You are probably familiar with the kind of situation in which you say something completely objective and rational, but your partner shows an emotional reaction and feels personally hurt. Or have you ever been annoyed by your wife being so utterly down to earth, when you would like to build castles in the air?

This interesting but almost incomprehensible phenomenon is well-known. Despite their individuality people "allow themselves" to be pigeonholed into certain categories.

Carl Gustav Jung explains this phenomenon by categorising people into four psychological types. According to his theory the conscious self knows four main modes of perception which express themselves differently and more or less strongly in every individual: the thinking function, the feeling function, the sensation and intuitive function. They can be defined as two antithetic pairs: thinking and feeling are rational opposites (in the sense that they evaluate and judge things). Both sensation and intuition are considered irrational functions, because they do not judge, but simply record things. Of course, not all four functions are equally strong within any one individual. One function dominates, while the other tends to be "underdeveloped". In order to become really whole, a person should attempt to develop all four modes of perception. This is an extraordinarily difficult task. Jung writes in Psychological Types:

In astrology, the twelve signs of the zodiac are attributed to the elements of air, water, earth and fire. Liz Greene considers the four elements to be the "pillars of astrology". They inform us about the predominant attitude of a person. If an individual's horoscope is dominated by fire signs, astrologers speak of a fire type. His or her predominant form of perception is "fiery", which is equivalent to the Jungian intuitive type.