In Leaves of Grass, Walt Whitman writes,
Passage to India!
Lo, soul! seest thou not God's purpose from the first?
The earth to be spann'd, connected by net-work,
The people to become brothers and sisters,
The races, neighbors, to marry and be given in marriage,
The oceans to be cross'd, the distant brought near,
The lands to be welded together.
It was from this poem that E. M. Forster took the title of his novel, and the relevance to his subject matter is immediately clear, though Forster is much more pessimistic than Whitman in his ideas about the possibility of human brotherhood. Having made "only connect" the central theme of Howards End, he seems in A Passage to India to be questioning the very possibility of connection between people across cultures, and even within them.
Quite apart from the themes of connection raised by Whitman, the notion of "a passage" to India is appropriate, because it emphasizes that the British characters, like Forster himself, are passengers, little more than tourists, however long they have lived in the country. Adela and Mrs. Moore are literally passengers, and their passage to India is described, but the "Turtons and Burtons" are no more genuinely at home in the vast country.
In his essay on Rudyard Kipling, George Orwell makes the point that Kipling was only able to survive in the colonial atmosphere because he was barely civilized himself. There is no point in wishing, Orwell says, that we had an intimate portrait of India written by a sensitive liberal like E. M. Forster, for Forster could not have endured the stupidity and bigotry of the people Kipling knew (who were, in fact, only just endurable for Kipling). Forster traveled extensively in India but never spent much time in one place, leaving us with a book about British passengers in India by one of their own.