I've been trying to figure out the correct derivation for some time.
We have:
Attitudes: I/E
Functions: N/S, T/F
Rationality: J/P
How did the final element structure evolve? I have some thoughts depicted in microsoft paint:
Idea 1
Idea 2
I prefer the former, partially because it might include the latter as a sub-system.
Alot of this topic may be muddled with conceptual distinctions that are irrelevant.