The people in Diaspar are machines designed by the creators of the city. Khedron, the jester, often feels resentment that after so many years, the designers can still "make him move like a puppet across their stage" (53). The people are altered physically in that they have no body hair or fingernails, and they lack navels. They are mechanical reproductions now that they have lost the ability to physically reproduce themselves. They are re-created from the same pattern century after century – they are replications of themselves and one another.

Clarke points out the absence of difference in Diaspar. As adults, the people have equal access to every aspect of the city – there are no hierarchies that give some privileges that others are denied. The only exceptions, of course, are the areas to which the computers prohibit them from going. The people no longer rule the technology; rather, the machines are "the real administrators of Diaspar" (55).

The most destructive characteristic, however, is the complete loss of human spirit – the innately human drive responsible for motivation or passion of any form. Clarke uses Lys to highlight the lack of human spirit in Diaspar. Once in Lys, Alvin encounters love for the first time in his life. He recognizes that the people in Diaspar experience love mechanically and incompletely because they do not possess tenderness. In Jeserac’s saga at the end of the novel, Yarlan Zey explains that the creators of Diaspar "redesigned the human spirit, robbing it of ambition and the fiercer passions, so that it would be contented with the world it now possessed," so that it would be contented as a machine (244).

Clarke points out the superiority of Lys over Diaspar, and thereby shows us the importance of the human spirit that the people of Lys possess and utilize. Moreover, he reveals that not only is it better to live in possession of the human spirit, it is in fact, the only way to live. Throughout the novel, he shows Diaspar to be only an image – the buildings are not material, they are atomized. He describes the city as though it is a holographic picture, just as Khedron tells Alvin that the model of Diaspar in City Hall is an "infinitely detailed simulacrum…it does not really exist" (56).