Henry James

Henry James definitely gets right to the core in this quote:
"My idea is this, that when you only love a little you’re naturally not jealous-or are only jealous also a little, so that it doesn’t matter. But when you love in a deeper and intenser way, then you’re in the very same proportion jealous; your jealousy has intensity and, no doubt, ferocity. When however you love in the most abysmal and unutterable way of all – whey then you’re beyond everything, and nothing can pull you down."
— Henry James (The Golden Bowl)

It makes me want to re-read The Golden Bowl, but no, I am not even going to go there. 4 books is quite enough!