Determining Function Axes, Part 2

Michael Pierce is a contributing guest writer for CelebrityTypes. As always with guest writers on the site, Pierce’s piece represents his own insights and type assessments and not necessarily those of the site. In this article, Pierce elaborates on the concept of function axes and how to determine them, expanding on Part 1 of this series as found here.

By Michael Pierce

When setting out to determine someone’s type, don’t think of the functions as eight individual, separate functions, but as four axes or rods. One of Jung’s influences was the Greek philosopher Heraclitus who believed in the unity of opposites. He is credited with saying, as one translation puts it: “The road up and the road down are the same road.” We see this idea reflected in the dichotomies of Jung’s typology. Se is the opposite of Ni, and Ne is the opposite of Si, but because they are true opposites they don’t operate independently of each other. They are rather two opposing poles on the same rod, or two different directions on the same road. Ni is not an individual idea that is just very different from Se. Rather, it exists by virtue of Se and vice versa: As Jung would have it, each has no meaning apart from the other. Likewise, Se has no meaning without Ni. Under this mode of conception, any pair of opposites is thought to exist by virtue of the other: If there is no concept of white, then we can’t comprehend that everything is actually black. Blackness would be without meaning if we can’t have things otherwise. As such, no matter which direction on the road is preferred, there are some characteristics of the road itself that manifest in a person’s psyche.

With that said, I will offer the characterizations typical of each axis.

The Se/Ni Axis

The Se/Ni axis represents an intense perception, one that tends to over-commit or over-analyze one area, but can gain a surprising depth of insight in that area. For instance, the INTJ’s tunnel-vision drive, the ENTJ’s brutality and directness, the INFJ’s devotion to creating a holistic system, the ESTPs directness in overcoming challenges, or the ISTP’s incredible focus.

The motion I imagine with Se/Ni begins as narrow and pinpointed at the object, representing the direct focus on the object itself. This expands as we retreat into the subject’s psyche, where that one object is expanded into a fuzzy, associative image that is compared with the hundreds of other impressions and fragments in the psyche. In this way, the Se/Ni axis is intensive, or magnifying, taking inspiration from objects themselves and figuring out all of their subjective possibilities, rather like an overhead projector displaying an enlarged but fuzzier image of the object. With ESTPs and ESFPs, the focus is on the object itself, while with INFJs and INTJs, the focus is on the fuzzy image, the subjective possibilities.

The Ne/Si Axis

The Ne/Si axis represents a multifaceted, sweeping perception that tends to under-commit and bounces around, but which gains a surprising breadth of insight. For instance, the ENTP’s multifaceted inquiries, the INTP’s search for multiple applications for one abstract system, the ENFP’s wanderlust and resourcefulness, or the ISTJ’s thorough waterproofing of their procedures.

The motion I imagine with Ne/Si begins as stretched, fuzzy but associative, representing the indirect, intuitive relationship with objects. This narrows and focuses as we retreat into the subject’s psyche, where the stretched sweep is pinpointed and directly examined, comparing it to other directly examined impressions. In this way the Ne/Si axis is meticulous and examining, making detailed and thorough record of their creative, associative perceptions of the world, rather like a telescope that takes a fuzzy distant object and shrinks and sharpens the image. With ENTPs and ENFPs the focus is on these creative perceptions, while with ISTJs and ISFJs the focus is on the recorded details and thoroughness.

The Te/Fi axis

Te/Fi represents the road between logical judgments based on objective data, to valuations of things based on subjective sentiments. It is the motion between an outside world of outlines to an internal world of shading and values, or a cold, uncaring outside world compared to the warmth within the individual. To illustrate, the Te/Fi axis represents the struggle of a lone individual against a freezing wilderness, employing whatever means necessary to survive, and doing everything they can to keep warm, to make their warmth known in the world and push back the encroaching ice. It retains a nexus around the individual. For instance, the INTJ’s image as a lone visionary, the ESTJ’s prioritization of responsibility over anyone else’s values, the INFP’s championing of their dream world, or the ESFP’s spontaneity and love of performing.

