Lessing's fiction is commonly divided into three distinct phases: the Communist theme (1944–1956), when she was writing radically on social issues (to which she returned in The Good Terrorist (1985)), the psychological theme (1956–1969), and after that the Sufi theme, which was explored in a science fiction setting in the Canopus series.
Lessing's switch to science fiction was not popular with many critics. For example, in the New York Times in 1982 John Leonard wrote in reference to The Making of the Representative for Planet 8 that "One of the many sins for which the 20th century will be held accountable is that it has discouraged Mrs. Lessing.... She now propagandizes on behalf of our insignificance in the cosmic razzmatazz." To which Lessing replied: "What they didn't realize was that in science fiction is some of the best social fiction of our time. I also admire the classic sort of science fiction, like Blood Music, by Greg Bear. He's a great writer." Unlike some authors primarily known for their mainstream work, she has never hesitated to admit that she writes science fiction. She was Writer Guest of Honour at the 1987 World Science Fiction Convention (Worldcon), and made a well-received speech in which she described her science-fictional Memoirs of a Survivor as "an attempt at an autobiography."