Eric Hobsbawm, grandfather of Marxist academics, writes, "Socialism has failed. Now Capitalism is bankrupt. So what comes next?"
His answer, in not as many words, is green economics, by which we mean a mixed economy, public and private, with a market guided by taxes and regulation towards equity and sustainability.
It is going to be a bigger shift than Mr Brown imagines.
(Cue Bob Dylan singing
"There's something going on around here and you don't know what it is, do you, Mr Brown?"
Welcome aboard, Eric.