The above paragraph illustrates the awkwadness that Franklin's many-sided personality produces. His French side shows his levity in serious discussions while his German side is philoophical in nature. He loses all intellect with his Italian side while his English side is uncouth and insular. Franklin, in his narrative, completely rejects Betteredge's hypothesis.
Sergeant Cuff is another character that has a dual nature. Cuff is the famed detective that is hired to solve the mystery of the diamond. He is able to uncover numerous clues at the beginning of the novel and at the end and names Godfrey as the thief before such is discovered. However, he has a fascination for roses and repeatedly debates the Verinder's gardener about the estate's rose garden:
Despite being in the middle of an investigation, Cuff feels sufficiently confident enough in his abilities to pause momentarily and debate the gardener on the subject of roses. A love of detective work and roses does not seem to be compatible but Cuff explains the apparent contradiction:
Cuff is convinced that having opposing interests is a part of human nature.
Even the devout Miss Clack displays a dual nature. She is persistent in passing out tracts, such as "A Word With You On Your Cap-Ribbons," and keeping everyone from the flames of Hell but Betteredge points out that she drank liberally of the wine during the birthday dinner. Also, despite her Christian wisdom, she proves to be a bad judge of character in her assessment of Godfrey, whom she paints as a true Christian devoted to poor women's causes but who turns out to be the villain in the novel. Collins uses Miss Clack to poke fun at organized religion.