At the end of the ’70s, Justin Welby left Cambridge to begin his career in Paris: ‘All the senior people said, “I can understand why you’ve come. There’s no future in your country any more.”’

Can he see now, though, looking back from our technicolour age, some kind of comfort in the half light? Some gloomy certainty about who we were that we miss in modern times? I have become a ’70s revisionist, at least to some extent. Something about the solidarity attracts me. The belonging – to union, even to class. To the mass audience for Morecambe and Wise.

The Archbishop is unconvinced. What about the football hooligans, he asks? The appalling racism. The treatment of women. ‘The people talking on the news from the ’70s – you think, “I can hardly listen to this, it’s so awful!”’

And social class? My mother had a peculiar array of things lower-class people were associated with: begonias, semi-sweet wine, eating in public, saying ‘perfume’ rather than ‘scent’, stressing the second syllable of the word controversy – on and on it went. And yet when people kept to their class she rather liked them for it, even if they said ‘toilet’ and ate with their mouths open. She felt superior but never antagonistic to those who knew their place.

Now I am not arguing her case but the advantage, I think she would suggest, is that when life goes wrong for you – as it inevitably does – there are still excuses under the old British class system for your personal failure. One of her favourite Peter Cook sketches was the miner sitting on a bench regretting that he didn’t ‘have the Latin, to do the judging’.

If you truly are free to go where your talents take you and you still go nowhere, who is to blame for that?

Welby dodges this by answering a different question. Never mind the freedom not to have to blame yourself for your failings, ‘Don’t we want the freedom that people from any background should be equally respected? Just think of how we treated race or gender: if people didn’t fit in they would be beyond the pale.’

To bring home his point he quotes, with a grimace, the old and now banned verse of All Things Bright and Beautiful: ‘The rich man at his castle, the poor man at his gate. God made them, high or lowly and ordered their estate.’

Neither of us sang that verse at our respective boarding schools in the ’70s, but we knew it was there. Part of the disorder of that decade was saying goodbye to those certainties without quite knowing what was around the corner. The Archbishop is sure about where we have landed: surer than me, I think.

He is also sure about the place that conscience has in our actions, even when our beliefs cut across the workings of democratic government. My mother refused to pay a portion of tax because it funded the buying of weapons that she regarded as immoral. She wrote a letter to the Inland Revenue informing them and they wrote a rather sweet letter back saying it was fine because she didn’t earn enough to pay tax so they were all square.