Even after the final page of On the Beach, it may take us a while to grasp the fact that all the characters in the book have committed suicide, the ultimate act of self-destruction. Before the radiation even comes down to kill them, many of the characters are actively seeking out other ways to kill themselves. Moira drinks herself to oblivion, as does Douglas Froude, against his doctor's orders. John tries his best to finish himself off racing in his Ferrari.
Some characters, however, do their best to preserve life, but often do so in a delusional mindset. Mary reacts hysterically to Peter's instructions on euthanizing Jennifer because it is against all instinct for a mother to kill her own child. A mother's role is to create and preserve the next generation, not destroy it. Shute wants to prove that nuclear war is humanity's ultimate act of self-destruction. There is no winner in a nuclear war; even the last survivors get only the prospect of a dignified, self-administered death by pills as their prize. The message is especially meant for those in nations—such as Australia—who like to believe themselves neutral or remote, and therefore untouchable by war.
The characters in the novel have complex relationships with technology: they all know that their lives will shortly end because technological advances have made it possible to eliminate all life with one war, but at the same time, they themselves are unable to abandon their attachment to machines. The qualifying heats for the Australian Grand Prix, for instance, illustrates the dangerous relationship between humans and machines. Although technological gadgets are bringing the world to the end, humans are still in love with these gadgets. At the racetrack, people are more concerned about proving the efficiency of their machines than the safety of the drivers or spectators. Like those who created and used the atomic bomb, the racecar drivers are ready and willing to use technology, but are unwilling to take responsibility for its potential dangers.
Many of the individual characters in the novel show a love for machines. John, for instance, loves his Ferrari. Mary demands an electric lawn mower even though she will die in a few days. Even when Lieutenant Sunderstrom is surrounded by death and destruction in his coastal expedition near Seattle, he still takes time to admire the transmitter sending the radio signal, and he even goes as far as to look for the name of the machine's manufacturer. Sunderstrom cannot bear the prospect of the machine wearing out and breaking, so he turns it off, giving it a more humane death than that experienced by most of the war victims. Efficient, anonymous machines have led to the destruction of humanity, but Sunderstrom, like many other characters in the novel, is still in awe of these scientific creations. Yeoman Swain is another who cannot resist the charm of well-oiled machines. Even though he has just found all his loved ones dead, he is still happy because he has a car and a motorboat. People care so much about technology that now many of them choose machines are their final companions: both Moira and John take their pills in cars. Although this relationship with technology is ironic, Shute does not mock the human love for machines; he merely explores the fact that this love exists.
Moira highlights the dangers of knowledge when she flippantly asks if the Australian government will leave a record of how to make a cobalt bomb. Her remark is all the more powerful because she says it jokingly. While science is sometimes good for human society, technology has also led to its ruin. Radiation is the only lasting legacy of human scientific knowledge, making the link between knowledge and destruction clear.
While scientists should be horrified about the war they helped create, they continue to objectively conduct experiments and search for knowledge. John declares he will enjoy discovering the effects of radiation poisoning, not considering the moral and ethical implications of doing frivolous while so many lives are being lost. It is this scientific objectivity and detachment that made it possible for researchers to create the bombs in the first place. Moira respond sarcastically to John's shocking comments, but John is never fully criticized for his viewpoint. Shute writes like the objective scientist that he was in real life: he observes human behavior, but does not criticize it, leaving readers to draw their own moral and ethical conclusions.
Knowledge is also key to the salvation of the human race. If people had been educated about the dangers of nuclear war, then the catastrophe might never have happened. Before they die, Peter mentions that newspapers could have prevented the war, if the articles they printed actually educated people about how to achieve peace in the world. Education is the key. Like Peter, Shute realizes that newspapers are filled with sensationalist headlines that distract people from the real issues. Because the newspapers are not teaching about the dangers of nuclear war and how to stop it from ever happening, Shute writes On the Beach to serve the purpose. Shute's message is clear about the need to understand that the inevitable will come about if we do not learn how to stop it.
The characters in On the Beach find salvation in work rather than religion. As in many of Shute's novels, the characters are always at work, and in this case, working until the last day of humanity. At first, it seems shocking that Peter would leave his wife and daughter to work when radiation sickness will soon end their lives. But Peter has not yet accepted the fact he will die: he is still planning for his future career, and he knows his wife has the same outlook. Furthermore, he really loves his work. Like many of the characters in this book, Peter would like to spend his last days working. Work is both a salvation and a distraction from thinking about the hopeless times in which they live. Because she does not have work to keep her busy, Moira spends her day drinking. When Dwight suggests to her that the time left might be a "period of grace," he is foreshadowing Moira's transformation into a sober and gentle woman who finds dignity in work during the last months of her life. The novel also shows other people working and taking pride in their work until the very end. During his last trip to Melbourne, Peter takes a ride on a tram driven by a man who says he will continue to drive it until he dies.
The extreme events in the novel shift the characters' definitions of sanity, as nearly all the characters show a resistance to believing and accepting the situation. Dwight, for instance, though a practical man, still believes his family is alive and waiting for him in Connecticut. Delusion has become a practical means to cope with the enormous tragedy of the situation. Throughout the novel, characters continue going about their daily routines, doing their best to let ordinary activities fill their time and thoughts. In these surreal times, however, the more fervently people pursue these mundane activities, the more insane they appear. Peter and Mary's obsession with planning their garden years down the road, for instance, appears ridiculous. John, with his racing, and Douglas, with his vintage wine, are the only two characters who seem to take advantage of these last few days to live out their dreams and break with convention. Perhaps this is because, out of all the characters, these two men are have among the most realistic views of the situation they are in.
On the Beach illustrates the danger of choosing obedience over morality and common sense. Shute implies that people do their jobs without thinking deeply about why they are doing them. Many who are in the government are trained to follow orders—not question them—and that is exactly what they do. For example, Peter fought in the war for a little while even though he did not know why he was fighting. Mindless obedience in the military, especially among its leadership, appears to be one of the primary reasons the war got out of control. Dwight admits he too would have behaved like the rest of the junior officers who were left in control, using every last bomb—he was trained to be obedient, not diplomatic and critically thinking. He would have defended his national honor without thinking of the moral consequences of his actions. Indeed, even in his final day, Dwight refuses to break the Navy rules. His need for obedience and order in his life is greater than his sense of obligation to comfort from Moira in his dying moments, so he prevents her from accompanying him onboard for the submarine's final voyage.
Like Dwight, Allan Sykes, the director of Fishing and Gaming, has a hard time breaking the rules he has obeyed for so long. Even though the circumstances are extreme, he has difficulty bringing himself to open the fishing season early. Because he is a government official, his attitude and behavior can be compared to those statesmen who participated in the nuclear war. These leaders had the choice between obedience and moral bravery and common sense; Shute implies that people will often choose obedience.
In Chapter Eight, Mary hears news on the radio that radiation sickness has reached Sydney, but she ignores the broadcast and pays more attention to the narcissus flower blooming in her garden. The narcissus flower gets its name from Narcissus, a figure from Greek mythology who he created his own doom when he fell in love with his own reflection. Like Narcissus, Mary is self-absorbed, wrapped up in her safe, secure life at home. Mary ignores everything that goes on beyond her home and garden. Shute implies that her lack of concern for the news—strikes, war, wage demands—is symptomatic of a broader lack of awareness in society. By showing Mary's blasé attitude to the news, Shute is warning us that not thinking we are insulated from world events is foolish, and perhaps ultimately dangerous.
"WATER" and "CONTACT" are the only two decipherable words picked up from the mysterious radio signal coming from Seattle. Shute might have chosen those two words because they relate to the book's epigraph, a quotation from T.S. Eliot's poem "The Hollow Men." The poem talks about the last of the world's survivors gathering on the beach of a river. The beach—a place where water makes contact with the land—is the last place where the survivors make contact with each other. According to the poem, the world ends, "not with a bang, but a whimper." The radio signals coming from Seattle, which inspire so much hope in the early part of On the Beach turn out to be merely the last, meaningless whimpers from the dying human race.