Alan Taylor in his recently published memoir of Muriel Spark (Appointment in Arezzo) considers what writers most influenced Spark’s works. This was published in connection with Spark’s centenary next year and is included in what is apparently an excerpt from his book in the Glasgow Herald (now called HeraldScotland):
Critics have suggested that in the beginning she was influenced by the likes of Graham Greene and Evelyn Waugh, sharing their adherence to Catholicism and their interest in metaphysics. Of the two, Waugh, with his deft comedic touch, seems to me the better fit. He loved Memento Mori and rarely failed to mention it in glowing terms whenever Muriel sent him her latest novel. But in truth it is hard to find other novelists, stylistically and tonally, not to mention their world view, whose books sit comfortably alongside Muriel’s. She was, as her companion Penelope Jardine has said, simply “sui generis”.
Momento Mori (1959) is not one of Spark’s books that Waugh reviewed, but he must have mentioned it in letters to her. The only one of her books mentioned in his collected Letters addressed to her is The Bachelors. In an October 1960 letter he thanked her for a copy of that book and described it as “the cleverest & most elegant of all your clever & elegant books.” He also offered her a blurb for the publisher if one was wanted: “I am dazzled by The Bachelors” and agreed to the use of “anything else in the foregoing homage” (Letters, p. 551). The publishers apparently took him up on his offer as his description of the book as quoted from the text of the letter still appears in the Amazon.com listing.
