In much of his fiction, Arthur C. Clarke supports the idea that knowledge, particularly knowledge of technology, equals power—and not just physical power, but psychological power as well. One of Clarke's three "Laws" is the idea that "any sufficiently advanced technology is indistinguishable from magic." In Childhood's End, the Overlords use their technology to achieve both these ends. The vast technological superiority of the Overlords apparently knows no bounds. They can spy on anything that happens on the surface; they can project artificial copies of their ships so convincing that they even make a sound as they enter the atmosphere; they can inflict pain without causing a wound; they can block out the sun over specific geographic areas; and they can alter a planet's gravity, to list just a few of their powers. They also have the Stardrive, which lets them fly their ships at the speed of light.
On Earth, the Overlords use this technological power to exert benevolent but totalitarian rule. They create a utopia on Earth through what Karellen calls a "correct use of power." "Correct" in his idea means "efficient"; rather than destroying a rebellious country, Karellen destroys its power by driving its leaders mad, or with a simple—but harmless—show of power, such as blotting out the sun. But Karellen's use of the term "correct" does not include a value judgment on whether the action being taken is the "right" one. Stormgren's objection to this claim is that it sounds like "might makes right," to which Karellen replies with his argument about efficient and inefficient uses of power. Karellen does not address Stormgren's true objection: that regardless of how efficient the Overlords' use of their "might" is, they are still determining what is "right." As the existence of groups such as the Freedom League reveals, not everyone on Earth believes that the Overlords' efforts to create a utopia are what is right for humanity.
Of course, another aspect of this theme is the limitations of technology. In Childhood's End, knowledge and technology is a dead-end. The Overlords have mastered technology, but they are unable to make the transcendental leap to the next stage, that of the Overmind. This idea is unique among most of Clarke's works, which generally espouse the idea that knowledge and technology represents the future of mankind. In order for it to surpass technology, Clarke is forced to make the Overmind a vague, mystical, and perhaps even mythological entity.
While the main concepts of Childhood's End revolve around the irony of the Overlords as benevolent masters that look like "devils" and the division between technological and evolutionary achievement, the book also deals heavily with the possible problems of a utopian society. Before we are even aware that the Overlords have started making beneficial changes to the Earth's economic and political systems, we are introduced to the Freedom League, composed of humans who object to the Overlords' meddling in human affairs. The Freedom League does not object to the policies of the Overlords, it objects to the Overlords' very presence. To a degree, Wainwright is correct; the Overlords remove all of humanity's dreams, goals, aspirations, and struggles. In eliminating conflict, the Overlords put humans in a position where they have only once choice: begin educating themselves and exploring, or decline into stagnation. Since the Overlords refuse to allow mankind to enter space, there is no choice but stagnation. For a time, people attempt to fight off boredom through education and entertainment. Eventually, and perhaps inevitably, people like Jan Rodricks became restless. As the narrator notes, "no utopia can ever give satisfaction to everyone." As a utopia progresses, the more dissatisfied or degraded its people will become. Boredom will give way to violence and moral depravity. This often happens whenever things are going well for a large number of people and often represents the self-destructive downfall of many a government.
Moral depravity is not the only problem that utopias eventually face. There is also the problem of artistic stagnation, which is addressed in the novel by the creation of New Athens. Without discontentment, without strife or struggle, artistry will necessarily suffer. As more people have more leisure time, there is more art, and thus humanity begins to drown in so much art that there is no clear way of determining "good" from "bad." The New Athens colony was doomed from the start; it was merely an attempt to create a utopia within a utopia.
But aside from addressing the practical—and perhaps rather obvious—problems of utopian society, Childhood's End also presents a rather problematic situation. Evolution works primarily by isolating those more fit to survive; the weak die, leaving the strong and the adaptable. But as the standard of living is raised across the globe, as even the lazy are allowed to live out their lives with the basic necessities, there is none of this weeding out process going on. Therefore, when the children begin their strange transformation into the Overmind, the process cannot be considered "evolution." In order for it to be considered so, one must alter the definition of "adversity": in the face of utopian stagnation, the children must mutate into the Overmind in order to fight off their complete degradation into animals.
