"Jane Eyre" by Charlotte Bronte.

St. John serves to contrast with the other male characters in the book. Compared with Mr. Rochester, he is as ice towards his love, Rosamond, because he knows that they are not suited for each other and would be unhappy together. This shows his far-sightedness. However, Mr. Rochester is fire, passionate towards Jane and determined to marry her at whatever cost just because he loved her without caring what the consequences were, even though he knew that he was already married to Bertha.
Also, Mr. Brocklehurst was cheap towards Lowood, only allowing the bare necessities to the girls there bu…