He's not only been called the first sociologist, but the first economist, too. That's when he's not being compared with everyone from Karl Marx to Machiavelli, Charles Darwin to Aristotle.
Ibn Khaldun's ideas have cropped up in Frank Herbert's well-known science fiction novel, Dune, and Facebook co-founder Mark Zuckerberg made his masterwork, The Muqaddimah, one of his books of the year. So who is this North African genius who has become such a hero to so many?
"Oh, just the most famous, profound and widely admired intellectual the Arab world has ever produced," says Robert Irwin, who has just written a new book on the 14th-century thinker, historian, teacher, judge and mystic. "But yes, all sorts of claims have been made of Ibn Khaldun and his influence – it's as if he's managed to step out of medieval North Africa and become a modern European."
The legend – and myth – behind Ibn Khaldun is, however, part of his appeal. Irwin himself likens him to an alien arrived from another planet.
For the uninitiated, the short version of his journey to such exalted status is this – born in Tunis in 1332, Ibn Khaldun spent his early adult years dabbling in law and politics and dealing with Arab tribesmen. In 1375, he started to write The Muqaddimah, which attempted to be a study of universal history, politics and civilisations, but also took on biology, chemistry and theology.
Largely ignored in his lifetime, it was only 300 years later that Ibn Khaldun was picked up by Orientalists and became fashionable in European circles. Ottoman intellectuals, worried about the possible decline of their empire, wondered whether they could find a solution in The Muqaddimah.
By the 20th century, Ibn Khaldun's ideas were feted by anthropologists, ethnologists and political theorists across the world.
What Irwin's new book aims to do in part, however, is to query the conclusion that Ibn Khaldun was a modern man way ahead of his time, with important things to say about the way we live in the 20th or 21st centuries. That might sound a little dispiriting, but Ibn Khaldun: An Intellectual Biography revels in a very 14th-century world view.
"I think he's interesting because he's so strange and medieval," Irwin says. "Obviously he's a genius, with a very powerful mind that liked to investigate every single available subject in his time. But what's more interesting about his writing is that it shows just how differently people used to live and think.
"He can be very logical. Yet great man though he was, some of his ideas were completely loony. I mean, he says that Alexander the Great wouldn't have gone in a submarine to confront sea monsters … because he would have got too hot. He got his science a bit mixed up there."
But the talk of sea monsters and djinn in The Muqaddimah is important because although Ibn Khaldun operated right on the borders of what could properly be understood – both then and even now – he could also be very conventional.
He was a Malaki Muslim who articulated the ideas, prejudices and religious beliefs of 14th-century Moroccans. The Muqadimmah is, Irwin says, prone to moralising and has a basis in religious law.
"He was a judge and taught Malaki law, and reapplied that to his reading of history and whether events are likely to have happened or not," he says. "Rival historians tended to quote great chains of witnesses but Ibn Khaldun's insights are determined on what he had read in the Quran.
"So his world had much more in common with the Quran and The Thousand And One Nights than it does with modern historiography or sociology – and that's why the contrasts with our world in Ibn Khaldun's work are more interesting than the comparisons."
Irwin has been studying Ibn Khaldun since the 1960s – when some of the analysis had begun to veer towards the more patronising side of Orientalism. So he's pleased that many of the most scholarly studies in recent decades were produced by Arabs – so much so that Irwin was reticent about adding yet another book to the Ibn Khaldun bibliography. But the author's arguments are so persuasive, it might just be the definitive work – for now. It is certainly the least hagiographic, even if that means at times it can be a little academic.
But then, that's the problem with Ibn Khaldun – it's almost impossible to glean much about his character beyond his theories. Muqaddimah translator Vincent Monteil, a fully signed up member of the "Ibn Khaldun invented sociology" school, had to resort to astrology to try to understand his hero – Ibn Khaldun was a Gemini, so "subtle and curious and capable of combining reason with imagination". But, to be fair, that seems as apt a description as any. "That astrology-based suggestion by Monteil always makes me laugh, simply because it recognises how difficult it is to get to know him," Irwin says. "Clearly, Ibn Khaldun was aloof, stern, uncompromising, fond of literature. But the conventions of the time meant people were so secretive. Like many other Arab intellectuals he wrote a kind of autobiography, but he never mentioned his family life, his wives and so on. We don't know what he did for pleasure, if anything. He is an enigma."
Even his mystical beliefs are confusing. Irwin says that it is pretty clear from the way Ibn Khaldun writes about Sufism that he was a Sufi, but he never says so, or directly refers to a mystical experience.
So we are left, instead, with the weight of his ideas. And, perhaps because they are set apart from his character, it has been all too easy to cut and paste certain facets of his books and ignore some of the sheer strangeness of his thinking. Here’s another example – he genuinely believed people could live without eating.
Still, Ibn Khaldun is undergoing another renaissance in the 21st century. His thoughts on the decline of civilisations as they become too accustomed to luxury, strike more than a few chords with those who have a more pessimistic view of history – or indeed the future.
“I hadn’t thought of it like that but it is an interesting notion,” Irwin says.
“Certainly people who studied Ibn Khaldun have tended to be of a pessimistic frame of mind. There’s a kind of romantic embrace of the glorious pageantry of the past.”
Irwin's argument that it is Ibn Khaldun's "irrelevance" to the modern world that makes him so interesting is, then, remarkably similar to Mark Zuckerberg's two paragraph review of The Muqaddimah. "While much of what was believed then is now disproven after 700 years more progress, it's still interesting to see what was understood at the time and the overall world view," Zuckerberg says.
“I really want people to realise the strangeness of the past and the nature of history – and history writing,” Irwin says.
"As L P Hartley once memorably wrote in The Go-Between: 'The past is a foreign country; they do things differently there'."
Ibn Khaldun: An Intellectual Biography by Robert Irwin and published by Princeton University Press is out now