Eight Trigrams

The Eight Trigrams are three-line figures that classify features of the natural world and provide the basic patterns for constructing the hexagrams. In the book’s account, they stand between the elementary whole and divided lines and the six-line figures interpreted as moral, social, and political counsel. Their significance thus lies not only in what they symbolize, but in how combinations of lines become a system for describing circumstances and guiding decisions.

Form, Names, and Natural Associations

The text attributes eight trigrams to the primordial observer Fuxi, who looks upward to the forms of the sky and downward to the patterns of the earth. He also observes birds and beasts, the differing suitability of soils, and phenomena near at hand in the human person as well as at a distance in the wider world. From this survey, the traditional account says, he devises the three-line figures to display nature’s subtle operations and classify the qualities of the myriad things. The account describes the process and purpose in broad terms, without explaining precisely how observation produced each sign.

The eight figures are named as representations of heaven or sky; water in the form of a marsh or lake; fire, the sun, or lightning; thunder; wind and wood; water as rain, clouds, springs, streams in defiles, or the moon; a hill or mountain; and the earth. Each is associated with an attribute suggested by its natural referent, although the discussion postpones a fuller treatment of those attributes. The range of associations already shows that a trigram does not simply label one isolated object: some gather several related phenomena under a single figure, while others connect a natural form to a broader quality.

How the Figures Are Formed

A second account describes the figures as a sequence of combinations. The Great Ultimate produces the two elementary forms, a whole line and a divided line; these form four emblematic symbols when placed in pairs, and the symbols, with another line added successively, produce the Eight Trigrams. The construction makes the trigrams a stage in an expandable lineal system: the same two elementary marks can be recombined into the larger figures, including the six-line hexagrams.

The commentator distinguishes the visible mechanics of this sequence from the less certain claim about its first cause. The whole and divided lines, their paired forms, and the resulting trigrams can be exhibited clearly; what the Great Ultimate means, and how it could produce the first two lines, remains obscure to him. He rejects the later image of a circle as an unsatisfactory explanation of that process. He considers the account based on line combinations the most credible explanation of the figures’ formation, while noting a separate tradition that derives them from a mysterious scheme associated with the Yellow River. In his judgment, that tradition appears intended to give the trigrams supernatural authority, and the form of the scheme itself may not preserve its original appearance.

Trigrams Within the Hexagrams

The Eight Trigrams also function as the constituent patterns of the sixty-four hexagrams, each of which consists of six whole or divided lines. The book distinguishes the trigrams’ natural associations from the meanings assigned to the complete figures: the hexagram texts interpret the six-line structures in relation to human affairs, and the significance of an individual line depends on the hexagram’s subject as well as its position. Reading the trigrams therefore requires attention to both local line structure and the larger figure into which the lines are composed.

The commentator outlines positional rules that help explain how lines acquire force in a hexagram. The first, third, and fifth places are treated as correct for whole lines, while the second, fourth, and sixth are correct for divided lines. Lines also correspond across the two trigrams: the first and fourth, second and fifth, and third and sixth are paired, with a complete correspondence requiring unlike qualities, one whole and one divided. The middle positions of the trigrams—the second and fifth places in a hexagram—have particular force. When a ruler or commander occupies the fifth position, the second may represent a capable minister or officer; their complementary action can signify a beneficial and successful outcome. These relations do not yield meaning independently of the figure: the hexagram’s name and subject determine how its lines apply.

Divination and Interpretation

The trigrams are connected in the book to a long practice of divination, but the commentator distinguishes consultation about the prospects of a contemplated course from certain knowledge of future events. The use of divining stalks is associated with early Chinese sources alongside tortoise-shell divination. In the described procedure, forty-nine stalks are manipulated three times for each line, requiring eighteen manipulations to form a hexagram. Odd numbers yield strong, undivided lines and even numbers weak, divided ones; the numbers 9, 8, 7, and 6 are assigned to the emblematic symbols and take part in forming the figure. Once it has been formed, the operator turns to the whole-hexagram judgment attributed to King Wen and the emblematic line statements attributed to the Duke of Zhou for interpretation.

The commentator treats the stalks’ supposed spiritual virtue as a belief expressed by the appendix, not as proof that divination can disclose events in advance. He argues that the procedure uses numbers to construct the lineal figure rather than treating number as the underlying substance or cause of things. He also warns that the appendix’s language about knowledge of the future can mislead a cursory reader: its practical concern, as he understands it, is whether plans and anticipated conditions will turn out auspiciously or disastrously. In this account, the trigrams are at once symbolic patterns and components of a procedure, but their interpretive use remains bounded by the question being asked and by the judgments attached to the resulting hexagram.

Competing Accounts and Limits of Interpretation

The book preserves more than one account of where the trigrams come from. The account of Fuxi presents their invention as a response to close observation of nature; the line-generation account explains their structure through the combination of whole and divided marks; and the River scheme tradition gives their origin a supernatural cast. The commentator does not treat these explanations as equally persuasive. He favors the combinatorial account as a workable explanation of how the figures can be formed, while regarding the supernatural scheme as a later attempt to enhance their religious authority.

He also resists reading a fully developed cosmology into the line vocabulary. The appendix relates the lines to the ways of heaven, earth, and humanity, and uses terms including yin and yang, strength and weakness, benevolence and righteousness. But the commentator argues that the text’s central concern is changing phenomena in nature and human experience, not an abstract theory of primordial matter or creation. His distinctions—between figure and interpretation, procedure and claimed efficacy, and early textual meaning and later philosophical elaboration—make the Eight Trigrams important not as a self-explanatory code, but as a structured vocabulary whose uses and meanings must be established in context.