The Fe/Ti axis

Fe/Ti represents the road between valuations based on objective sentiments, to logical judgments based on subjective principles. It is the motion between an outside world of shading and values to an internal world of outlines, or a hot, sultry, caring outside world compared to the distinguishing coolness within the individual. However, to illustrate the Fe/Ti axis I’ll use a different image: It is rather like someone lost in a foreign country that speaks an entirely foreign language, and the journey of discovering and integrating the logic of the language into oneself so that you can experience the warmth of true interaction and join with the people: The struggle to balance the inner ice with the outer sun to match the temperature of those around you. It retains a nexus around harmony and the equivalence between the individual’s inner cognition and the other world. For instance, the ENTP’s inquiries to discover objective truth, or the INTP’s relentless abstraction, the INFJ’s holistic theories of the world, the ISTP’s quest to master a technique, or the ENFJ’s appeal to the values of others.

Watch this piece as a video here.


  1. This was a frustrating read. In order for me to absorb information, I need to care and I care when that information has meaning and purpose. What’s lacking here is the human element. The heartbeat.

    What I’d like to see in future articles are stories. Tell me the story of the INTJ who concentrated on this because he has Ni and the ESTP who concentrated on that because she has Se. Have them work alongside each other, functions bumping into each other but also appearing strangely alike. From this story, I would see how their functions are on the same axis, but on opposite ends.

    In other words, do more showing than telling. Although you did use similes, similes zoom in, whereas I need to zoom out first before I can appreciate them.


  2. Gracie

    I agree, stories for each type would be fascinating — especially first-person viewpoint stories. :)

    The problem though, in my opinion, is that it would still be quite “cold” and lifeless, because the “characters” representing the types would need to be flat two-dimensional “skeletons” with no skin — abstract representations — rather than fully developed 3D characters. Psychological type is actually only one small facet of the overall person, even when dealing with fictional characters.

    Making fully rounded characters you care about will require a lot of superfluous information, which is not only useless for the purpose of explaining typology, but will actually distort the points — real people are contradictory, with lots of different facets to them, and have tonnes of stuff going on in their psyche which isn’t type-related.


    Still, I agree it would be great to get some concrete examples of how the functions would work in realistic situations. :) I’m half tempted to do it myself haha. :D

  3. I disagree with the above commentators. Michael Pierce is doing an excellent job with explaining the Jungian functions in a rational and structured way.

    Jungs work is already heavily subjective and though to grasp in the original, nevermind the english translation. Most people, albeit familiar with Jung and MBTI, lack proper understanding of the underlying framework. Pierce is presenting that framework in an easily acessible manner. His work is important in this community of shallow knowledge and faulty understanding.

    Eventually, it might move us away from nonsense like ‘I’m shy, I must be an Introvert!’ or ‘I’m an INTJ, I really am!’ and towards something more profound and tangible.

    But then again, most people love the ‘What socks does each type prefer?’ kind of posts. Sprinkle some Cumberbatch gifs on top and you’re on your way to stardom in online typing.

  4. @Rachel Wood

    I’m fine with concrete examples of functions working in real life, too. What I’m trying to avoid is for abstract information to be decoded incorrectly. Showing exactly what you mean, in say 3 examples, would help reduce mistyping.


    Stories and concrete examples can be rational and structured. Yesterday, I discovered Michael Pierce used a story format to compare NTPs and NFJs on YouTube. He did so without resorting to tired stereotypes. Shallow knowledge and faulty understanding are exactly what I’m trying to avoid. It’s easy to think you’re interpreting an abstract concept correctly when you’re not, so including a story or about 3 examples would help with those misunderstandings.

  5. I’ve explained Se/Ni and Ne/Si like this:

    Se/Ni is like a bunch of balloons tied to the ground. They can move around and touch on a bunch of different things but they still keep the main topic in the back of their mind.

    Ne/Si is more like a monkey swinging from branch to branch and will have no recall as to what the original topic was.

    Si/Ne will bring up the same topics again and again, and will somehow find a way to bring the conversation to that topic no matter where the conversation started.

    Ni/Se will focus intently on one abstract topic and dig as deep as they have to until they’ve reconciled it with reality.

  6. these parts of the text makes a lot of senses:

    “To illustrate, the Te/Fi axis represents the struggle of a lone individual against a freezing wilderness, employing whatever means necessary to survive, and doing everything they can to keep warm, to make their warmth known in the world and push back the encroaching ice.”

    “to illustrate the Fe/Ti axis I’ll use a different image: It is rather like someone lost in a foreign country that speaks an entirely foreign language, and the journey of discovering and integrating the logic of the language into oneself so that you can experience the warmth of true interaction and join with the people”

    but other parts were highly subjective and hard to understand.

