The seeming elegance and symmetry of the table of functions prompted me to use a technical side of my brain to ask a what if question about the other possible Jungian functions.I used combinatorics(math) to calculate all possibilities of arranging letters F,S,T,N as well as adding an alternating i/e flavor. There are two options for the flavors (once we know the i/e flavor of the first function, the rest are determined because they alternate).For illustration, I enumerated one quarter of all possibilities (only those starting with an F but you can keep going yourself if you like). The original 16 types are listed below that. As you can see, there are many gaps - only 4 of 12 used here and 16 of 48 used overall. So, exactly 1/3 utilization. The mathematical elegance is a tease, makes me think that this theory is based on something real, but is it? Could it be an elegant accident or an elaborate hoax instead? Why are some combinations not possible?E/I 1   2   3   4   functions   MBTI?e   F   N   S   T   FeNiSeTi    ENFJi   F   N   S   T   FiNeSiTe    INFPe   F   N   T   S   FeNiTeSi    ?i   F   N   T   S   FiNeTiSe    ?e   F   S   N   T   FeSiNeTi    ESFJi   F   S   N   T   FiSeNiTe    ISFPe   F   S   T   N   FeSiTeNi    ?i   F   S   T   N   FiSeTiNe    ?e   F   T   N   S   FeTiNeSi    ?i   F   T   N   S   FiTeNiSe    ?e   F   T   S   N   FeTiSeNi    ?i   F   T   S   N   FiTeSiNe    ?.................................MBTI    1   2   3   4INTP    Ti  Ne  Si  FeISTP    Ti  Se  Ni  FeENTP    Ne  Ti  Fe  SiENFP    Ne  Fi  Te  SiISFP    Fi  Se  Ni  TeINFP    Fi  Ne  Si  TeINTJ    Ni  Te  Fi  SeINFJ    Ni  Fe  Ti  SeESTJ    Te  Si  Ne  FiENTJ    Te  Ni  Se  FiESFJ    Fe  Si  Ne  TiENFJ    Fe  Ni  Se  TiISTJ    Si  Te  Fi  NeISFJ    Si  Fe  Ti  NeESTP    Se  Ti  Fe  NiESFP    Se  Fi  Te  Ni
Why only 16 Jungian types? Combinatorially it should be 2 * 4! = 48
personality;jung