Each personality type has four Cognitive Functions. Functions put language to the way they process information and make decisions. Each type is referred to by their top two functions. Internal functions are the ones you use in your head, and external functions are the ones you use to interact with the world around you.

The FiNe’s functions are:
1. Fi - introverted Feeling
Although it’s referred to as “Feeling”, Fi is not internal emotions, but rather values that come from within. FiNe’s might experience a deep well of emotions, but this is not the root of Fi. It is a decision making-process that is very interested in determining its own moral code and what the FiNe’s gut instinct tells them is right, which is often based on how they would like to be treated themselves. They tend to be very considerate of others, and may take a long time to mull over their own beliefs to make sure they seem right. The values-refining process can take quite a bit of time and requires mental solitude. Fi generally puts authenticity in high esteem and is repulsed by anything that seems fabricated or shallow.

2. Ne - extroverted iNtuition
Ne is the main way FiNe’s take in information. This means they use their intuition to find patterns, underlying principles, and ideas, and to form connections as they talk, write, or create. Ne flourishes when given new, interesting concepts to consider and consistently seeks out new inspiration from the outside world. For the FiNe, Ne is paired with Fi and “serves” it in the sense that it comes after it in terms of preference. This means that Ne will most often be used to explore values and ideals in all of their facets. Because Ne is extroverted, it primarily works by engaging with outside sources. This may look like having discussions with others who are also open to exploring the possibilities of a topic, or doing a lot of self-expression through writing or an art form. 

3. Si - introverted Sensing
Si is the FiNe’s third function, and it gives a sense of solidity to their Fi beliefs. Si also makes the Fi-led internal world structured and detailed. When it comes to values that they have had adequate time to develop, they tend to have a solid sense of ‘right’ and ‘wrong’. A lot of their perception in these cases is based on their personal experiences. This is because Si places a high value on real world experiences and its impressions of them. FiNe’s store all the interesting experiences and information they gather in their mind in an organized way for future reference. 

4. Te - extroverted Thinking
Te is the FiNe’s inferior function. This function may be their achilles heel, and is inherently not as strong as their other functions because their highest priority and focus is on Fi. Te is a very logic-oriented way of problem solving. It is the side of them that naturally looks to find a better solution to a problem, improve the efficiency of a process, or critique and refine what is already in place. FiNe’s generally prefer only to use Te only when necessary, rather than to make all of their decisions. Overuse of an inferior function can be very draining, and may be unhealthy when constantly given priority over other functions.

Dominant Function and Core of the Internal World:

Introverted Feeling

Fi-dominant types are very warm and caring to those they are close to, especially because they may subconsciously believe that everyone has an inner world similar to theirs. However, they take a while to open up to people, and aren’t likely to approach someone unless that person strikes their interest in some way. Once they let someone into their world, they are likely to keep that connection open as long as harmony remains between the two. For example, if the other person shows themselves to be inauthentic or living out a strong opposition to a value the FiNe holds, the FiNe will retreat from the relationship. As long as those principles aren’t violated, the FiNe will likely be attached to that person for life, whether or not they see them regularly.

FiNe’s are masters of self-care and typically great at putting healthy boundaries in place. They are very empathetic people, so they see the needs of others and want to care for them. However, healthy FiNe’s know that they cannot effectively care for others unless they first care for themselves. They know their limits and aren’t usually afraid of saying ‘no’ when they aren’t able to do something or fit something into their lives.

Fi differs from Fe (extroverted Feeling) because Fe is is focused externally and is constantly asking, “How does the group feel about this?”, whereas Fi is focused internally and is constantly asking, “How do I feel about this?” Once their own needs are met, FiNe’s also tend to hone in on one or two significant relationships. They naturally take care of these people and treat them like family. These people could be a romantic partner, a best friend, etc.

FiNe’s are highly protective of their ‘inner circle’, feeling that those they share the intimate details of their persona with are in some ways part of themselves. They will not hesitate to defend themselves or those they are close to if they are attacked or threatened.

FiNe’s are extremely self-aware and spend a lot of time on self-reflection. They are very concerned with the depth and nuances of their values system and spend a large amount of their mental space clarifying, sifting, and refining their beliefs. This process can be very connected to deep emotions for FiNe’s. They might find themselves laughing or crying at the beauty of a seemingly random object that has meaning to them, while bystanders who notice their reaction might be quite confused at their sudden outburst. For some FiNe’s, their emotions run so deep that there have to have been a lot of feelings building under the surface for quite some time before they will burst forth. They tend to seek out things (movies, books, etc.) that will engage their emotions, because following characters they care about through an emotional journey can be very rewarding.

