He prizes me as a soldier would a good weapon; and that is all. Unmarried to him, this would never grieve me; but can I let him complete his calculations – coolly put into practice his plans – go through the wedding ceremony? Can I receive from him the bridal ring, endure all the forms of love (which I doubt he would not scrupulously observe) and know that the spirit was quite absent? Can I bear the consciousness that every endearment he bestows is a sacrifice made on principle? No: such a martyrdom would be monstrous. I will never undergo it. As his sister, I might accompany him – not as his wife: I will tell him so.
– Charlotte Bronte
Jane Eyre, Chapter 34. Jane says this to herself after St. John Rivers asks her to marry him and accompany him on his missionary work to India. But Jane knows that he will never love her. St. John “has no more of a husband’s heart for me than that frowning giant of a rock, down which the stream is foaming in yonder gorge.” Jane decides to make clear that if she goes, it will be as his equal and they go as brother and sister, not husband and wife. “I am ready to go to India, if I may go free,” she tells him after the above passage.