Bagua


The bagua is a set of symbols from China intended to illustrate the nature of reality as comprising mutually opposing forces reinforcing one another. Bagua is a group of trigrams—composed of three lines, each either "broken" or "unbroken", which represent yin and yang, respectively. Each line having two possible states allows for a total of 23 = 8 trigrams, whose early enumeration and characterization in China has had an effect on the history of Chinese philosophy and cosmology.
The trigrams are related to the divination practice as described within the I Ching and practiced as part of the Shang and Zhou state religion, as well as with the concepts of taiji and the five elements within traditional Chinese metaphysics. The trigrams have correspondences in astronomy, divination, meditation, astrology, geography, geomancy, anatomy, decorative arts, the family, martial arts, Chinese medicine and elsewhere.
The bagua can appear singly or in combination, and is commonly encountered in two different arrangements: the Primordial, "Earlier Heaven", or "Fuxi" bagua, which is so named according the legend of Fuxi being the first primordial being to identify the eight trigrams; and the Manifested, "Later Heaven", or "King Wen" bagua, which arose recorded Chinese history.
In the I Ching, two trigrams are stacked together to create a six-line figure known as a hexagram. There are 64 possible permutations. The 64 hexagrams and their descriptions make up the book. The trigram symbolism can be used to interpret the hexagram figure and text. An example from Hexagram 19 commentary is "The earth above the lake: The image of Approach. Thus the superior man is inexhaustible in his will to teach, and without limits in his tolerance and protection of the people." The trigrams have been used to organize Yijing charts as seen below.

Trigrams

There are eight possible combinations to render the various trigrams:
Trigram figurePossible binary valuePossible decimal sequential numberNameTranslation: WilhelmImage in nature PhaseLater Heaven's Direction Later Heaven's Equinox or SolsticeEarlier Heaven's DirectionEarlier Heaven's Equinox or SolsticeFamily relationship Body part Attribute Stage/ state Animal Obtained Images
11117c=乾
the Creative, ' force'heaven, sky
metalnorthwestsouthSummer Solsticefatherheadstrong, persistingcreative
horse
三連
three lines
21106
the Joyous, 'open 'lake, marsh
metalwestFall Equinoxsoutheastthird daughtermouthpleasuretranquil
sheep, goat
上缺
flawed above
31015
the Clinging, 'radiance'fire, glow
firesouthSummer SolsticeeastSpring Equinoxsecond daughtereyelight-giving, humane "dependence"clinging, clarity, adaptable
pheasant
中虛
hollow middle
41004
the Arousing, 'shake'thunder
woodeastSpring Equinoxnortheastfirst sonfootinciting movementinitiative
dragon
仰盂
face-up jar
50113
the Gentle, 'ground'wind, air
woodsoutheastsouthwestfirst daughterthighpenetratinggentle entrance
fowl
下斷
broken below
60102
the Abyssal, 'gorge'water
waternorthWinter SolsticewestFall Equinoxsecond soneardangerousin-motion
pig
中滿
full middle
70011
Keeping Still, boundmountain
earthnortheastnorthwestthird sonhandresting, stand-stillcompletion
dog
覆碗
face-down bowl
80000
the Receptive, fieldground, earth
earthsouthwestnorthWinter Solsticemotherbellydevoted, yieldingreceptive
cow
六斷
six fragments

Relation to other principles

The Scripture of Changes 易經 listed two sources for the eight trigrams. Its chapter explains the first source thus:

Tài Jí (太極) Great Axis

Taiji is the encapsulation of all the universe, space and time.
It is derived from Wújí 無極 the formless, dimensionless, limitless, unbounded, infinite void.
When the formless void began to stir and move, Taiji came into being.

Liǎng Yí (兩儀) Dual Powers

The beginning of the universe begot the twin forces:
  • ⚋ yīn dark, original, central, passive
  • ⚊ yáng bright, extreme, furthest, active

    Sì Xiàng (四像) Four Aspects

The twin powers produce four aspects named:
  • ⚌ great yang 太陽 tàiyáng
  • ⚎ lesser yang 少陽 shǎoyáng
  • ⚍ lesser yin 少陰 shǎoyīn
  • ⚏ great yin 太陰 tàiyīn
The four aspects are the differing levels of energy in world. Primarily they are associated with the solar terms, the two solstices and the two equinoxes. Being aspects they are also associated with the four main compass directions. Each direction is associated with a level of solar energy, and a mythological animal.
  • ⚌ great yang 太陽 tàiyáng, Summer Solstice, South, Red Bird
  • ⚎ lesser yang 少陽 shǎoyáng, Spring Equinox, East, Blue Dragon
  • ⚍ lesser yin 少陰 shǎoyīn, Fall Equinox, West, White Tiger
  • ⚏ great yin 太陰 tàiyīn, Winter Solstice, North, Black Tortoise

