“You are original,” said he, “and not timid. There is something brave in your spirit, as well as penetrating in your eye; but allow me to assure you that you partially misinterpret my emotions…When I colour and when I shake before Miss Oliver, I do not pity myself. I scorn the weakness. I know it is ignoble – a mere fever of the flesh; not, I declare, a convulsion of the soul…Know me to be what I am – a cold, hard man.”
– Charlotte Bronte
Jane Eyre, Chapter 32. There you have it! St. John admits to Jane to being emotionally cold and hard. When it comes to duty to serving God versus passion for a woman, duty comes first. The affairs of the soul take precedence to the desires of the flesh, which St. John dismisses as weakness. So for the unfortunate Miss Oliver there is no place in St. John’s scheme of things. However, he appears to be taking an interest in Jane, admiring her for her brave spirit.