The significance of P and J.
I learnt this on TC a while back, and it made so much sense to me. This is too ingenious for me to explain, so I'm paraphrasing (and quoting) the incredible ENTP who laid it out so clearly :P
Supposedly the P/J is the most important letter in typology because it dictates how the other "cognitive functions" will be used. Each person functions with a combination of 2 cognitive functions out of the 4 possible.
1) Perceiving function with either S or N, because it takes in information.
2) Judging function with either T or F, because it makes decisions with that information.
Each person has one function that is extroverted, directed outwardly - handling the outward situation, ideas, things apart from the self, and one function that is introverted, directed inwardly - creating inner values and perspective, the self itself.
"Your two primary functions are represented