It’s worth noting that when we talking about Feeling (Fi or Fe) as a cognitive function, we do not necessarily refer to emotions. Emotional experiences or expressions can be related to Feeling (Fe or Fi), but they are not the root cause of the cognitive Feeling. The root of Fi or Fe boils down to a person’s values, meaning what a person thinks is important based on their own conscience and the reasons they believe it’s important. An FiNe’s moral code is derived from what their conscience or "gut instinct" tells them is right, and they generally treat others the way they want to be treated. This Fi value is not based in emotions, but neither does it need to be 100% logical. It is not overly concerned with the REASON behind treating others fairly… It simply ‘feels’ like the good and right thing to do because they themselves want to be treated fairly. 

The FiNe’s driving instinct is to achieve inner harmony by remaining true to themselves, their own values, and minimizing the influence that external factors (societal expectations, and maybe even the opinions of friends and family) have on their values. They may love discussing or even debating their values with others, as long as they are able to remain true to themselves while doing so. After a lengthy discussion, FiNe’s need time by themselves to evaluate the conversation and consider what the other person said and how they might fit it into their value system.

FiNe’s find their own principles to be trustworthy and valuable, and are inherently skeptical of  others that try to impose on them. If something does not line up with their beliefs, they cannot act in accordance with it. To go against their own values is to cause inner discord, which FiNe’s can’t tolerate for long.

FiNe’s can get lost in their own world of trying to figure out what a stranger, who is sitting 20 feet away from them in a coffee shop, is thinking, how their day is going, what their life must be like, etc. They love people watching, but aren’t typically interesting in getting up close and personal with most people as they feel pressured to react and respond appropriately in real interactions. They may even Imagine a conversation with someone rather than actually speaking to them in real life, as imaginary people don’t have demands or expectations of them.

FiNe’s tend to have an active imagination well into adulthood. Fi-doms are very concerned with The Story of/behind various things. For example, they might see a large, sturdy tree and wonder how long it’s been there, and try to imagine the events it’s been around for, or who else sat in its shade, what wisdom might be attached to or inside of that tree, etc. They automatically look for meaning everywhere - in books, movies, a passing remark from a friend, a special cup they like to use, or even why a certain tree was planted in a certain place.

FiNe’s tend to assign meaning to everything. Because they are so involved with and entangled in the depth and nuance of the meaning of everything, and how the meaning of something relates to everything else, it can become incredibly captivated by the right idea or story. When something sparks their imagination, or taps into an aspect of meaning that carries a lot of weight with an FiNe, they become entranced by the story or idea. The process of a story unfolding can be more meaningful to an FiNe than the sum of the story’s parts. 

Second Function and the Core of the External World:

Extroverted iNtuition

FiNe’s have a very abstract way of looking at the world. Ne is their second function, and it makes them naturally oriented toward theories, patterns, and new ideas or principles.

FiNe’s have a world of theories that are swirling around at any given time, and it’s important for them to have time alone in order to develop them. Their best ideas will usually come when they have a sense of inner peace and enough inspiration. Many FiNe’s find mindfulness, meditation, or another form of intentional relaxation to be useful for obtaining peace.

FiNe’s can find inspiration in almost anything, because their Fi finds meaning in everything. As far as inspiration goes, learning interestings things, reading interesting books, taking a walk, or having a good conversation are all common stimuli. For the ideas that have had some time to percolate, they need to have places for output. Whether it’s writing, speaking, teaching, building, designing, or something else, it’s important to have a space to string together their ideas in a unique way. This can also help them to refine and perfect the expression of their ideas. While they may feel like they understand something fully in their head, and they often make great teachers, they may not be as adept at explaining things to others without previous practice.

FiNe’s love novelty. They are always looking for a new shiny puzzle to solve or a new thing to learn about. They can get bored with something after reaching a basic level of competence. Even still, FiNe’s often have one or two things that remain as a thread throughout their lives - the things that are most meaningful to them, which they have never found boring. It’s likely they will eventually become an expert in these areas if they don’t lapse for too long in their study or practice of them.

