In Chinese "Tài 太" means the highest or supreme, as in describing the highest heaven or the supreme ruler. "Jí 极" means the last or the ultimate. The word "Tàijí太极" first appeared in The Book of Changes, which was written more than 3,000 years ago, in a reference to the most primitive state of the universe, the origin of all changes, or the highest realm of existence.
The Book of Changes (Yìjīng 易经) is composed of two parts, the Text (Jīng 经) and Commentaries (Zhuàn (传). The Text deals mainly with divination and an integrated system of trigrams or hexagrams (guà卦). As symbols of divination, the eight trigrams are formed in various ways to tell fortunes according to interpretations of the lines of the trigrams. Legend has it that the classic Text was written by the King Wen of the Zhou Dynasty (11 century- 256 BC). The Commentaries include an interpretation or discussion of the Text, composed of philosophical essays by many different people that express their world outlook based on the theory of yin and yang. In "The Great Interpretation" essay in the Commentaries section of The Book of Changes, Taiji was first mentioned as follows:
"Yì (易) contains Tàijí(太极) which gave birth to the two basic elements; the two basic elements gave birth to the four symbolic figures; the four symbolic figures then gave birth to the eight elementary trigrams (bāguà八卦) that can predict fortune and misfortune, which enables great accomplishment."
Here Taiji refers to the origin of changes, the most primitive state from which everything evolves. It is the highest state of existence. Throughout the ages, Chinese scholars have offered different philosophical interpretations of the world based on the Taiji yin-yang theory. For example:
"Before Heaven and Earth were divided, the primal fluid--primary elements that form Heaven and Earth--were combined into one. That is the beginning of the great Unity of Tai or the great oneness of Tai."
-- Kong Yingda of the Tang Dynasty (618-907)
"Taiji was the primeval chaotic and primitive state of the universe before Heaven and Earth were formed."
--Wang Tingxiang of the Ming Dynasty (1368-1644)
