I was thinking recently that classical elements and MBTI functions seem to tie in rather well. Not perfectly, but there seems to be common pattern between them. I stumbled upon this when I was researching elements in tarot.
The descriptions are based upon the ancient Greek philosophy of classical elements, and the quotes are from astrological elements (which are based around the former, and attempt to correlate it with personality).
Sensing (S); Perception.
Fire is considered an active element; it is weakened by water (passive), strengthened by earth (passive). Represented by an upward triangle in alchemy, and by wands (passion) in tarot.
Intuition (N); Perception.Fire personalities are believed to have good leading qualities and also tend to be enthusiastic, extroverted, rebellious, passionate, brave and valiant; however, they can also be hot-tempered, snappy, uncontrollable and angry.
Air is considered an active element; it is weakened by earth (passive), and strengthened by water (passive). Represented by an upward triangle bisected by a horizontal line in alchemy, swords (intellect) in tarot.
Feeling (F); Judgement.Air personalities tend to be kind, intellectual, communicative and social; however, they can also be selfish, superficial, vicious and very insensitive to other people's emotions.
Water is considered a passive element; it is weakened by fire (active), and strengthened by air (active). Represented by a downward triangle in alchemy, cups (emotion) in tarot.
Thinking (T); Judgement.Water personalities tend to be emotional, deep, nurturing, sympathetic, empathetic, imaginative and intuitive; however, they can also be cold, moody, jealous, sentimental, sensitive, escapistic and irrational.
Earth is considered a passive element; it is weakened by air (active), and strengthened by fire (active). Represented by a downward triangle bisected by a horizontal line in alchemy, disks (practical matters) in tarot.
----------Earth personalities tend to be calm, practical, hard-working, brave, smart, wise, stable and patient; however, they can also be stubborn, possessive, nearsighted and very harsh.
SF = fire + water
ST = fire + earth
NF = air + water
NT = air + earth
The combinations in bold are opposites. Because they are opposites, the overlaps between the elements seem to be emphasized. Both air and earth have a strong connection with logic, while fire and water have a strong connection with feeling.
The combinations in italics are complementary. Because they are complementary, the gaps between the elements seem to emphasized. There is disparity between the intellectual qualities of air and the emotional aspects of water; the creative aspects of fire and the down-to-earth qualities of earth.
Air + water (NF)/fire + earth (ST) supposedly strengthen each other, and air + earth (NT)/fire + water (SF) supposedly weaken each other. However, I don't interpret this to mean any combination is inherently weak or strong. It just means they reach balances in different ways, and interact differently.
Problems arise when you get ambiguous terms like intuition that are prescribed to fire, air, and water. Which one lays claim to intuition? I think when you break it down the differences become more clear. Intuition for each of these elements could be described as fire as creative potential, air as grasping theories, and water as intuiting emotions.