The four Elements of astrology refer to four basic temperaments:
They are also called Triplicities. These vibrational patterns have a connection to every
third sign of the zodiac, which form harmonious trine aspects to each
Webster's dictionary defines the word temperament
as a "combination of mental, physical, and emotional
traits of a person; the natural predisposition".
And like many other human traits, the expresion of the Elements can range from mild to extreme.