Several of Clarke's novels tackle the big questions of the meaning of human existence. Much like 2001: A Space Odyssey,Childhood's End tries to find a purpose for humanity by putting it against a backdrop of alien intelligence. Clarke has often said that he believes humanity is meant to reach out into space and explore the stars. However, in Childhood's End, most of the characters—particularly the Overlords and Jan Rodricks—agree that "the stars are not for man."
What, then, is the purpose of human existence? According to Karellen, all of human development leads up to the moment when the children of the last generation join the Overmind. The Overmind, then, becomes an end—and a meaning—unto itself. But what are the motives of the Overmind? Karellen and the Overlords only have a theory that that Overmind is trying to increase its "awareness of the universe." Whatever the Overmind's plans, it seems difficult to equate its purposes with that of mankind. In the novel, the purpose of mankind is only to develop to the point at which it can join the collective conscious of the Overmind. As Karellen says when he announces the transformation of the children, "All the hopes and dreams of your race are ended now." To a student of Clarke's fiction, there cannot be a darker or more blasphemous pronouncement. Humanity's scientific and technological progress, its curiosity and efforts at bettering itself, have been halted by a mystical, almost supernatural energy force called the Overmind. Despite Karellen's claims that the Overmind is something "wonderful," it seems like cold comfort to know that your children will live on, without individuality or personality, within a being of pure energy and thought.