He Died of His Wounds Long Ago: Thorin (in the movie) an ISTJ?
I'm not as good at MBTI typing as most, but I saw telltales throughout the movie I couldn't ignore. So don't expect this to be textbook.
I am an ISTJ as well, but this isn't just a case of "wishing a cool character into your type". I can't stand it when people do that. I merely saw a lot of things that were either A) all too familiar or understandable, or B) pretty textbook _STJ behavior and rationale.
There was that moment in the movie when Thorin firmly stated that Azog had "Died of his wounds long ago" even though he had only seen the pale orc carried away from the battle. He cut the left arm off of his enemy. His enemy was carried out of sight screaming. He never saw his enemy again (until decades later). So he took the information he saw and slowly accepted it as fact. And once it was a fact, suggestions otherwise seemed unfounded and therefore, uncreditable. Yes I just made up a word.
He is intensely loyal to the ideas of his family, his nation, his heritage, and the world that once was. He is especially defensive of Fili and Kili, his nephews. He took his sister-sons under his care when they were orphaned, and by all appearances taught them what he thought was essential and becoming of the Line of Durin. His first reaction to seeing them in Bag End is to smile lovingly (a rare thing for Thorin), and his first reaction to half the company nearly being crushed by boulders is to cry out frantically the name of Fili, more concerned for him than any of the others. The brothers both love their uncle with equal loyalty, though Kili (the younger) seems to always be looking for his uncle's nearly impossible to gain approval.
Thorin hates elves on principle. The Mirkwood elves his people had trusted gave them no aid when their need was dire, so therefore elves as an entire race are to be despised and never to be trusted. That and he doesn't just hate them because of their broken trust, but just on the principle that he is of the dwarven race and they are of the elvish race.
He takes his heritage immensely seriously, and has an incredibly proud and lofty bearing, but doesn't ever pat himself on the back for doing something right or well. Nobody gets a gold star from Thorin, not even himself. Straight and simple. "Is everyone alright? Good. On to the next task. Don't do anything stupid or soft."
He has a very methodical, exact, one-by-one combat mode, but then he has the one notch up after that...
...where he is in chaos mode and almost berserk. Sort of pushed over the edge and has a wild abandon, just one goal left in his mind. It takes a few sticks of dynamite to get him to this point, but once he's on the war path, he stands aside for nothing and no one. Hellbent is a word that comes to mind. Which is very similar to an ISTJ pushed too far.
I was conflicted at first whether or not he was an I or an E, but then stopped and considered. He spends a lot of time physically standing apart from the company, and often takes time to stare moodily off into the distance absorbed in his own thoughts. He also gets snappy with his companions if they become overly chatty, loud and nonsensical, or get too far off topic (i.e., the dinner scene at Bag End in the beginning of the movie). Not a particularly social fellow. In fact, I'd say people stress him out.
He's very serious. To the point where the others drop into silence from their merrymaking as soon as he knocks on the door. He doesn't tolerate anything he considers nonsensical, silly, wasteful, or witty, especially when there's a job to be done. Even if there's not something pressing, he has a hard time letting things carry on. However, he does have a sense of humor, and when it surfaces, it is usually something subtle or sidelong that was prefaced by a question he already knew the answer to (i.e., asking Bilbo "Axe or sword?"). But generally he's very much a work first, play later type of guy.
He speaks mostly when giving orders, explaining, informing, or defending his ideas, which he considers to be factual and not egotistical. Not many wasted words, and not much of an initiator for small talk or encouragement.
He gets irritated with Gandalf for challenging his plans, because he views them as more informed and practical than what Gandalf suggests. Stubborn as a mountain. He becomes furious when Gandalf berates him for hating the elves of Imladris--furious because Gandalf is trying to pry him away from his preexisting reasons and principles. He hated that his reasons were doubted, and he hated that he was being called a fool for clinging to family and history instead of taking in a potentially helpful ally.
He judges Bilbo as soft, inexperienced, unable to pull his own weight, and an outsider to his company. It is nearly impossible to clear Bilbo from that category in Thorin's mind until the final scene. But that will come back later in the story, don't worry. Bilbo is permanently judged, though sometimes Thorin doesn't even realize it.
Throughout the movie Thorin is quick to blame Bilbo more than others for mistakes anyone could make, and projects principles and ideas he doesn't like onto him--sort of a scapegoat of sorts. Unhealthy ISTJ behavior.
In conclusion, I think Thorin shows a ton of ISTJ-like traits. I have not seen him conclusively typed before, so I would like to put my vote forward.
