I catch the end of a TV programme about the art critic John Berger, who has turned ninety. He is lucid and at his desk, drawing flowers and making the point that form in nature, organic form, is not verbally expressible; a flower is not a text. As a Marxist influenced by Walter Benjamin, Berger was often infuriating. He took to task the painter Josef Herman – a Pole who lived for a while in the industrial valleys of South Wales – for not portraying coalminers as militant, an aspect of their character he deemed important. It might well have been (we talk in the past tense about coalmining in Britain these days), but taking issue with people for their acts of omission is a weak polemical stance. What if we criticised a ruthless dictator for not being a good father or a prompt payer of debts? Such weaknesses, of course, may not be as significant as the politicisation of the working class, but highlighting both seems to be mere nitpicking. Herman, in almost deifying peasants and miners in glowing icons, showed there was more to his subjects than any propensity for conflict. I recall one of my grandfather-miners telling me that they would never want any of their sons to work underground. So how is one to have a vocation for a job you do because you can’t be bothered to find a less arduous alternative? Herman showed miners putting up with their lot not with any grudging acceptance but with a nobility the miners themselves might not have conceded. That was an act of commission more worthy than anything that, as an artist, he failed to do. But it could never be the whole truth. Berger, too, was full of insights that never worked for anyone else. He claimed that knowing Van Gogh painted his final canvas – the crows in a wheatfield – just before the Dutchman committed suicide made the spectator apprehend it in a totally different way. It never worked for me.