Why does Perrie Aronnax seem obsessed with the nationality of everyone he meets?
In part, Aronnax is obsessed with other people's nationalities because of the pervading sense of European superiority at the time. For example, he says of Cunard, a British shipping line, "No ocean-going company has been run with greater skill; no business crowned with greater success." In an age of colonialism and sea power, he believes in the right of Europeans, including Frenchmen like himself, to exercise control over the seas. Against this backdrop, even research into the mysterious monster observed on the sea acquires political dimensions. He says, "after research had been carried out in Great Britain, France, Russia, Prussia, Spain, Italy, America, and even in Turkey, the hypothesis of a submarine Monitor was rejected once and for all." He is embroiled in the scientific controversy not only as individual but also as a representative of France.
Aronnax is also obsessed with nationality because he cannot determine where Captain Nemo is from. Nemo's origins, though he speaks French fluently, remain a mystery throughout the entire tale. Aronnax tries to understand Nemo by determining where he is from, but Nemo defies any categorization. For Aronnax, who believes that each nation's people have their own character, this is deeply disturbing. The idea that a person is not from a particular country does not fit into Aronnax's colonialist and Eurocentric view of the world.
Jules Verne’s classic Twenty Thousand Leagues Under the Sea is set in the late 19th century, during the time of the rise of nations as political entities. Professor Aronnax seems to be a true patriot of his own nation, France, and he seems determined to rank others with respect to how their nationalities compare to his own. Also, Aronnax is a scientist through and through, and he attempts to classify and understand everything he encounters and everyone he meets. The recognition of nationality, especially given the time period, is the most prominent way for him to classify and understand other people.
Stepping outside of Aronnax’s character, the reader should also consider that Verne may have wanted his readers to understand something that Aronnax seems incapable of accepting—that Captain Nemo cannot be classified as belonging to any nation because he is sovereign to himself. Thus, when Aronnax is perplexed by not being able to place Nemo’s nation of origin, we may interpret this as Verne’s way of showing us that Nemo is a man apart, an enigma that both terrifies and fascinates Aronnax because the object of his study cannot be easily classified into the nationalistic paradigm of his age.