I've been looking at Socionics, MBTI, and Jungian theory for a long time now. Ultimately, I'm unable to determine my type with any degree of accuracy in any particular system, because the meanings of the functions seem so esoteric. This weakness can be found in all of these systems relying upon Jung's definitions, which were inherently vague (but still interesting). I can't really see how to differentiate one function from another, because any action you take could be due to the motivation of any function. For instance, saying "Hello." to someone could be due to several motivations. It could be Extraverted Feeling, desiring to connect to others and express one's interest and concern for the other person's emotional state. It might be Introverted Sensing, displaying what it believes is the proper and accepted "form" for social interactions. It could be Introverted Thinking, having developed or recognized a system for social interaction. It could be Extraverted Intuition, wishing to see what new potentialities arise from the greeting. It could be Extraverted Thinking, viewing the greeting as a step in working towards a specific goal. It could be Introverted Feeling, believing that this interaction will result in an emotional intensity for them. I could continue, but I think you probably see the point. How can anyone actually know their type, if actions aren't necessarily caused by any particular function, and one cannot always be certain of what one's primary motivation was in the first place, whether you had more than one motivation, or whether this particular set of motivations is even valid or complete? This seems to be quite a mess. How can anyone really understand this?