FiNe’s love considering ideas, possibilities, and the future. They are less concerned with “what is” or the current moment. It can be tough for FiNe’s to savour the moment and to celebrate their successes as they naturally look at what they need to do next.

Third Function and Supporting Role in the Internal World:

Introverted Sensing

Si is all about how real world, 5-senses (seeing, hearing, tasting, touching, and smelling) experiences affect FiNe’s. They value their own experiences very highly, and typically have a very good memory or catalogue of details about their experiences that they deem important stored away. FiNe’s tend to very nostalgic and sentimental about things that hold deep meaning for them. Perhaps they like having a certain kind of cake on their birthday every year because their mother made it for them growing up, or they might be very attached to certain objects that mean something to them. 

FiNe’s value vastly different 'traditions' or rituals from most people, and demonstrate them in less obvious ways. To put it another way, their traditions are often not very ‘traditional’. At times get into a good daily rhythm that they unconsciously follow. it’s easiest for them to keep going on this rhythm in their day to day life and it helps them feel more balanced. However, when something interrupts their rhythm, they might have trouble picking it up again once the interruption ends. 

Their internal world is pretty ‘set’ and solid-feeling as they enter adulthood. A lot of their basic values have been decided fairly early on, and they fall back on these until new experiences, ideas, or realizations cause them to reevaluate certain values. They may consider themselves to be pretty open-minded. However, when faced with a new principle that they have no experience with, they will need a lot of time to themselves to evaluate their stance on the subject. Once they have had adequate time to consider the matter, even if they don’t have it figured out 100%, they feel better knowing that they have reached some level of understanding within themselves.

Si is a very detail oriented function that makes FiNe’s confident in using solutions that have worked in the past, and they can use this to their advantage when necessary to stay organized in their job, at home, or in any hobby that requires detailed organization and quick-solution problem solving. FiNe’s tend to have a good balance when it comes to choosing between applying a new innovation and a previously successful solution. 

Last Function and the Supporting Role of the Internal World:

Extroverted Thinking

Te is a process that allows FiNe’s to take in information from the real world, make quick decisions on what the most effective solution is, and put that solution into play right away. This is the weakest, achilles’ heel part of the FiNe. Although it would be exhausting and unhealthy for them to rely on this aspect of themselves all the time, they can pull out their troubleshooting skills when necessary to get a job done effectively.

While FiNe’s prefer to take their time on decision making, it isn’t always possible or practical. In these situations, it’s useful to have Te so that they can make quick, in-the-moment decisions. Because they are relying on their ‘gut instinct’ Fi internal compass in the background, they can feel comfortable with their decision even if they can’t articulate a solid reason for it at the time. For example, if they have the sense that someone they see walking down the street could be harmful to them in some way, they don’t have time to untangle why they have that feeling. They just know they don’t feel safe next to this person, and the best solution is the cross the street or take a detour in order to avoid them.

In a lot of cases, Te is the protector function of the FiNe. When one of their values comes under attack, they have no problem using a direct, matter-of-fact Te communication style to defend what they feel is right. When they feel so strongly about a subject that they know they must take action on it, they tap into this part of themselves that is powerful and commanding to take a stand for that what they believe is right. Te can also be the part of FiNe’s that tells them to just pick something (a career, a hobby, an outfit, etc) and stick with it, at least for a short period of time. It’s the smaller part of FiNe’s that pushes them to come to a conclusion and be decisive. If it was purely up to their Fi, they would contemplate how they feel about it forever. 

An FiNe who is forced to act out of this Te problem-solving, critiquing side of their persona for a large portion of their time (for work, or parenting, etc) is likely to become burnt out, and might experience decision fatigue very quickly. They generally do best when they can allow someone else to take over the decision-making in at least part of their life. If they must make all the decisions in their job, and all the parenting decisions, and all the relationship decisions, etc., then when it comes time for simple, self care decisions like deciding what to eat for dinner or what route to take home from work, they are already exhausted and will struggle to know what they want. 

FiNe’s best use their Te when there is already a system in place, as it is easiest for them to use the simplest version of Te - critiquing and refining. When something is already in place and needs improvement, it can be easier to analyze it and see the solution. When starting from scratch, FiNe’s might have lots of ideas, but the act of putting systems and and structures of efficiency into place is harder for them.