Two men go head to head in a TV debate. They wrestle with Britain’s relationship to Europe, the meaning of sovereignty, the nature of global influence, the question of job losses. They listen carefully to each other and respond to the other’s points, fierce in defence of their arguments, but reasonable towards their opponent. It’s an illuminating discussion that makes one appreciate the issues more deeply.

No, not last week’s TV spat between Boris Johnson and Jeremy Corbyn (as if!) but an hour-long debate on BBC’s Panorama more than 40 years ago between Tony Benn and Roy Jenkins in the run-up to the 1975 referendum on Britain’s membership of the Common Market. Both were cabinet ministers in Harold Wilson’s government, Jenkins an ardent supporter of membership, Benn a passionate opponent.

What is striking about the debate is that it could have taken place last week – the issues at the heart of the Europe question have changed little over that time. What is striking, too, is that the 40-year-old encounter is more illuminating, on both sides, than most discussions we have had since 2016.

Comparing the old Benn-Jenkins tussle with current political debates shows not just how shallow and vapid politics has become, but also how politicians’ expectations of the electorate have been transformed. Benn and Jenkins took their audience seriously and so considered their arguments, and those of their opponent, with care.

Today, political debates have become vacuous and insipid because politicians have become contemptuous of the electorate. Voters, many believe, are ignorant, swayed more by emotion than by reason, happy to accept lies and drawn to politicians with easy answers. So politicians prefer slogans to reasoned argument, dismiss scrutiny as “partisanship” and treat truth as if it were a form of entertainment. It’s an approach rooted in a caricature of the electorate. It’s also one shaped by a shift in the relationship between working-class voters, education and politics.

In his magnificent book The Intellectual Life of the British Working Classes, Jonathan Rose traces the struggles of working people to educate themselves, from early autodidactism through education reform to the Workers’ Educational Association and the Open University. Drawing on memoirs, diaries, oral history and social surveys, Rose provides “an intellectual history of people who were not expected to think for themselves”.

The miners’ institutes of south Wales, funded initially by a levy on wages, became “one of the greatest networks of cultural institutions created by working people anywhere in the world”. By 1934, there were more than 100 miners’ libraries in the Welsh coalfield with an average stock of 3,000 books.

Such reading provided not just cultural ballast but political hope, expanding horizons limited by the factory or mine

Another triumph of the autodidact tradition was the Everyman’s Library, launched in 1906 by J M Dent, the 10th child of a Darlington house-painter, who left school aged 13, became a bookbinder and eventually a publisher, whose dream had always been to ensure that “for a few shillings the reader may have a whole bookshelf of the immortals”. Everyman’s Library did not publish just obvious works that might appeal, such as Dickens or Shakespeare, but such “lengthy and intimidating” works as George Grote’s 12-volume History of Greece and six volumes of Ibsen, all of which found a ready audience. Such reading provided not just cultural ballast but political hope, too, revealing the possibility of new worlds, and expanding horizons that might have been limited by the factory or the mine. “The Labour movement,” a Coventry millworker observed, “grew out of mutual improvement societies.”

It was a tradition sustained by communities that helped cultivate dignity, organisations that nurtured the spirit of self-improvement, collective struggles that enlarged the range of the possible. Much of that has disappeared. The dislocation of working-class communities, the destruction of Labour movement organisations and the expunging of trade union struggles have all unstitched the relationship between knowledge and political change.

Education today, as the political scientist David Runciman has observed, “sorts us according to where we feel we belong”. As western societies have become more technocratic, “empowering a new class of experts, for whom education is a prerequisite of entry into the elite” – bankers, lawyers, doctors, civil servants, pundits, academics – so knowledge no longer seems to “speak for itself” but “for the world view of the people who possess it”. Knowledge, instead, becomes a marker of the place one possesses in society. This has led one side to deride “experts”, the other to view the electorate as ignorant and incapable of deep reasoning.

That a 40-year-old debate is more clarifying about Brexit than one held last week reveals the degree to which politics has become hollowed out. We should take care that the contempt shown to the electorate does not become a self-fulfilling prophecy.

• Kenan Malik is an Observer columnist