At long last, Armstrong reveals his true intentions for seducing Isobel. Armstrong’s fascination with Isobel’s back blurs the line between passion and scientific curiosity—he admits that her back excites him much in the same way that he “find[s] electricity exciting, or the isolation of oxygen, or the dissection of a human heart.” In other words, Armstrong’s erotic desires and thirst for knowledge are both driven by passion. This challenges views that Roget has previously expressed—that human curiosity can be totally neutral and exist separately of things like human morality, emotions, or passions.