The oracle of a hexagram exhibits itself in the form of the phenomenon which is primarily derived from the images or the characteristics of the paired trigrams. Following is an overview of the eight trigrams, mainly quoted from Shuo Gua Zhuan (Confucian commentary on trigrams).
Fu Xi Bagua (also called: earlier or pre-heaven Bagua), i.e. the inborn eight-trigram diagram
circulating. The thunder (Zhen) and wind (Xun) approach each other; they can travel far together and with prestige, and all life is aroused. Though water (Kan) and fire (Li) tend to subdue each other; however water flows downward while flames blaze upwards, and they remain parallel; therefore they won’t defy each other; in their balance all life benefits and prospers. Therefore it is said that the Fu Xi Bagua mainly presents the origination and essence of the eight trigrams.
Each group of dots on the river map represents a number; the combination of the central 5 with the surrounding groups of dots produces the four basic dualities. For example, the central 5 plus 4 on its right equals to 9, which is the number of the old masculine. The remaining three dualities are similarly formed. 8 on the left is the young feminine, 7 at the top is the young masculine, and 6 at the bottom is the old feminine. Afterwards the eight trigrams are created by placing one additional masculine or feminine on top of each of these four dualities.
Wen Wang (or King Wen) Bagua (also called: later or post- heaven Bagua), i.e. the acquired eight-trigram diagram
The Wen Wang Bagua mainly relates to the application of the eight trigrams. Its diagram starts with Zhen (to move, the thunder), unfolds clockwise, and ends at Gen (keeping still, the mountain).
All creatures originate from Zhen (to move, the thunder), like the plant aroused by the spring thunder starting to sprout. It is located in the east where the sun (i.e. the masculine power) rises; therefore it is taken for the spring equinox.
All creatures grow and act in unison at Xun (to enter, the wind), like blooming sunflowers being bent widely over grasslands by the wind. It is in the southeast and is also taken for the beginning of summer.
Li (clinging, fire) provides brightness and makes all creatures be visible and able to see one another. It is a trigram of the south, as the south, according to Chinese geography, is a place with longer daylight. It is also taken for the summer solstice, where all creatures are prospering and form their shapes.
Kun (submissiveness, earth) is earth, whereby all creatures are nourished becoming strong, like plants growing mature and bearing fruits; therefore it is said: all being served by Kun. It is located in the southeast and is taken for the beginning of autumn.
Dui (joy, the marsh) is the autumnal equinox, where all creatures feel joyful while celebrating the fruitful harvest; therefore it is said: Dui is signified as joy. It is in the west.
Battling at Qian (perseverance, heaven) means masculinity and femininity approaching each other at Qian. It is a trigram of the northwest and is taken for the beginning of winter as masculinity is overpowered by femininity and starts declining.
Kan (the abyss, water) is water. In comparison with Li, fire and the south, water is cold and a trigram of the north. It is also a trigram of toil or fatigue as all life must work hard in the cold north, and they return (home) to where all creatures belong after almost one year working and getting tired. Therefore it is said: toil or fatigue at Kan. It is taken for the winter solstice.
Gen (keeping still, the mountain) is a trigram of the northeast. All creatures have accomplished their tasks and (are going to) have a new beginning; therefore Gen is seen as accomplishment. It is also taken for the beginning of spring.
The genders of the eight trigrams
According to Xi Ci Zhuan (the commentary on the text tagging), odd numbers represent the masculine, and even numbers represent the feminine.
The gender of a trigram is determined by the number of its line strokes, i.e. the total strokes of its solid and broken lines. The trigram with even strokes is feminine; therefore Kun (submissiveness, earth), Dui (joy, the marsh), Xun (to enter, the wind) and Li (clinging, fire) are the feminine trigrams. The trigram with odd strokes is masculine; therefore Qian (perseverance, heaven), Kan (the abyss, water), Gen (keeping still, the mountain) and Zhen (to move, the thunder) are the masculine trigrams. The masculine trigram tends to be rigid, strong and firm, while the feminine trigram tends to be soft, weak and tender.
The roles of the eight trigrams in a household
Qian (perseverance, heaven) denotes the father as Heaven originates all life. Kun (submissiveness, earth) denotes the mother as the earth nourishes all life.
Zhen (to move, the thunder) denotes the eldest son. A masculine line of Qian enters Kun and occupies its bottom position as the first mating. It is a masculine trigram. Kan (the abyss, water) denotes the middle son. A masculine line enters Kun and occupies its middle position as the 2nd mating, and it is a masculine trigram as well. Gen (keeping still, the mountain) denotes the youngest son. A masculine line enters Kun and occupies its top position. This signifies the 3rd mating and it is a masculine trigram.
Xun (to enter, the wind) denotes the eldest daughter. A feminine line of Kun enters Qian and occupies its bottom position as the first mating, and it is a feminine trigram. Li (clinging, fire) denotes the middle daughter and Dui (joy, the marsh), the youngest daughter; they are created in the same manner as described above.
