~* Wednesday, September 15, 2004 *~
I ching Structure
The I Ching symbolism is embodied in a set of 64 abstract line arrangements called hexagrams (卦 guà). These are each composed of six horizontal lines (爻 yáo); each line is either Yang (unbroken, a solid line), or Yin (broken, an open line with a gap in the centre). With six such lines stacked from bottom to top in each hexagram, there are 26 or sixty-four possible combinations and thus sixty-four hexagrams.
Each hexagram is made of two trigrams. There are 8 possible trigrams.
Each hexagram represents a state, a process, a change happening at the present moment. When an hexagram is casted, it is possible for one, many or all of the lines to be determined to be moving, ("old", or "instable") lines, i.e. their polarity is in the process of reversal and thus the meaning of the hexagram is completed and the "target" hexagram resulting from these changes is also considered.
Note that because the lines in the hexagrams are traditionally determined by biased random-number generation procedures, the 64 hexagrams are not equiprobable if generated in these ways.
There are a few formal arrangements of the trigrams and hexagrams with a traditional context. The bā gùa is a circular arrangement of the trigrams, traditionally printed on a mirror, or disk. Legend states that Fu Hsi found the bā gùa on the scales of a tortoise's back.
The King Wen sequence is considered the authoritative arrangement of the hexagrams.
Excerpt from Wikipedia