Richard Holmes in the New York Review of Books:
There are many William Blakes, but mine arrived with the tigers in the 1960s. The first line I ever read by Blake was not in a book, but laid out in thick white paint (or should I say illuminated) along a brick wall in Silver Street, Cambridge, England, in 1968. It was not poetry, but prose: “The tigers of wrath are wiser than the horses of instruction.” It sent a strange shiver down my spine, as it did for thousands of other university students in England and America that year.
It turns out that, according to The New York Times of December 28, 1968, exactly the same line from Blake’s “Proverbs of Hell” appeared on big posters at the conference of the Modern Language Association in New York. According to the Times it signified that “Radical Agitation Among Scholars Grows,” and it led to several arrests.
This of course was the time of radical disturbances on university campuses across Europe, as well as Vietnam War and civil rights protests in America. Very quickly we all seemed to be reading Blake’s preface to Milton.
More here.