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.
Deception is rampant in Childhood's End. Deception is a trick of knowledge; the less you are deceived, and the better you are at deceiving others, the more powerful you are. The best deceivers are, of course, the Overlords, who deceive mankind on dozens of different points. Karellen deceives Stormgren by hiding behind a piece of one-way glass and calling it a "viewscreen" and by planting a tracking device on Stormgren. Stormgren, for his part, sneaks a scanner into Karellen's room and then tries to use a flashlight to see through the glass. Karellen has the greater power, of course, because he is aware of both of Stormgren's deceptions, just as he is (almost certainly) aware of Jan Rodricks's plan to sneak aboard an Overlord vessel many years later.
The Overlords deceive humanity from the start, never revealing their intentions until the children of the last generation begin to mutate into the Overmind. The Overlords visit New Athens under the pretence of inspecting the island, when actually they just want to check up on Jeffrey. Stormgren's kidnappers try their hardest to trick the Overlords. Jan does his best to deceive the Overlords when he sneaks on to their ship. Deception is a major tool of intellectual control, and though the Overlords are the masters of it, it is the primary weapon of both humans and Overlords throughout the novel.
As frequently discussed elsewhere in the summary analyses, Childhood's End often seems like an allegorical tale, a morality play set on a science fiction stage. The play features the arrival of the Antichrist, or Satan (the Overlords), the end of humanity (as it dies out after the Overlords' announcement of the coming of the Overmind), and an Armageddon and assumption of the "faithful" into "Heaven" (as the children of the last generation join the Overmind, destroying the Earth in the process). Considering its unique and transcendental nature, when compared to the rest of Clarke's works, it seems entirely reasonable to look at Childhood's End as a thinly-veiled fable with some significant social commentary (particularly about the nature of utopias), rather than a work of serious science fiction.
Part of the description of the Overmind is that it is a kind of "collective conscious," a being of thought and energy composed of the minds of millions or billions (even trillions?) of other beings, all working as a single entity. As a race, all humans—even those thousands of years before the children of the last generation—have had some latent abilities of this sort. This is what provides the explanation for why the Overlords look so similar to a Christian image of the Devil: humans, as a collective, had a premonition of their ultimate end, and they feared that end. Therefore, they made the participants of that end, the demons, into an object of fear and evil. This collective consciousness also appears in specific people such as Jean and Jan, who often have slight premonitions before major events occur.
As mentioned above, the Overlords can be seen as ironic symbols of the Devil. In an unexpected, but equally effective way, the Overlords bring about the end of humanity just as the Devil was predicted he would. Whereas the Devil, or the Antichrist, would have brought about much death and destruction before the final end, the Overlords bring about peace and prosperity, albeit for less than a century. In the end, humanity does degrade into violence and death, just as predicted in Revelations; and the shepherds of this end are the Overlords. Whether they are "evil" or not is a matter of perspective; they do the bidding of the Overmind and play a part in the end of humanity and the destruction of Earth.
New Athens is symbolic of the inevitable decay of a utopian society and the uselessness of peacefully attempting to combat those problems. For all its hopes of artistic achievement, the New Athens colony is ultimately impotent. Without struggle, without anger, righteous indignation, rage, or hate, artists have no fuel with which to produce great works. New Athens, in its false attempts to create minor inconveniences in life (such as using kitchens and bicycles), tries to create a utopia within a utopia. New Athens is a symbol of the broader utopia of Earth around it. Both are doomed to failure through degradation.
If the Overlords represent the Devil, then the Overmind is the closest thing there is to God. Certainly, the way in which the children of the last generation are incorporated into the Overmind is reminiscent of Christian descriptions of the Rapture, when the souls of the faithful are called into the Divine Presence, there to remain for eternity as part of the Holy Trinity. But, in theory, the Overmind is a thing of science; it should be capable of being studied, understood, and perhaps even destroyed. By placing the Overmind in a science fiction novel, there are certain constraints on how far a symbolic or allegorical comparison can be taken. Ultimately, the reader must accept the idea that, as transcendental as it seems to be, the Overmind is just another alien.