The human body represented by the eight trigrams
Qian (perseverance, heaven) denotes the head as the heavens at the top of the world is like the head on the human body. Qian is also designated as the leader of trigrams.
Kun (submissiveness, earth) denotes the abdomen as the abdomen contains foods (i.e. those created by the world) like the earth accommodating the whole of creation.
Zhen (to move, the thunder) denotes the foot as Zhen is designated to move.
Xun (to enter, the wind) denotes the thigh as its feminine line at the bottom is composed of two line strokes, looking like two thighs on the human body.
Kan (the abyss, water) denotes the ears as its two feminine lines look like the ears on the human head.
Li (clinging, fire) denotes the eyes. Li represents fire which makes things visible. The two line strokes in the middle look like the eyes on the human face.
Gen (keeping still, the mountain) denotes the hand as it looks like a hand grasping downward.
Dui (joy, the marsh) denotes the mouth as Dui also signifies to speak, and its feminine line at the top looks like the lips.
The animals represented by the eight trigrams
Qian (perseverance, heaven) denotes the horse as the stamina of the horse galloping is like the perseverance of the heavens in operating.
Kun (submissiveness, earth) denotes the cattle as cattle carries heavy load like the earth bearing the whole of creation.
Zhen (to move, the thunder) denotes the dragon as the flying dragon roars in the sky like Zhen thundering.
Xun (to enter, the wind) denotes the chicken. The feminine line is seen as the wing. The chicken can't fly as Xun's feminine line stays at the bottom.
Kan (the abyss, water) denotes the pig. The pig is fat and Kan has the tender (feminine) line on either side.
Li (clinging, fire) denotes the pheasant. The pheasant is as brilliant as Li.
Gen (keeping still, the mountain) denotes the dog as the dog stops the trespasser like the mountain stopping people from passing.
Dui (joy, the marsh) denotes the goat as the goat is stubborn but with a docile countenance like Dui hiding its masculine rigidity behind the feminine tenderness.
The colours of the eight trigrams
According to Shuo Gua Zhuan, Qian (perseverance, heaven) is bright red (i.e. the colour of celebration. The brightness of the masculine is symbolic of happiness. When all the lines are masculine, i.e. happiness extends to all, it signifies celebration), while Kun (submissiveness, earth) is black (as Kun is composed wholly of the shaded feminine lines); Kan (the abyss, water) is red (as Kan is a trigram of blood) and Xun (to enter, the wind) is white (as the wind blows away all colours); Zhen (to move, the thunder) is the blended colour of dark blue and yellow (as Zhen is the eldest son, and dark blue and yellow are the colours of heaven and earth, i.e. the parents, respectively).
Also according to Chinese tradition, each direction is given a colour: the east is cyan; the south is red; the west is white, and the north is black. The centre is given the colour yellow. Therefore, Zhen in the east is cyan; Li in the south is red: Dui in the west is white; Kan in the north is black, and earth in the middle is yellow.
Miscellaneous objects represented by the eight trigrams
The image of a trigram is usually created according to its characteristics associated with an object. Each trigram possesses numerous images and the image varies with time and place, people and particular event. The following are some examples.
Qian has the characteristic of creativeness and perseverance; it represents heaven. It also denotes roundness (as the heavens revolve ceaselessly), the king (as his prestige is like Heaven), jade and metal (or gold, as they are as rigid and brilliant as masculine Qian), cold (as Qian is in the northwest, a place of less sunshine), ice (as Qian is cold and rigid), a good horse (as it gallops in a persevering way), an old horse (as Qian denotes father), a thin horse (as the solid line is taken for the lean), a belligerent horse (as it is rigid and persevering like Qian), and fruits on a tree (like stars in the heavens).
Kun has the characteristic of submissiveness and receptiveness; it represents earth. It also denotes cloth (which wraps things like the earth accommodating all creatures), a cooking vessel (like the earth nourishing all life), a calf and a cow (both are as docile as Kun), a big cart (like the earth bearing the load of the world), a quality of culture (demonstrated through the decent behaviour of feminine Kun), a multitude (of people nourished by the earth), and the handle (like the earth carrying the whole of creation). Additionally it symbolises skimpiness (as Kun is composed of the feminine lines, i.e. the void lines), and even distribution (as the earth impartially nourishes all life).
