Dominant Introverted Thinking [Ti]: The Doctor’s internal logic is his greatest asset. The Doctor believes he can solve any problem, and is able to look beyond the facts, allowing him to come to creative solutions. While his logical reasoning often saves the day, it also sometimes lands him in hot water with people because it causes him to be extremely blunt, and he tends to comes across as insensitive or rude. The Doctor is naturally curious and always seeks to understand the hows and the whys in every situation he finds himself in. He is able to make detached decisions based on rationality rather than emotion. He’s okay with allowing Gwyneth to sacrifice herself because the good of the many outweigh just one person’s life. When he first meets Rose, he’s interested in her theory, even though he knows it’s incorrect. But he’s interested in her logical process and how she arrived at her hypothesis (that the Autons are students playing a prank). He’s impressed by her analysis of the situation and declares that it makes sense, even though her assumption is wrong. The Doctor usually thinks to himself and only reveals details that are entirely necessary. He doesn’t want to explain anything to Rose at first, and only gives her brief snippets of information, until she gradually begins to prove herself to be useful to him. The Doctor wants people to think critically about the world around them. He’s frustrated when they don’t open their minds. “And no one’s going to stop you because you’ve bred a human race that doesn’t bother to ask questions. Stupid little slaves, believing every lie. They’ll just trot right into the slaughter house if they’re told it’s made of gold.” The Doctor always approaches things reasonably. When Rose wonders if he’s going to scan for alien tech after a crash, he simply responds by saying, “Rose, it hit the middle of London with a very loud bang. I’m going to ask.” The Doctor needs to know how a phone that wasn’t actually a phone was able to ring, and becomes obsessed with getting answers about it from Nancy. It’s not enough for him to know that human DNA is being converted to create these “things.” He also needs to know why and what the point of it is!
Auxiliary Extroverted Sensing [Se]: Although the Doctor always has ideas, they’re typically pretty grounded and based on what he knows is possible. He doesn’t really get caught up in flights of fancy (like a couple of his later incarnations). The Ninth Doctor is also much more conscious of fitting in with the time period than some of his regenerations, and tells Rose that she must blend in with their surroundings. He tells Rose that he travels in order to see and experience. Not knowing what’s going to happen is fun and stimulating! He wants to watch events unfold and be part of them! It frustrates the Doctor when humanity proves incapable of believing in what’s right in front of them, especially when they seem to have no difficulty believing in things that can’t be seen or proven. “You’re happy to believe in something that’s invisible, but if it’s staring you in the face, nope, can’t see it. There’s a scientific explanation for that. You’re thick.” The Doctor tends to enjoy the moment without spending too much time brooding over the past or worrying about the future. He takes things as they come and enjoys adventure. He encourages others to just dive in and start doing. “The thing is, Adam, time travel’s like visiting Paris. You can’t just read the guide book, you’ve got to throw yourself in. Eat the food, use the wrong verbs, get charged double and end up kissing complete strangers. Or is that just me? Stop asking questions, go and do it.” The Doctor is so focused on the present that even the immediate past doesn’t have much impact on him. Somebody just died, but hey, they’re already gone. He can’t fix that, but he can prevent more people from dying now so that needs to be his primary objective.
Tertiary Introverted Intuition [Ni]: The Doctor has very good intuition. However, he tends to follow one of his instincts until it proves incorrect, rather than juggling a bunch of hunches at once. The Doctor is able to see how events will unfold and understands motivations. “That’s why the Slitheen went for spectacle. They want the whole world panicking, because you lot, you get scared, you lash out… You get the codes, release the missiles, but not into space because there’s nothing there. You attack every other country on Earth. They retaliate, fight back. World War Three. Whole planet gets nuked.” While he is usually able to understand how events will unfold and is able to arrive at correct conclusions, he sometimes fails to understand what’s really going on in a particular situation (such as trusting the Gelth and trying to help them, only to realize they were actually the enemy). With no prior knowledge whatsoever, the Doctor is able to guess that Nancy lost someone and wonders who it was. Then, he is able to intuit that her little brother was actually her child, but since she was an unwed teenager at the time, she was forced to pretend that she was his older sibling instead of his mother. However, he does sometimes fail to relate things to the big picture. When the Doctor realizes that the words “Bad Wolf” keep turning up everywhere he and Rose go, he mistakenly writes it off as a big coincidence and doesn’t think much of it.
Inferior Extroverted Feeling [Fe]: It’s very difficult for the Doctor to open up and talk about his feelings. He doesn’t like to talk about the Time War or his feelings about it. He has a habit of getting completely immersed in the mystery that he forgets about the people who are involved. When he first meets Rose, he forgets all about Mickey, and appears rather indifferent to her feelings about losing him. However, he claims that because he’s trying to saving the entire planet, it’s difficult for him to focus on just one individual. He fails to tell Rose that there is a possibility that Mickey is still alive, and when she admonishes him for this, he scolds her, telling her to “keep the domestics outside” (which he says on more than one occasion). The Doctor lacks tact and doesn’t really concern himself with protecting other people’s feelings. He tells it like it is, however unpleasant it might be for those around him. The Doctor’s sense of morality is more malleable than Rose’s. She is completely against allowing the Gelth to use the bodies of the deceased in order to save their species, but the Doctor is okay with it if that’s what it takes to keep them alive. The thought is appalling to Rose, but the morality of the situation doesn’t weigh heavily on the Doctor. “Not decent? Not polite? It could save their lives.” To him, it’s simply recycling. In order to get Rose to see things in a new light, he asks if she carries a donor card, and while she says she does, but that this is different, he reponds by saying “It is different, yeah. It’s a different morality. Get used to it or go home. You heard what they said, time’s short. I can’t worry about a few corpses when the last of the Gelth could be dying.” He often refuses to get involved with Rose’s personal life and is unwilling to spend time with her mother. He doesn’t care if Jackie wants him to come over. He has no interest in wasting time with her when there’s an entire universe to explore! The Doctor can be somewhat callous about other people’s losses, telling a man he can mourn his father later, because there’s nothing they can do to help him now. He’s gone, we’re here, we need to focus on saving our own hide. Although the Doctor isn’t great with relating to people in one-on-one situations, he does care about people and wants to help them. He’s overjoyed during the one occasion where he is able to successfully save everyone.
Note: I considered 7 for the Doctor, but I think that’s because fives can sometimes take on characteristics of sevens. I might change my opinion on this, but for now, I’m sticking with 5.