So I'm reading the MBTI manual 3rd edition for the first time and on page 30, I noticed that it supposes that each type has either an introverted or extroverted direction for their first function, and then every other function is the opposite of that. That's not the logic they use to justify it, however it is the effect. So for example they used ESTJ and said it has a dominant extroverted thinking function, and then introverted sensing, N and feeling. This was published in 98'. At what point did MBTI begin doing it the way of every other function was opposite in direction to the previous one? Or did they never argue that and its become a popular online forum sort of thing?