I'm going to ramble somewhat aimlessly....
When I think of MBTI & Jungian theory in a more "serious" manner, I think of cognitive processes as a psychological orientations; not behavioral patterns, not skill sets, not interests, not lifestyles, not world views, etc. At best, these are clues to a possible mindset, and many do fall neatly into a category (I fit pretty well into NF & INFP in general), but some do not, or they defy too specific details (there I do not fit as well). Thomson's answer to Eric B here is very interesting. She discusses archetypal roles vs. actual cognitive preference.
http://www.personalitypathways.com/thomson/type3-2.html
Unfortunately, in the attempt to indicate someone's mindset, MBTI has created these dichotomies, and the either/or aspect leaves some feeling alienated. Keirsey's work seems to have further muddied the divide between roles & mind sets. These seem to suggest that a type is defined by that list of observable behavior, as opposed to the intangible thought processes you detect in the form of personality. I really think it's hard to measure such processes through those means because of that.
I'm rather a fan of Jung more than any recent author, despite many creating very interesting theories, and it's probably because his definition of a Fi-dom suits me very well. Technically, I could say my MBTI type is INTP, because I test that more than half the time, but my Jungian type is definitely Fi. I don't feel the compromise an MBTI test makes me feel when I have to choose between a T & F answer.... Instead, I see a
whole mindset I can relate to, one which is not overly restrictive or which dictates what I am capable of.
However, I've also been questioning function order lately, particularly Beebe's model. I find it too rigid. I can't imagine every individual developing along such strict lines. I also don't see the functions as narrow as they appear in these models. I think if we took a broader view of the functions, then we would not need to claim a person is using Fe when making decisions that promote interpersonal harmony (or whatever). Such a decision could be made with any J function; it would be taking different roads to the same destination. I tend to see "opposing" functions very differently....I imagine it could be more natural for me, as Fi-dom, to use Ti than Te, simply because the orientation is preferred. Te seems the more opposed function to Fi, and irks me far more when I encounter it in others. A model which took that angle might suit me better.
I do appreciate that MBTI focuses on defining personality based on the dom & aux functions - the primary ways of judging & perceiving. Outside of what I think is not a great system to indicate type, this concept makes sense to me. Your top two functions are what color your personality, and we see this everyday in people. Once you're aware of types, you can spot them rather easily, and this is enough evidence to convince me the labels are largely accurate in explaining a major aspect of personality.
However, when you get into tertiary and inferior functions, it just seems like a lot of guesswork & speculation at best. It seems very questionable to be typing people based on them also; what forms the "visible" personality will be the main two functions, IMO. Lately, when people speak of their tertiary this & that, I cringe because it seems so unlikely that it's really a major force in their personality. It also begins to associate skills with functions. Instead of considering that maybe their F mindset actually made a logical deduction, they have to delegate it to their tert or inferior T, as if functions are gears you shift in & out of instead of a whole frame of mind. I'll paraphrase Peacebaby (I think it was her), who said once that you can't unbake a cake, and sometimes function order seems to try to do that. You can "taste" a person and determine their main type, chocolate or strawberry
, but you can't really know the lesser components based on the final product alone. I feel clear I use F & N functions, and my dominant is Fi, but beyond that it's really a grab bag as to how the other functions play out in my mindset.
I personally don't see Si as my tertiary in the way they want to define it; I can start ascribing behaviors to functions, but that's really a misuse of the theory.
When I think of MBTI in a more playful sense, then I am comfortable using phrases like "Fi-Si loop", which I just see as shorthand for a common mental rut INFPs get stuck in. How that mental rut actually relates to the functions is not the point; it's just a phrase unique to a community that expresses in terms of Jungian theory
. What I mean to say is, I'm no MBTI gestapo who has a problem with that type of casual discussion, which tends to serve its own purpose.