Throughout the novel, the native inhabitants of the planet Rohanda (later renamed Shikasta) are developing and growing in their intelligence. However, as soon as they reach a certain level, extraterrestrial forces come in and begin to impose on them. Whether it is for good or for evil, it is revealed that the Rohandans' actions and development come predominately from the influence of these all-powerful alien races who manipulate the will of the people. This is reminiscent of themes in Abrahamic religions, with the will of God being juxtaposed against the machinations of the devil.

In this novel, the world is revealed to be a hypothetical Earth that develops from prehistory and a practical utopia to a modern world on the brink of (and eventually reeling from) World War III. What is interesting is this idea of progress in the novel. The beings develop and become much more technologically advanced, but in the process, they become selfish and evil. This is Lessing's critique of humanity: as we have "progressed," we have actually seen a regression morally and ethically, to the major detriment of our species.

The book's ideas are taken from certain Islamic beliefs, specifically Sufism, which is a mystical form of belief. Lessing represents the spirits and demons of Sufism as different alien groups, separated into three forms: the good (Canopeans), the benevolent but neutral (Sirians), and the evil (Shammat). The battle between good and evil takes place through their intervention in the planet's life and development. This serves as a symbolic portrayal of the nature of angels and demons intervening in Earthly affairs.