Excerpt from Kokoro by Natsume Sōseki.

It was not so much that

the thought of the shame was painful to me; it was rather that, no matter how I loved her, I hated the thought of marrying a woman who secretly longed for another. Many men are perfectly happy to marry the girl they love whether she returns the feelings or not, but in those days I considered such men to be more worldly and cynical than we were, or else more obtuse to the workings of love. I was much too ardent to have any truck with the notion that once you marry you somehow simply settle down. In a word, I had a romantic faith in the nobility of love, while simultaneously practicing a devious form of it.