  7. I think of the ni/se and si/ne axis using the hare and the tortoise in a forest:

    Si=the tortoise
    Se=the hare
    Ne=the hare who’s invented a ship that breaks down near the end, who stays in the real world and builds multiple ships during the race
    Ni=the tortoise who imagines a singular spaceship idea, takes ages to build it and then when he does it zooms off beyond the forest and into space

  8. @Luke

    I imagine it would be more like this! :D

    Si: learns all kinds of survival techniques in preparation for the forest. Studies maps of the area beforehand. When the race starts, makes a steady progression towards the finish line. Eventually, he reaches the end.

    Se: does little preparation beforehand. When the race starts, heads quickly in the direction of the finish line without needing any idea of what’s in his path. He’ll deal with it as it comes, and will enjoy the experience too! Eventually, he reaches the end.

    Ne: will do research beforehand – well, he’ll plan to, but he’ll get sidetracked and start learning about random forest-related topics that couldn’t possibly help at all in this specific situation. When he starts the race, will head directly towards the finish line, but will often notice things that relate to what he’s read about during his research. Then he’ll come up with some half-baked theories while walking about why he’s seeing some features in this forest, but not others. Then will realise that while thinking about these things he’s gotten completely lost.

    Ni: does no preparation beforehand. When the race starts, begins to make cautious progress in the direction of the finish line. Gets an inner “hunch” about the necessary path to take, but no idea of the details. Gets an intuitive idea that this race has a universal significance – if he doesn’t reach the end, it goes against nature/God’s will. He MUST reach the end. Ends up getting lost due to not focusing on the environment.

  9. In summary it’s like sensation sticks with the race, intuition goes in a different direction, sweet :-)

  10. Thanks to Michael Pierce and CelebrityTypes, I have a better understanding of all the functions in terms of axes:

    Fe/Ti = following a higher principle.

    Its just a question of WHAT KIND of principle are you living by. Those based on objective values and sentiments (Fe) or personal logic(Ti).

    Te/Fi = individualism.

    Fi is aware that values and sentiments are personal and everyone is entitled to them. Te knows because nobody is cut from the same cloth, objective, impersonal standards are applied to see where in the hierarchy these people fit. Also, Te adapts to objective facts to achieve logical goals in the world which makes a person stand out from other people.

    Se/Ni = Intensity. Its just depends on whether its intensity of immediate experience(Se) or of a vision that had been condensed from other experiences into one thing(Ni).

    Ne/Si = Curious yet careful. Ne considers all possibilities. Si considers how some of those possibilities relate to the person’s impressions of them.

  11. “This was a frustrating read. In order for me to absorb information, I need to care and I care when that information has meaning and purpose. What’s lacking here is the human element. The heartbeat” and many agreeing.

    This is so interesting, how people differ. Pierce’s explanation was the ONLY one that made me understand the functions, before that I searched everywhere but it didn’t make any sense, different people saying things that didn’t match and the whole theory didn’t fit.
    Pierce as it seems is INFJ, and so am I. Which is interesting because for the most part I here people complaining I am “too impersonal”.

    If you like the examples -> even in my letter for college, they said: “it’s a great letter, but… but it’s so impersonal”. For me it was very personal, because it was showing my worldview and my theories. My sister wants me to “open up”, talk about my life. She doesn’t see that for me opening up is talking about my theories and discoveries, and how my internal system works, not who I am seeing. And we both get frustrated, she doesn’t value my explanations about my internal system and I don’t value the life accounts. Another example, I created online tests and I gave some friends to test it first, but then they complained they couldn’t understand what I was asking because it was too objective and impersonal and they couldn’t relate the theory to their lives or behaviours.

  12. @Aline This is Michael Pierce — you’ve hit the nail right on the head. That has been my exact experience throughout life. Thank you!

  13. MBTI is a technical theory. If reading technical things frustrates you, then why are you reading it in the first place? Any speaking about function axes requires a high degree of abstraction to be accurate, so either engage the topic, or show that you can understand it first before criticizing something. Exclaiming that it’s dry and dull to you is not a criticism, because it’s not constructive. Do you have a theory on how to make it less dry, and less dull? If so, please share it. Otherwise, consider expending more effort rather than demanding everyone else expend it for you.

  14. Hello, I appreciate the articles and discussions. However, I disagree with using the term “opposites” or “axes” to describe the pairs listed above (Ne/Si, Ni/Se, Te/Fi, Ti/Fe). I believe “complementary” is a more accurate term as they are used in concert with one another. The true opposite function pairs (i.e. “can’t be used at the same time”) are Ne/Se, Ni/Si, Te/Fe, and Ti/Fi. Like points on a compass.

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