From The Paris Review:
In 1963, a sixteen-year-old San Diego high school student named Bruce McAllister sent a four-question mimeographed survey to 150 well-known authors of literary, commercial, and science fiction. Did they consciously plant symbols in their work? he asked. Who noticed symbols appearing from their subconscious, and who saw them arrive in their text, unbidden, created in the minds of their readers? When this happened, did the authors mind?
…The answers to the questionnaire were as varied as the writers themselves. Did Isaac Asimov plant symbolism in his work? “Consciously? Heavens, no! Unconsciously? How can one avoid it?” Iris Murdoch sagely advises that “there is much more symbolism in ordinary life than some critics seem to realize.” Ayn Rand wins the prize for concision; addressing McAllister’s example of symbolism in The Scarlet Letter, she wrote, “This is not a definition, it is not true—and, therefore, your questions do not make sense.” Kerouac is a close second; he writes, “Symbolism is alright in ‘Fiction’ but I tell true life stories simply about what happened to people I know.” The apologies Bruce received from secretaries—including those of John Steinbeck, Muriel Spark, and Ian Fleming—explaining that they were traveling and unable to respond were longer than that.
More here.