'Culture clash' is the most important theme in A Passage to India. What are the other themes in the novel?

This novel also deals with such themes as friendship, public and private life, and ambiguity ("mystery" and "muddle"). Aziz and his friends discuss whether it possible to be friends with an Englishman; Mahmoud Ali argues it is not. This conversation relates to the clash between two cultures, but it ultimately prepares the reader for the relationship between Aziz and various British colonials such as Fielding, Miss Quested, and Mrs. Moore. Within the Indian culture as well you can examine the friendships between Aziz and his fellow Indians, Hamidullah, Mahmoud Ali, and the Nawab Bahadur. The puzzling events in the Marabar Caves contribute to the ambiguity in the novel although this theme is not limited to the central part of the book. See the link below for further explanation of themes.