuberculosis, or consumption as it was then known, at the age of 25 inspired one of Burns’s best-known elegies.

Burnett himself died in 1799 and is buried in Greyfriars Kirkyard in Edinburgh close to his daughter Eliza. Shortly after Darwin’s Origin came out, Blackwoods magazine carried a poem about Monboddo.

Though Darwin may proclaim the law,
And spread it far abroad, O!
The man that first the secret saw,
Was honest old Monboddo

Perhaps we should revisit Monboddo and give him more credit.