It is hard work to control the workings of inclination and turn the bent of nature; but that it may be done, I know from experience.
– Charlotte Bronte
Jane Eyre, Chapter 31. St. John tells Jane how hard it is to overcome natural inclinations, but he assures her that it can be done. Shortly after this we learn what St. John means. He is actually in love with Roamond Oliver, but constantly uses religion to temper his actions and supress his desires.