Zhen has the characteristic of move and represents the thunder. It also denotes the dragon (as the dragon soars in the sky like the thunder), an avenue (Zhen is a trigram of the spring equinox which is the avenue for life), the green young bamboo, and the spreading reed (which grows quickly like the thunder). Referring to the horse, it denotes the white rear left leg, and the white forehead (which can be seen easily even when the horse is galloping); it is associated with a horse good at neighing (like the thunder booming repeatedly), and a horse lifting its front legs (as Zhen is very active). Referring to the crop, it means reverse growth (i.e. a sprout growing downward into earth, as its feminine lines remain still at the top while its masculine line tends to move beneath). Additionally it is signified as: to apply (substance such as paint) all over (like the thunder reaching everywhere), and changing decision swiftly and testily (like the unpredictable thunder). When Zhen behaves differently from its normal becoming perseverant, it symbolises lushness and vividness (as plants can continue growing flourishingly if Zhen perseveres in carrying on its job as the spring equinox, even though it is capricious).
Xun has the characteristic of entry and prostration (in a modest and obedient manner); it represents the wind. It also denotes wood (the masculine above tend to move and the feminine below remains still, like a plant growing upward with its root firmly in earth) and the marking cord (used to carpenter straight woodworks which are associated with the plants growing in unison at Xun). Additionally it is signified as: craftsmanship (which transforms wood into woodworks), a long distance (as the wind can go far), height (as the wind can rise to the sky), advancing and receding (like the wind travelling back and forth), indecision (like the wind moving without a fixed direction), and odour (brought by the wind). Referring to humans, it denotes the sparse hair (like the leaves remaining on a tree after a gale), a broad forehead (because of the sparse hair), and the white of the eye very visible (i.e. a disdainful look, like the bright masculine on the top of the dark feminine); it also means to earn a profit three times the average (as Qian denotes gold and the feminine line makes it become an entry, i.e. income). When Xun behaves differently from its normal, it is (no longer a gentle breeze but) a trigram of uneasiness (signifying that it becomes a hurricane, like the violent thunder of Zhen, its changing hexagram).
Kan has the characteristic of the abyss and represents water. It symbolises peril (as the abyss is perilous), sincerity & trust (as its solid line in the middle is seen as a reliable heart), aspiration (which originates from the heart), hiding in a prostrate way (like its masculine line lying between the shaded feminine lines), straightening and bending (wood over fire, like water flowing either straight or round), It also denotes the river, the ditch, the bow, and the wheel (which forms after bending). Referring to humans, it is signified as: to worry about (the perilous abyss), the illness of the heart (as Kan is the heart and worry), the earache (as Kan denotes the ears and it is a trigram of toil or fatigue), a trigram of blood (which circulates in the human body like water on the earth), red (like the blood). Referring to the horse, it denotes the beautiful spine (like its solid line in the middle), an impatient heart (as the masculine line, representing the heart, tends to move), a sagging head (like water flowing downward), the thin hoof (as the feminine line on either side is seen as smallness), dragging (its hoofs as the feminine tends to remain still). Referring to the carriage, it is associated with lots of man-made calamities (as it travels in the perilous abyss), and progress without obstruction (like water flowing freely). It denotes the moon (like the masculine brightening in darkness formed by the shaded feminine), and the bandit (is as perilous as the abyss). Referring to the tree, it denotes rigidity with lots of thorns (like its solid line surrounded by the broken lines).
Li has the characteristic of clinging and represents fire. It also denotes the sun, the lightning (as fire creates brightness), the armour, and weaponry (as Li has rigid surface on either side). Referring to humans, it denotes the big belly (as the tender feminine line in the middle is seen as the fat). It is a hexagram of dryness (as fire is dry), the tortoise, the crab, the spiral shell, and the clam (as all they have tender flesh inside with rigid shell outside like Li). Referring to the tree, it denotes (a tree that is) hollow and withered above (like Li with the void feminine in the middle and blazing upward).
Gen has the characteristic of keeping still and represents the mountain. It also denotes a footpath (as the path on the mountain is narrow and tortuous), small stones (as they are part of the mountain), the door (and / or watchtower, as it looks like a door which restrains people from moving in and out), fruit or melon (the solid line is the fruit with a core like the peach, and the broken lines are the seeds of a melon), the door guard (whose job is to stop the trespasser like the mountain stopping people from passing), the finger (as it looks like a hand grasping downward), the mouse (as its feminine lines look like the mouse's teeth protruding from the mouth), various kinds of black-billed birds (as its masculine line tends to move while its feminine lines remain still, they work like the bill of a bird). Referring to the tree, it denotes rigidity with many nodes (as its masculine line looks like the rigid trunk, and the broken line strokes of its feminine lines resemble nodes).
Dui has the characteristic of joy and represents the marsh. It looks like the mouth and tongue which is designated to speak and to convince (others); it also denotes the witch (who uses her mouth to inspire people). It is signified as: to bend and break (as Dui is autumn; trees wither in autumn and their branches can be easily bent and broken apart), to adhere and to separate (like fruits attaching the tree while growing, and falling down in autumn). Referring to earth, it denotes the hard and alkaline land (as the salty lake which it refers to is located in the west). It is the concubine (as in ancient China the younger sister usually accompanies the elder sister in marriage to her brother-in-law).