Carl Jung developed psychological types based on the four functions (Feeling, Thinking, iNtuition and Sensing) and the two attitudes (Extraversion and Introversion). (There is, in my experience, a good deal of confusion, especially among those without some grounding in psychological type, about the nature of these functions and attitudes. The words don't necessarily mean what we expect them to mean, and caution should be used in applying common usage to these terms if this system is to be of value in the understanding of basic temperaments.)
In this system there are eight basic types, each designated by its dominant (defining, controlling, pre-eminent) function:
|Symbol||Jungian Type||Myers-Briggs Types|
|Fe||Extraverted Feeling||ESFJ ENFJ|
|Fi||Introverted Feeling||ISFP INFP|
|Ne||Extraverted Intuition||ENFP ENTP|
|Ni||Introverted Intuition||INFJ INTJ|
|Se||Extraverted Sensing||ESFP ESTP|
|Si||Introverted Sensing||ISFJ ISTJ|
|Te||Extraverted Thinking||ESTJ ENTJ|
|Ti||Introverted Thinking||ISTP INTP|
Of the four functions, two (Feeling and Thinking) are the rational, or deciding, functions. The other two (Sensing and iNtuition) are the irrational (non-conclusive/perceiving) functions. If an individual has a dominant rational function, one of the irrational functions is always auxiliary. Likewise, dominant N (irrational) would have an F or T (rational) function. Third and fourth functions are mirror-images of the first and second. For example, if Sensing is first and Thinking is secondary, Feeling (the opposite of Thinking) must be tertiary, and iNtuition (Sensing's opposite) would be fourth.
There are two schools of thought concerning the attitude, or direction of energy flow, of each function within a given type. Some believe that if the dominant function is Introverted, the other three will be Extraverted; likewise, an Extravert's non-dominant functions are all Introverted. Others think that the attitude alternates from first to fourth position as I/E/I/E for Introverts and E/I/E/I for Extraverts. The functional analyses in our profiles follow the latter alternating pattern.
In summary, the sixteen types in four-function terminology are: