Twenty Thousand Leagues Under the Sea

A major theme throughout the book is the contrast between liberty and imprisonment. Professor Aronnax, Ned, and Conseil are held hostage on board the Nautilus. Captain Nemo makes the terms of their situation on the Nautilus clear—they must stay on board to keep the existence of the ship a secret.

Although they often enjoy their experiences, particularly Professor Aronnax, they never mistake their luxurious captivity for freedom. When Captain Nemo proclaims that Professor Aronnax, Ned, and Conseil can do whatever they want aboard the ship, Professor Aronnax responds that “this liberty is only what every prisoner has of pacing his prison,” adding that it “cannot suffice” (41). Professor Aronnax, even when he still personally admires Nemo and marvels at his newfound access to undersea nature, insists to Captain Nemo that holding them captive is “cruelty” (41) and laments that their “only course was to submit” (176). Professor Aronnax eventually tells Captain Nemo that their imprisonment echoes “actual slavery” (226), and every slave has a right to gain their freedom.

Ned is the most adamant about escaping. He finds his circumstances “intolerable,” as he is accustomed “to a life of liberty and activity” (180). He tells Professor Aronnax and Conseil he is waiting for a “favourable opportunity” to leave the Nautilus (146)—and makes it clear that he would be happy to die in the attempt. Professor Aronnax and Conseil agree, now willing to risk their lives for their freedom. “Liberty,” insists Ned when he is prepared to face a tumultuous sea to escape, “is worth paying for” (157). 

The novel presents innovation, exploration, and discovery as ways of countering hatred and anger. Professor Aronnax constantly desires to learn and study, and for much of the book finds Captain Nemo an invaluable guide, even referring to him as a “genie of the sea” (165, 241).

Innovation drives the first part of the novel. Captain Nemo impresses Professor Aronnax with the unbelievably high-tech submarine he pilots. He shows off inventions like his electricity-powered navigational system, a diving apparatus that allows them to walk on the bottom of the sea, and other technological novelties. Nemo’s ingenuity is one of the reasons Professor Aronnax is drawn to him, and deems him a man he understands. After a tour of the ship, Professor Aronnax exclaims that it is “a marvelous boat” (55) and that Captain Nemo is “an engineer of a very high order” (51).

The Nautilus is an exploration vessel, traveling to remote regions and depths that no one has ever been before. Their initial voyages are scientifically minded: Professor Aronnax is “dazzled” (60) by the wide range of aquatic life he observes and analyzes, and which are often named and described in detail. Of their first submarine excursion into the forest to hunt, Professor Aronnax states that “Words are impotent to relate such wonders!” (68). Besides zoology and botany, Professor Aronnax gets a taste of anthropology when Captain Nemo takes him pearl diving, and later reveals an underwater cemetery in a coral reef.

The novel is also fascinated with the idea of discovery. For verisimilitude, Verne often alludes to the expeditions of famed French explorers, including Lapérouse and Dumont d’Urville. Their real-life voyages buttress the novel’s invented ones, as when Captain Nemo shows Professor Aronnax the lost civilization of Atlantis, discovers a tunnel between the Black Sea and the Mediterranean, and becomes the first person to land at the South Pole. The novel draws on firsthand accounts of explorers when Professor Aronnax declares he can hardly believe he is “touching with my hand those ruins a thousand generations old,” and “walking on the very spot where the contemporaries of the first man had walked” (168). Although Captain Nemo’s character takes a dark turn, Professor Aronnax hopes his hatred is extinguished by his continued “peaceful exploration of the sea!” (244).

The survival of Professor Aronnax, Ned, and Conseil, both on the Nautilus and during their escape, relies on their deep-seated friendship. Professor Aronnax is always dedicated to the needs of his two companions, even when he is still impressed with Captain Nemo. His dedication grows even stronger as Captain Nemo becomes increasingly obsessed with revenge. Aronnax supports Ned’s desire to escape, and never wavers in his allegiance to Ned and Conseil—who demonstrate that they are willing to sacrifice their own lives to save Professor Aronnax when they give him the last of the oxygen in Antarctica. He refers to them as his “two brave friends” (210) and feels he will never be able to repay Ned and Conseil for “such devotion” (211). They are finally able to escape together, embracing “each other heartily” (243). Their survival would not have been possible without their loyalty to one another.