Blake’s view was that [quoting Northrop Fryle] “history as linear time is the great apocrypha or mystery which has to be rejected” since “the whole of human life is seen and understood as a single mental form” (p. 340) The linear view of history began with Petrarch and Leonardo da Vinci and ended with Gibbon and Hume. So obsessive a metaphor as that of linear perspective is important enough to deserve some explanation, especially since we are now deep in the process of extricating ourselves from it.