Section 50.1
In the grand design of Heaven’s Way, things that are mutually opposed are not permitted to emerge together. Such is the case with yin and yang.
In spring, yang emerges while yin withdraws;
in autumn, yin emerges while yang withdraws;
in summer, yang moves to the right while yin moves to the left;
in winter, yin moves to the right while yang moves to the left.
When yin emerges, yang withdraws;
when yang emerges, yin withdraws.
When yin moves to the right, yang moves to the left;
when yin moves to the left, yang moves to the right.
This is why
in spring both are in the south;
in autumn both are in the north;
yet they do not share [the same] circuit.
In summer they intersect in the front;
in winter they intersect in the rear,
yet their pattern is not the same.
They circulate simultaneously but do not disrupt each other;
they cross [paths], but each maintains its respective duties.
This is called Heaven’s intention.
How does [Heaven] discharge its business? Heaven’s Way [is such that] with the approach of the beginning of winter, yin and yang each come from their respective quarters and shift to the rear:
Yin comes westward from the eastern quarter,
and yang comes eastward from the western quarter.
Arriving at the middle month of winter, they meet each other in the northern quarter, where they combine to become one. This is called the [“winter] solstice.” They then divide and withdraw from each other,
yin heading to the right
and yang heading to the left.
Those that head left follow a compliant path;
those that head right follow a retrograde path.
Retrograde qi moves to the left and ascends;
compliant qi moves to the right and descends.
Thus
what descends warms,
what ascends chills.
From this it can be seen that in winter,
Heaven moves yin to the right and yang to the left.
Heaven promotes what is to the right and demotes what is to the left.
When the winter months draw to their conclusion, both yin and yang return to the south.
When yang returns to the south, it emerges at yin [the third position];
when yin returns to the south, it withdraws at
xu [the eleventh position].
1These are the manifestation points of yin and yang when they first emerge from the earth and withdraw into the earth.
Arriving at the middle month of spring,
yang lies due east,
and yin lies due west.
This is called the “spring equinox.” At the spring equinox, yin and yang are evenly divided. Therefore,
day and night are of even length;
cold and heat are of equal proportion.
Yin daily decreases and gives way to yang;
yang daily increases and strengthens.
Thus warmth and heat are produced.
At the beginning of the month of the height of summer, [yin and yang] meet each other in the southern quarter where they combine to become one. This is called the [“summer] solstice.” They then divide and withdraw from each other.
Yang heads to the right;
yin heads to the left.
Heading left, [yin] comes from below;
heading right, [yang] comes from above;
[what comes from] above heats;
[what comes from] below chills.
From this we see that in summer,
Heaven moves yang to the right
and moves yin to the left;
promotes what is to the right
and demotes what is to the left.
When the summer months draw to their conclusion, both yin and yang return to the north.
When yang returns to the north, it withdraws at shen [the ninth position];
when yin returns to the north, it emerges at chen [the fifth position].
These are the manifestation points of yin and yang when they first emerge from the earth and withdraw to the earth.
Arriving at the middle month of autumn,
yang lies due west,
and yin lies due east.
This is called the “autumn equinox.” At the autumn equinox, yin and yang are evenly divided. Therefore,
day and night are of even length;
cold and heat are of equal proportion.
Yang daily decreases and gives way to yin;
yin daily increases and strengthens.
Thus, arriving at the third month of autumn, frost begins, and arriving at the first month of winter, cold first arrives. [At the time of the] “Light Snow,”
2 all things are mature. [By the time of the] “Great Cold,”
3 things are gathered together and stored away, as the achievements of Heaven and Earth are brought to a conclusion. [50/55/22–50/56/5]