Tertiary Temptation: The temptation, when we feel pressure from our Inferior Function, to explain our problems to ourselves in terms of an attitude opposite to our Secondary Function. This supports the self-understanding of our Dominant Function in Extraverted or Introverted terms, whichever we are most accustomed to. This cognitive move doesn't lead us to address the real problems, which would require a more genuine change in perspective; it does, however, restore an inner sense of harmony.
When introverts run into a situation that their Dominant Function can't handle, they need to adapt by negotiating, going along with the limitations of low-bandwidth social interaction, or otherwise doing something that does not involve total control or understanding of the situation. The Tertiary Function provides justification for maintaining an Introverted approach directly opposite to the worldly expansiveness that the person is ready for.
Tertiary Ti (IxFJ)
: "I can't possibly go along with this, because it makes no sense. It's filled with internal contradictions. It's crude and not true to the real principles of how this works. It's trying to shove an inappropriately a priori conceptual structure onto the reality. I will have to go by feel, and where it leads I can't know until I get there. I've got to trust this groove regardless of people's arbitrary expectations." The Secondary Function (Fe) would say: "You've reached the limits of what you can do alone. You can make others feel important by telling them your needs and asking for their help, and yielding some genuine control to them. See who you can find common cause with."
Tertiary Fi (IxTJ)
: "I can't possibly go along with this, because it would mar my soul. It's not 'me'. I am a good person, and in order to maintain my integrity, I need to steer clear of this. This is the responsibility of those other people: it emerges from their souls, not mine, so it's their problem." The Secondary Function (Te) would say: "Do something. Take responsibility even if no one gave it to you, and go after some tangible gain right now, within the limits of the situation and your current understanding. That will improve your position, after which you can re-assess and plot a new course."