JERUSALEM. Lament, tragedy, invocation, cry? William Blake and the play that forgets his name

Jerusalem by Jez Butterworth, starring Mark Rylance, is brilliant. But what can be made of its violence and passion, humour and hedonism, tragedy and emptiness?

Returning to the source of the famous words after which the play is named provides a clue. William Blake is right to invoke. He has something to say...