Describing IPH (a lay Institute of Preparation for the Hereafter) in Canto Three of his poem, John Shade (the poet in VN's novel Pale Fire, 1962) says that IPH borrowed some peripheral debris from mystic visions:
While snubbing gods, including the big G,
Iph borrowed some peripheral debris
From mystic visions; and it offered tips
(The amber spectacles for life's eclipse) -
How not to panic when you're made a ghost: