I think I get it. We can't prove that there's actually a "Ti mechanism" that processes after a "Ne mechanism". We could sum up the critics by saying "the map is not the territory". Functions are abstractions. Etc etc
But do we deny that this sort of a definitions list: TPs, FPs, TJs, FJs creates a pretty compelling arguement for judging function descriptions having some legitamacy?
TJs tend to plan things and use structured methodical ahead of time thinking throughout their lives.
TPs tend to find the holistic logic of a situation ("let me break it down for you") and leverage this information as they see fit.
FJs tend to plan things and use structured methodical ahead of time thinking according to how "the audience" is supposed to react.
FPs tend to find the holistic "how does this make ME feel" logic of a situation and leverage this information as they see fit.
They aren't function definitions. Theres no functions voodoo. They are completely pulled from the obsevation of overlapping two of the four dichotomies. ...and yet, they stand in for function definitions pretty **** well. What say you function doubters?