Originally the world contained nothing but emptiness. It all commenced with the appearance of day and night, and then that of spring, summer, autumn and winter. Afterwards, the eight elementary substances of heaven and earth, fire and water, wind and thunder as well as mountains and marshes were formed. With their development the world was at last full of variety.

A spaceless and timeless world (無wu2極ji2: no ridgepole, in Yi’s terminology, which means no boundary, like that of a non-existent house or world due to the lack of a ridgepole to support a roof or dome.)

In the beginning there was neither space nor time; the matrix of the cosmos existed in a form of invisible energy wherein the positive and negative forces were equal and integrated. Then like the start of the cosmos, the two energies began circling, thereby giving way to the creation of polarity (i.e. the origin of the whole of creation).

The polarities (兩liang3儀yi2: two regulated categories, like two semi-domes of the heavens which are divided and sustained by a ridgepole)

The polarities are composed of Yang and Yin which emerged from the heavens in the form of brightness and darkness, like day and night. These two are opposites yet symbiotic as shown on Tai4 Ji2 Tu2 (太極圖, i.e. a drawing of the great ridgepole); one is white with black in its centre, while the other is black with white in its centre. When one increases, the other will decrease. Conversely, when one decreases, the other will increase accordingly.

Yang is converted into things of masculinity and presents itself on the earth in the form of largeness, firmness (or rigidity) and strength - as well as the male. In a hexagram it expresses itself as a masculine line which tends to move.

 Yin is converted into things of femininity and presents itself on the earth in the form of smallness, softness (or tenderness) and weakness - as well as the female. In contrast to the masculine Yang, it expresses itself in a hexagram as a feminine line and tends to remain still.

Additionally, in Chinese culture Yang and Yin refer to opposites in other respects as well, for instance, good or evil (in terms of personality, being either a gentleman or a villain), existence (expressed in various forms, such as solidness, fullness, etc.) or non-existence (such as hollowness, void or emptiness, etc.), this world or the realm of the dead, and warmness (created by sunlight) or coldness (the absence of sunlight).

Four dualities (四si4象xiang4: four phenomena, like those of dawn, midday, dusk and midnight created by the revolution of the heavens)

Once Yang (in the form of brightness) and Yin (as darkness) start to interplay, time comes into existence as darkness changes to brightness at dawn. Brightness continues to develop until it reaches its maximum peak at midday. Then, it begins to decline until dusk when brightness changes to darkness.

With the reciprocal increase and decrease between Yang and Yin in the form of warmness and coldness, spring, summer, autumn and winter are created. The revolution of day and night, as well as four seasons makes the Qi (氣) of the world move. Qi is an invisible power which permeates the human body and the world.

Eight trigrams (八ba卦gua4, i.e. eight symbolic signs for the eight elementary substances of the world)

Qi circulates and the world, which is basically composed of the heavens along with earth and life, is created. The trigram is born as a manifestation of those three essences (參san3才cai4, i.e. three sprouting plants which are teeming with abilities to flourish): the heavens, earth and humanity.

The heavens and earth are positioned; the mountain and the marsh are shaped; the thunder arouses all life; the wind starts blowing; fire is ignited and water condenses; the eight elementary substances of the world are created.

The polarities give birth to four dualities and the four dualities then create eight trigrams. Respectively, Qian2, Kun1, Zhen, Xun, Kan, Li, Gen and Dui are formed.

Thus, the eight elementary substances are represented by eight trigrams in accordance with the image of each trigram and its relevant characteristics.

Qian2 features creativeness and perseverance; it denotes heaven. It is composed of three strong and firm masculine lines. These three masculine lines act together, signifying perseverance like that of the heavens which persists in the revolutions of day and night, season after season. Therefore, it is as dignified as Heaven, originates the world and is symbolic of creativeness.

Kun1 features submissiveness and denotes earth. Composed entirely of feminine (tender) lines, it is submissive as earth faithfully sustains the heavens. It also features receptiveness and expansiveness as earth accommodates the whole of creation and expands endlessly to the horizon. In ancient times, people did not know that the Earth exists in the form of a planet; therefore earth in the I Ching stands for the physical land on which humans live.
　

Zhen4 features movement and denotes thunder. The masculine tends to move upward while the feminine remains still, therefore it quakes as thundering. The masculine line driving the feminine lines, like thunder arousing all life, is signified as “to move”.

Xun4 features entrance or coming into; it denotes the wind. The feminine line makes its way in amongst the heavy masculine lines and remains tame beneath. Therefore, in addition to entrance, it also expresses prostration, i.e. it submissively lowers itself beneath the masculine. On some occasions Xun4 is referred to as modesty and obedience. It represents the wind, as the wind can penetrate everywhere.

Kan3 features the abyss and denotes water. It shows a river running though rapids; therefore it denotes water (, the oracle bone scrip of water). It also looks like earth sinking in the middle wherein a masculine line is trapped by two feminine lines plunging it into an abysmal situation.

Li2 features clinging and denotes fire. It is a trigram wherein two masculine lines cling to one feminine line, like a flame with brightness (masculine) outside and darkness (feminine) inside as fire must cling to wood in order to burn.

Gen4 features keeping still and denotes the mountain. The feminine lines remain still internally while the masculine line outside reaches the end, suggesting a stop due to self-restraint and external restriction. Gen represents the mountain as the rigid masculine line creates a barrier on earth resembling a mountain, which stands still and restricts people in their travels.

Dui4 features joy and denotes the marsh. The tender (feminine) line appears outside the rigid (masculine) lines showing a pleasant countenance; therefore it features joy. Differing from the water depicted by trigram Kan, Dui has water only at the top; therefore it represents the marsh. It also looks like a mouth; therefore it is signified as “to speak” and “to convince” as well.

64 Hexagrams

Henceforth, the eight trigrams interplay and pair with one another forming the 64 hexagrams. Looking as if hanging upside down from the heavens, the image of each hexagram illustrates the oracle. Each hexagram has a specific subject and its 6 lines represent the different space and time manifestations in the era or world of this particular subject. The lines perform according to their positions and statuses, as well as their virtues and abilities. Thus, the whole complex variety of life is covered and displayed through the 64 hexagrams and detailed through their lines.