In another essay, I created a simple dichotomy: Si and Ni created systems for dealing with problems, whereas Se and Ne dealt more in the moment and were more about getting the "feel" or the "experience" correct. For that other essay, see:

This is another set of personal observations along the same line. (For the tl;dr version, see the last two paragraphs.) I think one can create the same kind of dichotomy with F and T.

For example, taking Fe vs Fi: Fe-users are "in the moment" and are kind of like the firemen of emotions: They handle people and deal with emotional situations in real time. In contrast, Fi-users are more about analyzing feelings and coming up with systems (values, ethics) for handling emotional situations.

Meantime, Fi-users and Fe-users may be poor at each other's task. Fe-users may be poor at handling their own emotions; they're so used to operating in "fireman" mode in real time, that they tend to put off to the side non-urgent matters like their own feelings, and may never get around to analyzing them; they may find themselves spent and exhausted due to this kind of neglect. Similarly, Fi-users may be so used to analyzing emotions at their leisure that they are neglectful of the emotional demands of people in the immediate world around them; they may find themselves lonely and cut off from the world around them.

Nonetheless, if we're talking about about people with Fi and Fe in their top two functions, then this kind of specialization usually isn't a problem. People with Fi and Fe in their top two functions are usually adept enough at playing off the differences between the two functions that the dichotomy doesn't usually lead to trouble on a daily basis. The main thing to notice here is that Fi and Fe do indeed represent a dichotomy. The demands that these two functions make on the individual are separate and often competing. To be good at Fi often means disregarding to some extent the demands of Fe, and vice versa.

The same schematic can be constructed for Ti and Te. Ti is about constructing systems for handling tasks: Logic, engineering, legal systems, etc. By comparison, Te is about handling tasks in "fireman" mode, quick and dirty; it's about breaking through obstacles and getting things done, by hook or by crook. And so on. To be good at one function may mean being bad at the other. But people with Ti and Te in their top two functions are usually adept enough at playing off the differences between the two functions that the dichotomy doesn't usually lead to trouble on a daily basis.

So where does trouble arise? When these functions appear in the lower functions.

For example:

INTPs and ISTPs have Fe in their Inferior. That makes them Fe-users. Personally, I find them to be astute observers and commentators on Fe conventions in the world around them. For example, look at the comic strip "Dilbert": It's written by and for nerds, but in fact much of it is about the craziness of social interactions and conventions. There's actually a lot of keen observation and social commentary there. I myself am an INFP: As an Fi-Dom, I find that INTPs and ISTPs are far better at noticing and commenting on Fe in the world around them than I am.

So why are emotions such a problem for INTPs and ISTPs? I think it's because they conflate Fe and Fi together. That is, they see an Fe occurrence in the world around them and they consider how to react to it; but then they experience their own emotions brought up as a result (irritation, sadness, fear, etc.), and that freaks them out: They now have two emotional components to juggle--the emotions of the outside world and their own emotions welling up from below. They don't understand that Fe and Fi represent a dichotomy: Generally you're supposed to prioritize one and put the other aside for the moment. They are two separate things. But INTPs and ISTPs try to handle them both simultaneously and juggle the interaction between the two, and they end up shutting down.

I see something similar happening to ESTJs and ENTJs (Fi-Inferior): They are actually excellent observers of Fi. But they lose it at that point where they try to manifest their Fi values in response to emotional situations in the world around them (they try to conflate Fi and Fe). They don't understand that the two are separate processes and have to be handled separately.

As for Te and Ti in the Inferior:

I'm an Fi-Dom (INFP), so I have Te in the inferior. I've always felt that I'm an excellent observer of Te organizational systems and even kind of have an affinity for the practicality of Te environments like the military and large bureaucracies. But when it came to Te tasks in my immediate environment, I often shut down due to conflating Te and Ti, resulting in blowing a simple task way out of hand. I see a leaky faucet, and intellectually I know it should be simple to repair: It should just require a $1.50 worth of parts (washers) easily obtained down the road at a hardware store. But then I start worrying what will happen if the problem turns out to be bigger than a washer. Do I have all the tools necessary? If this is going to start happening on a regular basis, should I buy some books and a whole toolkit of plumbing tools and supplies so that I can deal with every possible eventuality? Maybe it would be better to replace the faucet outright. In fact, all the faucets in the house are old--if this is going to be a regular thing, maybe it's best just to replace them all at once. And so on and so on, until the problem seems unmanageable. And it's just a leaky faucet.

So across the years I've learned to strip out the Ti fears and get back to the individual Te task at hand: Do things quick and dirty. Don't blow up the problem into something bigger than it is; just focus on the problem immediately at hand and deal with that. And then subsequently at some later date I can delve more into plumbing as a broad Ti discipline if I really find I have an interest. But that's a separate thing; for now I just want to replace a washer and fix a leaky faucet.

I've seen the same thing with ENFJs and ESFJs (Ti-Inferior). They are actually keen observers of Ti systems. But they freak out when they try to consider how a given Ti system is supposed to be used to resolve a specific problem. For example, an ENFJ of my acquaintance was astounded when I was able to retrieve an old article from my filing system. To her, that was unimaginable. She was a keen observer of Ti organizational systems on the big scale; but she confused it and mixed it up with the nuts-and-bolts Te task of actually locating one item filed a long time ago deep somewhere in that system. She didn't really see that that represents two different functions; she conflated the two. To some extent, the theoretical and the practical are at odds and have to be looked at separately.


To sum up:

In a previous essay, I talked about how Introverted functions are about building systems whereas Extraverted functions are about "experiencing" or "getting the feel" of things. Now, in this essay, I talk about how the Extraverted functions are kind of the "fireman" functions, dealing with situations on a real-time basis in the outside world, whereas the Introverted functions are more contemplative or analytical.

Also, there's a real dichotomy between Extraverted and Introverted functions like Fi and Fe. When we specialize in one, we neglect the other. That's usually not a problem if the functions are among are top functions. But if the Fi/Fe dichotomy or Ti/Te dichotomy appears in our lower functions (particularly the Inferior), we tend to be unaware of the dichotomy and try to conflate the two functions together. That creates unmanageable demands, especially in a function position where we are already weak. So we shut down or go into stress overload and implode.

YMMV. Just my own observations here.