Initial response to the novel was mixed, but it drew responses from newspapers and magazines normally inattentive to science fiction. A Canticle for Leibowitz was reviewed in such notable publications as Time, The New Yorker, The New York Times Book Review, and The Spectator.[16] While The New Yorker was negative – calling Miller a "dull, ashy writer guilty of heavy-weight irony"[20] – The Spectator's was mixed. Also unimpressed, Time said, "Miller proves himself chillingly effective at communicating a kind of post-human lunar landscape of disaster", but dubbed it intellectually lightweight.[21] The New York Times Book Review's Martin Levin, however, hailed the work as an "ingenious fantasy".[22] The Chicago Tribune gave the book unusual exposure outside the genre in a front-page review in the Chicago Tribune Magazine of Books, reviewer Edmund Fuller calling the book "an extraordinary novel".[23] Rating it five stars out of five, Floyd C. Gale of Galaxy Science Fiction said that "It has many passages of remarkable power and deserves the widest possible audience".[24] A decade later, Time re-characterized its opinion of the book, calling it "an extraordinary novel even by literary standards, [which] has flourished by word of mouth for a dozen years".[25] After criticizing unrealistic science fiction, Carl Sagan in 1978 listed A Canticle for Leibowitz as among stories "that are so tautly constructed, so rich in the accommodating details of an unfamiliar society that they sweep me along before I have even a chance to be critical".[26]
A Canticle for Leibowitz was an early example of a genre story becoming a mainstream best-seller after large publishers entered the science-fiction market.[27] In 1961 it was awarded the Hugo Award for Best Novel by The World Science Fiction Convention.[1] In the years since, praise for the work has been consistently high. It is considered a "science-fiction classic ... [and] is arguably the best novel written about nuclear apocalypse, surpassing more popularly known books like On the Beach".[28] The book has also generated a significant body of literary criticism, including numerous literature journal articles, books and college courses.[29] Acknowledging its serialization roots, literary critic David N. Samuelson writes that the novel "may be the one universally acknowledged literary masterpiece to emerge from magazine SF".[30] Fellow critic David Cowart places the novel in the realm of works by Evelyn Waugh, Graham Greene, and Walker Percy, in 1975 stating it "stands for many readers as the best novel ever written in the genre".[31] Percy, a National Book Award recipient, declared the book "a mystery: it's as if everything came together by some felicitous chance, then fell apart into normal negative entropy. I'm as mystified as ever and hold 'Canticle' in even higher esteem".[32] Scholars and critics have explored the many themes encompassed in the novel, frequently focusing on its motifs of religion, recurrence, and church versus state.[33]
