... Ti the opposite of Fe, nor Te the opposite of Fi and nor Ni the opposite of Se.
Why would the opposite of a perceiving function still be a perceiving function? And why would the opposite of a judging function still be a judging function?
An opposite by definition would be one who has nothing in common (with the other), aka no shared ground, all differences. Hence, Ne cannot be opposite to Si because they have a shared ground: perceiving.
Therefore, only judging functions, like Ti or Fi, have the potential to be Ne's true opposite.
But which one?
To find out, we need to look at the functions themselves. If we take a look at thinking and feeling we see that feeling is far more dynamic/natural (think spider web) than thinking, which is more lineair/fixed (cause->effect). To the thinker, only one answer can be the correct one (1+1=2, ONLY 2), whereas the feeler does not see it this way. T thinks in black-white, whereas F thinks in grey, simplistically speaking.
This means that N/intuition (also about possibilities) has more in common than F/feeling than it has with T/thinking. So to make a big leap here based on all I know about MBTI/Jung I would say feeling is the judging counterpart of intuition, whereas thinking is the judging counterpart of sensing.
Taking this insight to its rational conclusion we would have T/thinking being the opposite of N/intuition, and F/feeling being the opposite of S/sensing. There is a reason why ST's often can't stand intuitives, because N messes up their inner T framework by building bridges between seemingly separate concepts. Sure, a T may not get the emotional framework of F's, but F's sure do not question or try to alter their logical framework like N's do.
This means that the real opposites are as follows:
Se <-----> Fi
Si <------> Fe
Ne <-----> Ti
Ni <------> Te
To make this easier to understand, I would invent a new dimension besides extraversion/introversion and judging/perceiving. To pick a name I would call this the spiritual/material or flying/grounded dimension, where spiritual/flying would depict N or F and material/grounded would depict S or T. (This is the reason why STJ's are often seen as "fixed" or "close-minded", because they have no "flying" functions in their conscious psyche, coupled with their J. Or on the other hand, why NFP's are so "out there", unrealistic and/or impractical..)
An extraverted flying judger would then be codename for Fe, or an introverted grounded perceiver would be codename for an Si dominant.
Ofcourse, if my hypothesis is true then this poses a threat to the MBTI typing system. Yet, so what... The truth is what matters, not the established model/system. If it can't adapt to new ideas/perceptions then it's more dogma than anything else...
However, the model can easily be adapted by switching the inferior from its old opposite to its new opposite, and then adding in the remaining pieces of the puzzle, like this:
ESTP: now (Se -> Ti -> Fe -> Ni) becomes (Se -> Te -> Ni -> Fi) where Se and Te will be the conscious/ego functions and Ni and Fi will be the unconscious/shadow functions with Fi the inferior. As you can see (surprise myself), in this case the auxiliary had to be of the same E/I attitude otherwise the ESTP puzzle cannot be solved. However, don't take this fact as disproof of my theory, since Carl Jung himself never said that the auxiliary must have an opposite E/I attitude than the dominant function.
Ofcourse if the functions of your new type do not match with yourself at all then try considering a different type in the new model. I'll be good samaritan and list the new types in advance:
ST's or pragmatists:
ESTj: Te -> Se -> Fi -> Ni (shadow: INFp)
ESTp: Se -> Te -> Ni -> Fi (shadow: INFj)
ISTj: Ti -> Si -> Fe -> Ne (shadow: ENFp)
ISTp: Si -> Ti -> Ne -> Fe (shadow: ENFj)
NF's or idealists:
ENFj: Fe -> Ne -> Ti -> Si (shadow: ISTp)
ENFp: Ne -> Fe -> Si -> Ti (shadow: ISTj)
INFj: Fi -> Ni -> Te -> Se (shadow: ESTp)
INFp: Ni -> Fi -> Se -> Te (shadow: ESTj)
TF's or rationals:
eTFJ: Te -> Fi -> Se -> Ni (shadow: iNSP)
iTFJ: Ti -> Fe -> Si -> Ne (shadow: eNSP)
eFTJ: Fe -> Ti -> Ne -> Si (shadow: iSNP)
iFTJ: Fi -> Te -> Ni -> Se (shadow: eSNP)
SN's or freebirds:
eSNP: Se -> Ni -> Te -> Fi (shadow: iFTJ)
iSNP: Si -> Ne -> Ti -> Fe (shadow: eFTJ)
eNSP: Ne -> Si -> Fe -> Ti (shadow: iTFJ)
iNSP: Ni -> Se -> Fi -> Te (shadow: eTFJ)
Due to incompatibility with dominant/inferior functions, the NT temperament had to disappear, together with the SF's. These got replaced by the TF's and SN's.
Thoughts? Can you resonate with a new type? (Personally, I can see myself as an eNSP.)