(credit: Karen Gordon, Writer Pictures) 

One of my great-great-grandfathers was a founder of the American-Jewish Lehman banking dynasty, one of my grandfathers was master of an Oxford college, my father was a Tory MP, I went to Eton.

If you come from that kind of background and identify yourself as on the Left, as I do, some shadow of bad faith unavoidably falls across your political journey. After all the Left itself has always placed great stress on "material interests" and "lived experience" as the basis for belief and political action.

If those two factors are removed from the equation what are you left with? Guilt, idealism, book learning or the quirks of adolescent psychology? 

Many years ago I read Hugh Thomas's biography of John Strachey, a minister in the Attlee government, which claimed he became a Communist in the 1930s because he didn't get into the Eton cricket first XI. I realised with some sense of embarrassment that I, too, had become a late adolescent Marxist for similar reasons.

It was not the only reason: the confusion of going to such a self-consciously ruling-class school at a time when it seemed to have lost its legitimacy and wanting to attract the attention of a rather absent father (though I was not aware of that psychological cliché at the time), were probably partial explanations too.

Coincidentally, it was reading John Strachey's Contemporary Capitalism and then even more revisionist works like Tony Crosland's Future of Socialism that led me to the more solid foundations of social democracy after my brief flirtation with the comforting certainties of Marxism.