INPs Ni is shown in their experiencing of their inner perceptions with great conviction, great sage-like wisdom and sense of knowingness, but they privately and unconsciously manage their Ni, which exists in their id. Unless you direct their attention to their own Ni, they may not even realize they do it. As an INFP, it took me a month to figure out it is constantly on in the background of my mind. INPs often seem quite reflective, spacey, and distracted by their internal world, and this is because they are experiencing the inward intensity of Ni as they get sucked into this function, which can make them feel psychotic. This inwardness is not simply the result of Fi or Ti, but trains of intuitive hunches that go deeper and deeper in to the subject. They can sense the profound implications of certain ideas.
However, they avoid appearing psychotic, prophetic or knowing for they believe that Ni comes off as too arrogant and certain of itself. INPs attempt to get out of this Ni state because their hidden agenda (tertiary function) is Si. They seek to be relaxed, tranquil, and in tune with the subtle charming pleasantries and aesthetics of the physical world (Si), which they can have trouble doing. However, Si and Ni cannot be simultaneously on—when one is on, the other has to be off. However, for INPs, their Ni is constantly on, and that is why their Si suffers.
INPs spend a lot of time in their head creating their inner worldview with Ni. However, they like to use Ni for themselves, not feeling as obligated to share it with the world like INJs, and if they do share Ni insights, it is indirect—they present it via Ne and their dominant judging functions. As rational types they don’t like how irrational Ni presents itself to the outside world—Ni must submit itself to principles via Ti or values via Fi (some sort of “standard”). All sides of the story and alternatives must be presented via Ne in a relaxed manner, and Ni ideas (though felt with a strong knowingness) can only presented as a “could be”, allowing others a sense of choice.
The advantage of a very strong and unvalued Ni (id Ni of the INP) is that they present Ni in an indirect and unserious, and thus harmless “no big deal” matter, and thus people actually are more willing to consider it as it is more palatable.
The disadvantage is that their Ni can have a somewhat negative tint to it. When Ni insights are presented by Ni-valuing types, INPs will unfairly ridicule them with their own Ni. Ni works both positively and negatively in INPs, but when things are going swell INPs are not inclined to talk about Ni, preferring Ne. But when prompted by negative “premonitions”, they will feel inclined to warn people, or when someone is annoying them they will unleash their negative Ni “knowing” insights about them. The id nature makes the Ni come out as unpleasant outpourings from the unconscious. The unconscious nature of the Ni makes their Ni more difficult and way too complex to explain, compared to INJs who can more consciously explicate it in a simpler form. This last part I garnered from Stellar Maze.
In certain ways, as Stellar Maze has pointed out, this id function (6th function) is more powerful than the dominant ego one (1st function). This is because the id/unconscious is experienced as an incredible force. It cannot be as controlled as so overwhelms the being. INJs have the power of more conscious control of the function, but imagine The Hulk here it comes to INPs.
Ni is very much present in INPs’ ideas either in speech or writing, but must be indirectly ascertained. Others do see INPs as wise and highly intuitive and can see both the positives and negatives of their Ni. It is important for INPs to know this. This is because INPs mostly perceive their Ni in a negative light, and thus seek to get away from it (which they attempt to do via Ne and Si). Exploring the world of outer possibilities of Ne, and the small pleasures of Si has an alleviating effect on their intensive Ni.
Ni is like a treasure box in the attic of their mind that needs to be dusted off and unlocked. When INPs start consciously embracing it, Ni can actually be an incredible tool, as it is already very strong. It is the lack of trust in it that makes it seem weak. It would be good to balance out their Ne. Ne will give an endless list of options, but if they allow themselves to tune in and trust their hunches, they will know what intuitively are the best options to take.
*Wait for INFJs to leave the room*
Don’t tell the INFJs, but a good example of an INTP who embraced his Ni is Carl Jung himself. There is a video of him in old age in which he pretty much says that he is an INTP and his life reveals inferior feeling tendencies (Jung on his type), and yet for some reason people really want to argue otherwise, and even say he can’t type himself with the type system he created. Obvious in his writing is a good deal of Ti. He has unlocked Ni in himself, his wise-man function (according to Dr, Beebe). Ni is the wise-man or wise-woman function of INPs. The reason why people argue he is an INFJ is that they don’t understand that the Ni of INTPs is actually very strong. When they choose to embrace it, it comes quite naturally.
If Si is the weakness that INPs try very hard to exaggerate and present to others (and others see right through it), Ni is the great strength that they try very hard to hide (and yet others uncover it). Te, Fe, and Se are so hard to work at for INPs. Pull out that Ni and start to love it!