In A Passage to India, many of the characters arrive on the scene with their own mini-biographies and complete psychological profiles. The narrator goes into extensive detail about what the characters are feeling, what social and cultural forces shape them, and even what half-formed opinions and desires are percolating in their unconscious. Before we can come to our own conclusions as to whether Adela is confused or Aziz is being dishonest, the narrator just comes out and tells us so. This kind of direct characterization has its limitations, even if it is exhaustively informative. For example, it makes the novel's own biases painfully clear. Some of the novel's comments about female and Indian (or "Oriental") characters can be patronizing.
The novel dives right into characters' heads, getting into the muck of their confused thoughts and aspirations as they negotiate life in Chandrapore. Since one of the main themes of the novel is how the "Western" mind, with its emphasis on reason and logic, is affected when it encounters the exotic East (see our discussion of "Contrasting Regions" under "Themes"), the novel is intimately concerned with how the Western characters grapple with the vastness of India, its culture and society. But it also wants to portray the "Oriental" mind as it exists in Indian characters such as Aziz, Godbole, and Hamidullah. It seeks to counter the stereotype that Orientals are passive, amoral, sexually predatory and incapable of rational thought by giving a thoughtful and well-rounded representation of Indians, even though it is not entirely free of its own racial prejudices.
Fielding believes in the benefits of free and rational dialogue, and you could say the novel feels the same way. We're given pages upon pages of dialogue as the primary mode of interaction between the characters. Conversation isn't just a way to get to know another person, but an encounter between different cultures. Even if Aziz isn't entirely accurate in his portrayal of Mughal history, what's more significant is that Adela and Mrs. Moore are exposed to his way of thinking about the world. Speech saves Aziz at the trial, when Adela finally remembers that he did not attack her in the cave when she is forced to talk about her experience. And conversation saves what's left of Aziz and Fielding's friendship by giving them a chance to clear up their misunderstanding.