As the chatter of the seated audience increases in anticipation, I am huddled in the corner of the lecture theatre with tonight’s guest speaker, AC (“call me Anthony”) Grayling. He’s about to address the newly-revived Atheist, Secularist and Humanist Society in the Cavonius Centre inside the Stephen Hawking Building. The atmosphere, appropriately, is that of a new-age Athenian Academy.

With his round-frame glasses and swept-back silver hair, Grayling plays the part of sophistai well. As I am to find out immediately after our interview, he is also a fluent public speaker who has no need for notes. He addresses the audience on the history of religion and its continuing institutional power, keeping the audience in tow despite humorous digressions into personal anecdote. The audience is reminded that Anglican bishops continue to influence politics through their privileged positions in the House of Lords, making Britain something of a theocracy. “But I know irony is dead now – Brexit and so on”, he remarks casually, and the audience are in fits.

But I’m not here to ask him about his atheism - that’s home-turf. If the best political treatises are forged in the heat of political crisis, then the past few years have something in common with the last decade of the 18th century in France, or the mid-17th in England. These were not just times of political confusion, but moments of intense theorising (and good news for publishing houses). Indeed, the past couple of years have produced Runciman’s How Democracy Ends, Klein’s No is Not Enough and Grayling’s own Democracy and its Crisis. A glance at any Waterstones non-fiction bestsellers board and you’d be forgiven for thinking that our democracy was collapsing, and our intellectual class were worried about it.

“But I know irony is dead now – Brexit and so on”, he remarks casually”

As it happens, British democracy is collapsing – according to Grayling. The British people have voted for self-destruction (apparently), and Grayling now seeks to explain why the democratic process has come up with such badly wrong answers. “Referendums should not be taking place in a representative democracy”: this is the gambit of his book, and the perfect intervention to make on the very day the PM was defeated in the Commons for a second time, and the revocation, or at least the extension, of Article 50 became that bit more likely.

“We’re in a crucial week as we speak. Because there are so many factions in Parliament there are a few ways out of the dilemma: one of them is to revoke Article 50, and the other is another referendum.”

Can a popular vote be used to reverse a popular vote? Or in Grayling’s formulation, can two wrongs make a right? “Because we have in our constitution the doctrine of the sovereignty of parliament, nowhere does it say that the referendum is binding. It is up to the House of Commons to decide whether they are to accept the advice of a third of the electorate.”

This line of argument is taken up in in more detail in Grayling’s book. According to its appendix, the Brexit vote was “gerrymandered” from the start, and little more than a “coup” for a motley crew of Eurosceptic Tories. Grayling rehearses some of the key points to me.

“Of the electorate that was enfranchised for the referendum, only 37% voted to leave, which constitutionally is nonsense. Trade union law in this country says that at least 40% have to vote for a strike to be legal. 66% of members of the House of Commons have to vote in favour of the dissolution of Parliament before an election.”

“The problem for Grayling is that we’ve lost sight of what our constitution was set up to do”

I have to stop him at this point to clarify something. The 37% figure includes those who chose not vote. Why he chooses to include in his tally those who did not involve themselves in the referendum either way confuses me. This process brought more people to the polling booth than any general election since 1992; and we’ve been happy, constitutionally speaking, to take less conclusive results when electing our own governments: the Conservatives formed a majority (albeit a slim one) in Parliament on just 36% of the vote in 2015.

So what’s the deeper question? The problem for Grayling is that we’ve lost sight of what our constitution was set up to do. Referendums are appropriate to a direct democracy - the sort seen in ancient Athens. Our democracy, a scaled-up version of the classical city-state, is a “compromise” which checks against the tendency for popular systems to err towards mob-rule.

“That’s why we have Parliament - we send people to Parliament to do that work for us.”

Unfortunately, our constitution is also very fickle. “If we look at all the referendums that have happened since 1975 we notice something astonishing about them. They have all been run on a different basis.”

The Scottish Independence Referendum, perhaps a question of equal constitutional significance, was opened to 16- and 17-year olds, and only in Scotland. The 2011 Alternative Vote Referendum, unlike the EU Referendum, was mandatory rather than strictly advisory. “The problem we have in this country is that because parts of our constitution are uncodified, it means that governments often make it up as they go along.” In this case, Grayling argues that the youth vote was strategically squeezed out to fulfil the Eurosceptic prophecy. What about the Gibraltarians - should they have had a say on Brexit?

“The perfect constitution, then, is a Goldilocks constitution - not too rigid, but not too flexible either”

Yet when discussion turns to US politics, it seems that things are scarcely better. Across the pond, a codified constitution outlining strict divisions of powers has recently resulted in the longest US government shutdown in history.

“The problem with the American Constitution is that it has the sacredness of holy writ. Sample the right to bear arms. That amendment was written in the 18th century when there were muzzle-loaded muskets. It was not for Kalashnikovs and assault rifles. The fact that the United States can’t remedy that is bizarre.”

The perfect constitution, then, is a Goldilocks constitution - not too rigid, but not too flexible either. It should be codified but “provide means for refreshing and repealing itself from time to time.”

Grayling is explicit about his partisan intentions, noting of recent developments that he “would be delighted if the whole thing didn’t happen.” And there’s little doubt that Grayling’s ideal constitution requires its own form of “gerrymandering”. He declares, with peculiar specificity, that the Leave campaign required an additional 1.2 million votes on top of its 1 million majority to become fully legitimate. That’s based on his trade union analogy - a 40% turnout in favour - but one suspects that the analogy is as fragile as the vote itself. One could also question his level of analysis - does the focus on intra-party squabbling not ignore the wider forces which made Brexit possible?

Constitutional quibbles aside, though, we can both agree on some of the bigger picture. In the conclusion to Democracy and its Crisis Grayling attempts a bold synthesis of the moral and the political. This is more than just a debate about Commons Briefing Papers and electoral regulations, he argues: democracy is a fight for the soul of the citizen. It starts in the school, and struggles on with every conversation between friends and families. Grayling offers two bold remedies to a current sense of democratic malaise: a compulsory curriculum of civic education and compulsory voting. We are reminded, nonetheless, that “one can do no more than take a horse to water.”

Grayling believes in the engaged philosopher, and his arguments come at a crucial junction in Britain’s political conversation. I have little doubt that the problem of democracy will continue to inspire in him bouts of disbelief in the months to come. His legalistic case to pack the whole Brexit thing away seems, however, to be either too little too late to his supporters or outright patronising to his opponents (but the current drama may invalidate those words in the next few days). Aristotle once praised the “wisdom of the multitude” – it remains to be seen whether that doctrine will be revised after this historic moment and, if so, by whom.