As with "Wuthering heights" I pay most attention to an almost insignificant character, Linton Heathcliff, in "Jane Eyre" I am most 'fascinated' by St. John Rivers.
On 1 hand, it's because he's a foil for Mr Rochester. While Rochester is ugly, grave, grim, stern, moody, irritable, proud, harsh, grumpy, intimidating and can even be lustful and cruel, at least in the past..., St. John Rivers is remarkably handsome (the kind of classic beauty), polite, kind, calm, reserved, pious, duty-bound, restrained, composed... Rochester is fire, St. John is ice. But as time goes by, Rochester turns out to be a good man, fiery and passionate, a good man in spite of his faults and wrongdoings, St. John is unveiled as an austere, repressed, cold, hard-hearted man.
On the other hand, such a character is fascinating himself, without the contrast. He reminds me of 2 persons.
1st is a man by the name of H, an acquaintance of mine, dull and insipid, a man for whom concepts such as 'pleasure', 'rest', 'enjoyment' simply don't exist. These 2 men are slightly different, in their priorities- H's is work, St. John's is serving God or doing something useful for society and human beings, but they resemble in their inability to rest, to relax, to enjoy, to gain pleasure from anything other than work. St. John feels displeased with what he sees as Jane Eyre's idleness and purposeless existence.
2nd is Karenin in "Anna Karenina" by Tolstoy. St. John expresses no sadness over Miss Rosamond Oliver's marriage, which I believe he would feel ashamed of expressing, and afterwards, all feelings in his eyes are selfish and insignificant and inferior to the love of God, therefore he conceals his emotions and wears a mask of calmness and indifference, and at the same time, disregards other people's feelings. And in doing so, he believes himself to be moral, pious, virtuous and dignified, like a Saint even, thus superior to others, and he's unable to find himself in the wrong and unable to see his own faults. He doesn't realise the ridiculousness of his proposal to Jane, nor of his attempt to force her to become his wife, while making very clear that he doesn't love her 1 bit. And even though Charlotte Bronte doesn't dig deep into St. John's mind as Tolstoy does with Karenin's, one can see that St. John never finds himself wrong, heartless and inconsiderate (and sexist). Sometimes such people can even be more cruel than those who are perfectly aware they're doing evil, as people like St. John and Karenin see themselves as some kind of saint, act according to some principle, some higher cause, some supreme being, and feel convinced what they do is undoubtedly good.