It was not right of Coleridge in fact it was wrong
(But often we all do wrong)
As the truth is I think he was already stuck
With Kubla Khan.He was weeping and wailing: I am finished, finished,
I shall never write another word of it,
When along comes the Person from Porlock
And takes the blame for it.

Coleridge’s Person from Porlock had a good few outings in the mid-twentieth-century.
For instance, R. S. Thomas published ‘A Person from Porlock’ in 1955:
There came a knocking at the front door,
The eternal, nameless caller at the door;
The sound pierced the still hall,
But not the stillness about his brain.
It came again. He arose, pacing the floor
Strewn with books, his mind big with the poem
Soon to be born, his nerves tense to endure
The long torture of delayed birth…
Stevie Smith followed, in 1962, with ‘Thoughts About the Person from Porlock‘, perhaps the most famous literary response to Coleridge’s interrupter. Her Person from Porlock is half-death, half-ministering angel. His arrival, Smith’s speaker imagines, will both allow her to stop writing, and inscribe what she has written with a sublime, untouchable finality:
I am hungry to be interrupted
For ever and ever amen
Oh Person from Porlock come quickly
And bring my thoughts to an end.
Hank …you remember that letter I got this morning?
Sarah About artists’ careers being interrupted by the war?
Hank Interrupted! The understatement of 1946. Have we got a Coleridge in the house?
Sarah Coleridge? I’ll look.
Hank When one’s interrupted one can’t pick it up again. It’s happened to me all my life. My mother’s lover with the bar of marzipan, and then the war itself –
Sarah Here you are; service! Collected Poems of Coleridge.
Hank Now wait till I find it; this is all about me, darling. Here you are: ‘Kubla Khan: or, A Vision in a Dream’.
Hank is of course the ‘Coleridge in the house’, interrupted by a series of Persons from Porlock – the war, the lure of an advertising career, alcohol – before he could reach his full artistic potential. As he lies half-conscious in the cave, a final Person from Porlock – death – comes and speaks to him.
Person …The ironic thing is: this will sell your pictures…
Hank …But tell me – before I drop off – why is this going to sell them?
Person Because they will say he met a noble – well, a noble person from Porlock.
Though Coleridge’s Person from Porlock disrupted ‘Kubla Khan’, prevented it from being fully written, Hank’s Person from Porlock – a final, irrefutable interruption – is in fact the interruption which establishes, and immortalises, his artistic career. Death casts the light of romance over his work, positions it within a tragic narrative. Without the Person from Porlock, his paintings would not have sold.
As MacNeice’s Hank points out, the second world war was an interruption. Perhaps, after that, postwar life felt precarious: open and poised for a further interruption. In Smith’s 1949 novel The Holiday, Celia describes the postwar period as an interminable limbo: ‘When will the postwar end, shall we win the postwar[?]’ Interruptions are dreaded but hoped-for: the events which will give both personal and political history comprehensible shape and value.
So both Smith’s and Thomas’s Persons are potentially godlike figures – Thomas’s is ‘eternal, nameless’, while Smith invokes hers with a chant of ‘For ever and ever amen’. These Persons bring salvation. MacNeice’s Person is more circumspect: he brings a touch of irony. Whether something is seen as worthy or worthless depends only on the circumstances which bring it to a halt.