Ex-chancellor George Osborne is planning a book to be titled The Age of Unreason. He says that ‘it will be my attempt to understand why populist nationalism is on the rise in our western democracies’. An Athenian would have been most surprised by that title’s implications.

If the ancient Greeks are famous for anything, it is for the invention of western ‘philosophy’. By that is usually meant the attempt to explain the world in humanly intelligible terms, i.e. by the exclusive use of reason and evidence, without calling in aid the supernatural. This sort of thinking, begun by eastern Greeks in the 7th century BC, reached something of an apogee (at least in the eyes of most later generations) in 5th- to 4th-century BC Athens with Socrates, Plato and Aristotle.

Further, these thinkers did not just debate among themselves. They fought it out in public on the big issues of the day — everything from the nature of gods and the universe, to how best to run a state or lead one’s life — and the populus joined in. A few thinkers, like Socrates, paid a high price. But their influence down the millennia has been profound.

But Athens in its ‘age of reason’ was also in the grip of extreme populist nationalism. Its ‘populism’ was absolute. Citizens, meeting weekly in Assembly, were sovereign, and there they joined in debates on every political issue put before them, reaching decisions by a show of hands. If that is not bad enough, the Athenians were at the same time enjoying a golden age of nationalist triumphalism, having driven off the Persian menace in 479 BC and being currently engaged in building up a maritime empire that threatened to control the Aegean and much of Greece.

So if Mr Osborne wishes to argue that there is a link between ‘unreason’ and ‘populist nationalism’, he might reflect on classical Athens and wonder where the ‘unreason’ lay in a vigorous public debate resulting in the people voting for a Britain able to decide for itself where its own interests lay.