He Tu Fundamentals
According to Chinese legend, it is said that Fu Xi (伏羲), one of the three sovereigns and five emperors in Chinese mythology, saw a mythological “dragon-horse” emerge from the Yellow River. It had black and white dots on its back, arranged in a specific pattern now known as He Tu (河图), the Yellow River Diagram.
From the He Tu diagram, we can see that it is make up of black and white dots, and the number of white dots is odd (Yang), and the number of black dots is even (Yin). The arrangement of the dots is as follows: 1 white and 6 black dots (1 – 6 pair) at the bottom; 2 – 7 pair at the top; 3 – 8 pair at the left; 4 – 9 pair at the right; 5 – 10 pair in the central position.
From such arrangement, we can come to an awareness of certain key principles.
(1) – No Birth without Yin, No Growth without Yang
Odd numbers being Yang and even numbers being Yin, from the He Tu, one can observe that for each of the five directions (including the central position), it is comprise of both one Yang and one Yin number; Yin and Yang coexist together.
(2) – Birth Numbers and Completion Numbers
From the He Tu, the difference between each of the 5 pairs (1 – 6, 2 – 7, 3 – 8, 4 – 9, and 5 – 10) is 5, and 5 being situated at the center, the He Tu numbers are hence separated by the number 5 in the middle. Thus, the inner ring of numbers 1, 2, 3, and 4 belongs to one group, known as Birth Numbers (生数) whereas the outer ring of numbers 6, 7, 8 and 9 belongs to another group, known as Completion Numbers (成数).
(3) – Positioning of the Five Elements
Traditionally, the direction north is at the bottom of compasses or maps in ancient China. Hence, the direction south is at the top of compasses or maps. Being on the northern hemisphere, houses in China traditionally are predominantly built facing south for better accessible to sunlight (Fire) and protection of cold (Water) from the north.
Hence, together with the He Tu arrangement, we have:
- 1 – 6 at the bottom of He Tu (North) with the element of Water
- 2 – 7 at the top of He Tu (South) with the element of Fire
- 3 – 8 at the left of He Tu (East) with the element of Wood
- 4 – 9 at the right of He Tu (West) with the element of Metal
- 5 – 10 at the center of He Tu with the element of Earth
(4) – Production Cycle of Five Elements
Knowing the position of the Five Elements in He Tu, one can observe that (1 – 6) water nourishes (3 – 8) wood, (3 – 8) wood produces (2 – 7) fire, (2 – 7) fire produces (5 – 10) earth, (5 – 10) earth produces (4 – 9) metal and (4 – 9) metal produces (1 – 6) water, a clockwise production cycle of the Five Elements in He Tu.