(Spoilers for Person of Interest)
Ni: Finch constantly considers how the Machine could affect the future. Despite the potential problems, Harold builds the Machine because he knows it could save countless number of lives. After the death of his friend, Finch dedicates his life to saving the irrelevant numbers. He’s only distracted from his mission when he is being overwhelmed by despair.
Te: Finch tries to make decisions based off logic, and not just his feelings. At first he ignores the irreverent numbers because he understands that he can’t save everyone. He can be very blunt, even telling his partner Reese that they would probably end up dying in pursuit of their mission.
Fi: Finch tries to keep his feelings private, and they usually only come out in times of great turmoil. He has a strict policy against killing, and refuses to kill even when it becomes necessary for victory. This rule is only broken to save the people he loves, and only then when he’s given no other choice.
Se: Finch isn’t much of athlete. Of course this party due to the accident he had prior to the series premiere. Harold was able to disappear from both his enemies and allies after Samaritan went online. He was only drawn out because his enemies took advantage of his love for Grace.
Outside Factors: Experience extreme trauma before the beginning of the show.