The first Four Trigrams are Yin:
SUN
Sense/Sensing. The sensing is defined by the weak yin line, outside, at the bottom. The indication gentleness, to be soft and penetrating; the continuing flow of experience: receiving one impression, freed to move on to a new one. The image is grass, wind & wood. The wind goes softly through trees & grass.
LI
Think/Thinking. Thinking links up and attaches sense with words, following the wishes and impulses. Thinking has a beginning and end, visualized in the image of fire; light & clinging. Thinking, is not an end in itself; but to solve problems. You should not think beyond the solution. Once you understand; answers are all in memory. The motivation is to attain clarity, not the thoughts themselves.
TUI
Feel/Feeling. Feelings experience the inner signals, as opposed to the outer signals of senses. The image is the clear lake which you can look through. The indication is for joy and happiness; to to satisfy the needs, so they disappear, to have peace and serenity together. But not to share empathy pity, or suffer with one another.
KUN
Will. The image is a cave in the Earth and extends to the vastness of the planet. The indication is devotion and receptivity; willing to receive the germ and let it grow. Once the will is expressed through choice, or decision; it is to move on and be transported to a higher level of responsibility.
The next Four Trigramsare Yang.
KEN
Body. The body is. You are unable to change it's nature; The image is the mountain, the motivation is keeping still. You can then experience the nature of the body, sense it's needs and control it's functions through the tranquility of silence, of deep sleep or illness.
KAN
Soul. The soul is between heaven, earth,spirit and body. It is always in danger. The Soul, like the river, has to flow from the source in the mountain to the sea, then be transformed, die, into clouds, and finally be reincarnated again as rain in the mountains. The indication is stillnesss and resting. Kan is seen representing Six primary relations of the family: Brother, Sister, Father, Mother, Son & Daughter.
CHEN
The Spirit, attained only in the waking state, the conscious quest. It is always a sacred spirit. It is defined by the images of thunder and lightning, and the indication is arousal, movement and excitement. First you experience awe and anxiety, then humility and peace; then laughter; when you find simplicity in knowing.
CH'IEN
Awareness/Balance here means living in tune with Karma. The image is the heavens on a clear starry night. The motivation is creativity and cosmic awareness towards personal growth & transcendence.