The tertiary function in Myers-Briggs type theory is a tricky function. It has rightly been called “tertiary temptation” because it tempts you sweetly out of your main ego orientation, which is the dominant function. The tertiary function is a function that we have facility with but it is called the tertiary function for a reason, because it should be considered third in priority in the economy of our personality type. It actually shouldn’t be considered at all because it will come as a natural by-product of using our best and easiest functions, the dominant and auxiliary functions.
So, for an INFJ, which is using introverted intuition as a dominant function and extraverted feeling as an auxiliary function, there is a temptation in the introverted thinking tertiary function for them to bypass their auxiliary function in order to stay locked into introversion.
You should develop the dominant and auxiliary functions of your type before you focus on any of the other functions. The tertiary is tricky and it is best to exclude serious activities or professions related to it as a rule. The tertiary is like the hobbyist function, the amateur, it is what you like to do to stimulate yourself and to grow as a person.
The mistake many people make is to pursue what the tertiary function symbolizes outright. It tempts many INFJs into thinking they could be professional computer programmers for example. It is because of their introverted thinking tertiary that they may begin to become interested in machines and how they work and this is where there tertiary is pulling them off course. It is pulling them towards their inferior function of extraverted sensation. As a rule, there is a great fascination with the inferior function but unlike the tertiary, it is something that we feel we are not able to be, and this is true. But, through the use of the tertiary we may be tempted closer and closer, and by subtle degrees, toward the things of the inferior function. This wouldn’t be so bad if we were already very well-balanced individuals who were using our dominant and auxiliary functions on a consistent basis. But most people aren’t.
If you want to be a happy person, then do your first two functions. It is as simple as that. I will use the INFJ as an example. INFJs are naturally good at writing and anything to do with the comprehension of literary elements. I would call this a facility with language and the understanding and communication in a language. INFJs are also natural-born psychologists, having the ability to understand other people’s characters and motivations extremely easily. They would have to make an effort to not be good at these things.
The problem that INFJs have is that they are attracted to the prospect of being intellectuals in the cold and austere way that an INTJ is naturally good at. INFJs are attracted to the idea of sitting in some remote corner in isolation and figuring out how the world works.
The thing that they wish to bypass is their extraverted feeling, which would entail going out into the world, or at the very least, including the human element in their investigations. INFJs are humanists by nature and they have a natural bent towards humanistic subjects and themes, such as we see in drama and literature. But, INFJs are tempted by their introverted thinking into dealing with things rather than people. This won’t work for them. They are tempted into an objective and impartial analysis of situations and people. Many INFJs begin to feel that they are introverted thinking dominant types the more they travel this road. However, as a rule, this will lead to their disintegration and downfall. They are not built to be cold and remote philosophers. They are not INTJs.
INFJs are people that need people, in one way or another. They wish to escape this but it is not in the cards for them. INFJs cannot ignore their feeling preference. Another way to say it is that they are tempted to be scientists when they are really artists.
Now, it is tricky because INFJs do have some facility with the theoretical aspects of science because of their dominant introverted intuition when paired with their tertiary introverted thinking. This is the “pure theory” combination par excellence. The problem is that the sciences as a rule tend to ignore the human element of their investigations, that is, the feeling element.
INFJs have a real gift for human expression, probably more so than any other type. The reason for this is because of their auxiliary function of extraverted feeling. The auxiliary function is like a present waiting to be unwrapped. In some ways, the auxiliary function is the greatest gift of any given type. The primary reason for this is because you can do something with it. You can produce a product with it. The dominant function is more of an ego-orientation function such that it is too busy keeping things together for it to directly do anything. It is like the operating system in a computer. It is scheduling processes and making sure other processes don’t step on other ones and making sure things that are scheduled to happen get done on time. Another way to put it is that the dominant process is an ingoing and receptive process while the auxiliary is an outgoing and transmitting process. This is true even for extravert dominant types.
Anyway, the INFJ with their extraverted feeling will have the spotlight for anything related to this function and will do it better than any other type, when combined with their dominant. This means they are excellent at transmitting in human terms the information that they are receiving via their introverted intuition dominant function. Much of this information is abstruse and difficult to understand, even to themselves.
But, magic happens when an INFJ chooses to express themselves through an extraverted feeling medium. This would be writing, image-making, music, and in short, anything that is artistic. Conversely, the moment the INFJ starts thinking, “Hey, maybe I could systematize these abstruse thoughts into a closed system or philosophy of some sort”, they are on the road to ruin.
Now, this systematization can happen for them but it will only happen as a byproduct of doing the activities that are most natural to them. If they go directly for the closed system they are going to get stuck and become very unhappy. It is tricky because it does feel good at first. The tertiary is like a dessert or a delectation. It is meant to be used sparingly and as a fitting end to some main course. Pink Floyd said it best, “How can you have any pudding if you don’t eat your meat?” You can have your tertiary function but you must eat your main course first. You see how that works?
Another way the slippery tertiary function will come into play with INFJs is in their beloved writing itself. Here they will become obsessed with the most perfect expression of what they are trying to say in the form of getting stuck on one word. This is an introverted thinking thing to a large extent. Introverted thinking is very concerned with proper definition of terms. And so a struggle will ensue between extraverted feeling and introverted thinking. Extraverted feeling needs to flow in expression and achieves the exact opposite effect in its writing than the introverted thinking style of writing, Extraverted feeling paints an overall picture or atmosphere with the words they use that convey in their entirety the thing that the INFJ wants to express.
There is something elusive in this way of communicating because you may not be able to point to any one term, phrase, or paragraph that is responsible for the magic. There will be some subjective element there that can’t be adequately reduced into its constituent parts. But with introverted thinking stepping in, there will be the temptation to do this. This can only be done as an afterthought with INFJs. It will come of its own accord when they have done their extraverted feeling duties.
The introverted thinking style of writing is akin to legal writing, where all terms and conditions are rigorously defined. INFJs will get hung up on the proper definitions of the terms they are using but they are advised to keep rolling forth. The only requirement that extraverted feeling has is for fluidity and flow. It wants to be prolific. If you are an INFJ, let it. Let the thing that you want to express emerge. Don’t give in to the introverted thinking temptation to block the flow because of a hang-up it is having about the veracity of a particular term. It is a recipe for disaster.
Disaster for an INFJ is to let the search for an absolute and objective truth impede their emotional flow. Many INFJs have not turned on their emotional flow to begin with. But, they should and they must. Once they do they will be happy and see how easy it was for them to be happy, which they couldn’t see when they were caught in the immense abstruseness of their tertiary introverted thinking paired with their dominant introverted intuition. If INFJs get locked into that loop, it is like being promised heaven, but always ending up in hell.
It will feel superficial at first if you are not used to this type of expression and you will probably want to abandon it in favor of your introverted refuge in an ivory tower . You will feel like you are missing great expanses of information in your communication and that you have glossed over important facts, points and considerations. But, that is okay. Extraverted Feeling is supposed to be superficial. All extraversion is superficial relative to introversion. However, this is where the balance is necessary for those INFJs locked into their double introverted function loop.
It will feel good to use extraverted feeling but you may distrust this as you have been accustomed to the belief that anything worth attaining entails suffering and extreme complexity. However, you are unlikely to attain anything at all if you are locked in this loop. It is like the carrot leading the donkey forward. There is the promise but never do you get closer to what it is that you wish to attain. The only way out of this debacle is to use extraverted feeling. It is that simple.