1. The light trigrams have more dark lines, the dark trigrams have more light lines.
The "light" trigrams are the three sons, Chên, ☳, K'an, ☵, Kên, ☶, each of which consists of two dark lines and one light line. The "dark" trigrams are the three daughters, Sun, ☴, Li, ☲, and Tui, ☱, each of which consists of two light lines and one dark line.
2. What is the reason for this? The light trigrams are uneven, the dark trigrams are even.
The light trigrams are made up of the lines 7+8+8, or 7+6+8, or 7+6+6, or 9+8+8, or 9+6+6, or 9+6+8. Using the relevant numbers, the numerical values of the lines in the dark trigrams can be found in the same way. Hence the sum of the values of the lines in light trigrams is always an uneven number, and the line representing the uneven number [an undivided line] is therefore the determinant of the light trigram. In the case of dark trigrams, the reverse is true.
3. What is their nature and how do they act? The light trigrams have one ruler and two subjects. They show the way of the superior man. The dark trigrams have two rulers and one subject. This is the way of the inferior man.
Where one alone rules, unity is present, whereas when one person must serve two masters, nothing good can come of it. This truth is here more or less accidentally linked with the structure of the trigrams.