William Blake, London & fourfold vision – reflections from Waterloo Bridge

William Blake famously remarked in a letter to Thomas Butts:
“Now I a fourfold vision see,
And a fourfold vision is given to me;
‘Tis fourfold in my supreme delight
And threefold in soft Beulah’s night
And twofold Always. May God us keep
From Single vision & Newton’s sleep!”
But what does it mean to see fourfold, threefold, twofold or with single vision – which is to say with the perception of Eden-Eternity, Beulah, Generation or Ulro?
A consideration of the architecture viewed from Waterloo Bridge is illuminating, taking a lead from Kathleen Raine’s talk on Blake’s Fourfold London.
Her original talk is online.