Is St. John "Marble" Rivers a Sociopath?

It has been far too long, gentle reader, so let's pick the conversation back up.

Apparently in Charlotte Bronte's Jane Eyre, our esteemed protagonist stumbles a bit after deciding to leave Thornfield---and all the potential sin-stained happiness that goes with it---and lands herself at Moor House. In addition to the easy kindness of the Rivers Sisters, Jane is confronted with the Man of Stone himself, St. John Rivers, the humble, cold, unflappable, reverent, made-of-marble cousin who spends about five chapters auditioning Jane for her role as missionary's wife. Jane resists, but just barely. My question is: what the hay, Sinjun? How is it possible for this guy to hold such sway, to literally invade Jane's being in a possessive and not unharsh way? Jane is tough; Jane is self-aware; Jane has experience in repelling unwanted advances. So what gives? In short, what makes St. John Rivers so formidable?

I wonder if we have a convenient comparison at our disposal. St. John is classically handsome, polite, understated, intelligent. In addition, he is religious and wise, dutiful and tireless. He also plays second fiddle to Rochester, at least in terms of their chronological and symbolic significance. Both for Jane and us. If the characters in Jane Eyre were treated as an order of operations, then Rochester's function would always be performed before St. John's, regardless of where the other characters fall. But this should not diminish St. John's influence. On the contrary, he is formidable, which only elevates Rochester's status. But enough of Eddie. This is supposed to be about how Marble Rivers imposes his will so effectively. He never yells (he wouldn't allow himself such a display of emotion) and he demands an almost impossible standard of Jane (he wouldn't allow himself anything less than superior levels of outcome). Jane finds herself literally weeping into her book of Hindostanee as she continues her lessons with St. John. That's crazy! She knows that she will literally die trying to appease him if she goes to India at his side. And she still considers going. That's crazy!

And Jane isn't crazy, gentle reader!

What would a convenient comparison be, then? Who fits the bill as demanding task master? Stone cold and yet motivating to the point of perishing? Clearly symbolism abounds: it is Rochester's Fire, his provocative and self-deprecating manner that wins Jane over, not St. John's Ice, his overly rational and underly emotional capacity for fellowship. Rochester wants an equal; St. John wants an asset. And while his own brand of charisma ultimately fails, it only just fails. St. John could be the ultimate display of a singular and righteous focus, a man of ultimate principle. Or he could be a sociopath, masquerading as a clergyman. I don't throw the term around loosely. Sociopaths can be very persuasive, very charismatic. They can also be very detached, very misunderstanding of typical human perceptions and responses. The text doesn't lie: St. John feels things and then represses them. He knows all about Rosamund's affection and his own reaction to it. So I really don't think he's a bonafide sociopath, nor do I think that Bronte wrote him as one. After all, the book doesn't really go to any great lengths to explore mental illness...