Là-Bas by Joris-Karl Huysmans

From this scene he had learned an alarming lesson: that the flesh domineers the soul and refuses to admit any schism. The flesh decisively does not intend that one shall get along without it and indulge in out-of-the-world pleasures which it can partake only on condition that it keep quiet. For the first time, reviewing these turpitudes, he really understood the meaning of that now obsolete word chastity, and he savoured it in all its pristine freshness. Just as a man who has drunk too deeply the night before thinks, the morning after, of drinking nothing but mineral water in future, so he dreamed, today, of pure affection far from a bed.

He was still ruminating these thoughts when Des Hermies entered.