Shikasta draws on the Old Testament and is influenced by spiritual and mystical themes in Sufism, an Islamic belief system in which Lessing had taken an interest in the mid-1960s.

Some were impressed by the scope and vision of the book, with one reviewer calling it "an audacious and disturbing work from one of the world's great living writers".

The story of Shikasta is retold in the third book of the Canopus series, The Sirian Experiments (1980), this time from the point of view of Sirius.

When the Natives are ready, Canopus imposes a "Lock" on Rohanda that links it via "astral currents"[2] to the harmony and strength of the Canopean Empire.

Deprived of Canopus's resources and a steady stream of a substance called SOWF (substance-of-we-feeling), the Natives develop a "Degenerative Disease" that puts the goals of the individual ahead of those of the community.

Johor then sends those he has successfully "converted" to spread the word among other Natives, and soon isolated communities begin to return to the pre-Shikastan days.

On the eve of World War III, Sherban and other emissaries relocate a small number of promising Shikastans to remote locations to escape the coming nuclear holocaust.

[7] In the early 1970s Lessing began writing "inner space" fiction, which included the novels Briefing for a Descent into Hell (1971) and Memoirs of a Survivor (1974).

Robert Alter of The New York Times suggested that this kind of writing belongs to a genre literary critic Northrop Frye called the "anatomy", which is "a combination of fantasy and morality".

"[17] Lessing said in 1983 that she would like to write stories about red and white dwarfs, space rockets powered by anti-gravity, and charmed and coloured quarks, "[b]ut we can't all be physicists".

[8] She was awarded the 2007 Nobel Prize in Literature, and was described by the Swedish Academy as "that epicist of the female experience, who with scepticism, fire and visionary power has subjected a divided civilisation to scrutiny".

While she was still a child in Southern Rhodesia (now Zimbabwe) he often used to gaze up at the night sky and say, "Makes you think – there are so many worlds up there, wouldn't really matter if we did blow ourselves up – plenty more where we came from.

[26] It is the story of the planet Shikasta from the perspective of Canopus and is presented as a case study for "first-year students of Canopean Colonial Rule".

[1] He said that the book's cohesiveness is its variety, and noted how Lessing interspaces her "grand designs" and "configurations of enormous powers" with "passages of aching poignancy".

[1] He found Lessing's bleak vision of Earth's history in which she suggests that humans "could not ... help making the messes they have, that their blunders were all ordained by a small tic in the cosmos", a little "unsatisfying", but added that even if you do not subscribe to her theories, the book can still be enjoyable, "even furiously engaging on every page".

[3] Vidal also felt that Zone 6, Lessing's alternate plane for the dead,[a] is not as convincing as The Dry Lands in Ursula K. Le Guin’s Earthsea trilogy.

He compared the Canopeans and Shammat to Milton's God and Satan in Paradise Lost, but said that while Lucifer's "overthrow ... of his writerly creator is an awesome thing", in Shikasta Lessing's human race with no free will is too passive and of no interest.

[3] New York Times reviewer George Stade said that Shikasta "forces us to think about ... what we are, how we got that way and where we are going", but complained that the book is filled with "false hopes", and that the fate of humankind relies on "theosophical emanations, cosmic influences, occult powers, spiritual visitations and stellar vibrations".

M. G. Lord called Shikasta an "epic" and suspected that it may have influenced the Nobel committee when they referred to Lessing as an "epicist of the female experience".

[28] James Schellenberg writing in Challenging Destiny, a Canadian science fiction and fantasy magazine, was impressed by Shikasta's "grand sense of perspective" and the context of humanity set in a "vaster scale of civilization and right-thinking".

[36] The online magazine Journey to the Sea found Lessing's inclusion of stories from the Hebrew Bible "entertaining and intriguing", and said she challenges the logical thinker's rejection of these sacred texts, suggesting that it is "imaginatively possible" that they could be true.