If you want to understand functions, just read Jung's meaning of "extraversion" and "introversion" first. To simplifiy, it is simply orientation.
Extravert = orients around object.
Introvert = orients around subject.
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I know this, I've read chapter 10 of Phychological types.
So I guess [N=future, S=now] is fully agreed, just not the [e=pursue win, i=avoid loss] stuff.
So about the e/i stuff, let me guide you gently to my hypothesis from the conventional and maybe you see that it is the same:
==
extraversion:
When Se/Ne perceives input, it filters-out/perceives to reach the objective.
- Se sees immediately how to REAP the occasion (take it now while you have the chance, live in the moment, etc)
- Ne sees how to GROW such a future reap occasion (imagination etc, it does not see/live in the now, it sees/lives for a future better now)
==
Introversion:
When Si/Ni perceives input, it filters-out/perceives to reach the subjective
- Si sees immediatetly what to SAVE from the occasion (same stuff as Se sees, but Se reaps it (objective thing to do) and Si saves it (subjective thing to do)).
- Ni sees the way to avoid loss of the future growth potential (same stuff as Ne sees, but Ne grows it (objective thing to do) and Ni protects/saves the seed of the growth potential so the growth can happen later (subjective thing to do)).
==
again we come to this:
introverted perception= pessimistic forecast from the same input data, avoid loss (reach the subjective)
extraverted perception= optimistic forecast from the same input data, pursue win (reach the objective, THE GOAL)
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Do you know those 'over-couragous people' who are blind to losses?
Do you know those 'over-scared people' who are blind to winnings?
Of course you do, and of course you know that that is NOT a judgement thing, it is perception! And they may rationally judge in the same way, the underlying differnent perception makes the different outcome of that judgement. This perception is simply how they see the same input data differently! One sees the possible loss in the data and the other sees the possible win.
If that is perception, and we have proof all around us that these win/loss types exist, and these are obvious opposites within perception usable as good absolute ends of the spectrum, and they are not related to introverted vs extraverted, then what is left??? it must be related to introversion/extraversion, this was the hunch that lead to this hypothesis