    Bā Guà (八卦) Eight Passages

The four phenomena act through the eight gates :
  • ☰ Heaven p=Qián, warming
  • ☳ Thunder p=Zhèn, storming
  • ☵ Water p=Kǎn, pooling
  • ☶ Mountain p=Gèn, jutting
  • ☴ Wind p=Xùn, dispersing
  • ☲ Fire p=Lí, dancing
  • ☱ Lake p=Duì, engulfing
  • ☷ Earth p=Kūn, resting
Another chapter, p=Shuō Guà, characterizes the relationship of the trigrams as being:
  • p=Qián ☰ Heaven, Father
  • p=Kūn ☷ Earth, Mother
who have three sons:
  • p=Zhèn ☳ Thunder, 1st Son
  • p=Kǎn, ☵ Water, 2nd Son
  • p=Gèn ☶ Mountain, 3rd Son
and have three daughters:
  • p=Xùn ☴ Wind, 1st Daughter
  • p=Lí ☲ Fire, 2nd Daughter
  • p=Duì ☱ Lake, 3rd Daughter
The son trigrams all have a single ⚊ yáng line in their formation. The Yang trigrams correspond to odd numbers 1, 3, 5, 7.
The daughter trigrams all have a single ⚋ yīn line in their formation. The Yin trigrams correspond to even numbers 0, 2, 4, 6.
Their ordering is from bottom line, mid line, top line.

Wǔxíng (五行) Five Phases

The trigrams are related to the five phases of the Wuxing. The phases are: Water, Wood, Fire, Earth and Metal.
The major qualities associated with the 5 phases are:
  • Water - Receding
  • Fire - Bursting
  • Earth - Resting
  • Wood - Growing
  • Metal - Contracting
These qualities are associated with the seasons.
  • Water is associated with mid winter, the time of lowest energy.
  • Fire is associated with mid summer, the time of highest energy.
  • Earth is the pivot or balanced energy, either given as late summer, or as a brief transitional period between the seasons, where they are neither obviously one quality or the next.
  • Wood is associated with the spring time, burst with life and increasing sunshine.
  • Metal with the fall, life is slowing down, the days are shortening, and both men and creatures are taking precaution by storing food, and preparing for winter.
Typically the trigram-to-phase correspondences are given as follows:
  • The phase of Water 水 only corresponds with the trigram of the Deep p=Kǎn.
  • The phase of Fire 火 only corresponds with the trigram of Flame p=Lí.
  • The phase of Earth or Soil 土 corresponds with the trigrams of Earth p=Kūn and Mountain p=Gèn.
  • The phase of Wood 木 corresponds with the trigrams of Wind p=Xùn and Thunder p=Zhèn.
  • The phase of Metal or Gold 金 corresponds with the trigrams of Heaven p=Qián and Lake p=Duì.
Notably, more than just their seasonal correspondence, the elements have interactions with each other and relationships of promoting and subverting other elements, as well as reversals where there is insufficiency in one element, resulting in an unbalanced relationship giving unexpected results where it should normally promote or subvert another element, but gives the opposite effect.
The wuxing and its promoting/subverting relationship system is also used as a frame work for understanding the relationships in spacial features in feng shui as well as the relationships between the organ systems in traditional Chinese medicine.

''Liùshísì Guà'' (六十四卦) Sixty-Four Hexagrams

Eight trigrams stacked atop another eight trigrams give sixty-four variations of hexagrams, with the dominant quality above, and the secondary quality below. These sixty four hexagrams make up the main body of the Yijing oracle used for divination. The Yijing itself gives a pithy explanation for each hexagram.
The ways can be thought of as eight main expectations, and each variation is an outcome either typical, inverted; promoted, subverted; nurtured, neglected; surprised or disappointed; depending on circumstance. The sixty-four hexagrams give many possibility for how an endeavor may turn out.
Diviners consulting the Yijing oracle use a variety of methods to elicit a response from the oracle, such as throwing yarrow stalks, tossing coins, pulling cards from a deck, or consulting exterior signs, such as examining the shapes of sacrificed animal entrails, examining the cracking patterns of bones tossed into a fire, observing the flight path of startled birds, etc.