LATER HEAVEN NUCLEAR FAMILY
The Later Heaven nuclear family was radically changed from the Earlier Heaven system.
It didn’t have a clear relationship to the seasons and cycles. It had a different foundation.
This system was based on the odd or even nature of the trigram.
Broken lines are even numbers and solid lines are odd numbers. When the numbers of the three lines in each trigram were added together the even numbered trigrams would be the female ones, and the odd numbered trigrams would be the male ones.
Three broken lines (3 even numbers) would result in an even total 2+2+2=6. This was the trigram for the mother, the most yin.
All the daughters have one broken line and two solid lines (1 even and 2 odd numbers) The one with the broken line on the bottom in the first place was the first daughter. The one with the broken line in the middle would be the second daughter, and the one with the broken line on top would be the third daughter.
The three solid lines (3 odd numbers) would result in an odd total 3+3+3=9. This was the trigram for the father, the most yang.
All the sons have one solid line and two broken lines (1 even and 2 odd numbers) The one with the solid line on the bottom in the first place was the first son. The one with the solid line in the middle would be the second son, and the one with the solid line on top would be the third son.
In comparison to the Earlier Heaven arrangement, the trigrams for the mother, father, first son and first daughter remained the same. The trigrams for the second and third son in Earlier Heaven became the trigrams for the second and third daughter in Later Heaven. And the second and third daughters took on the trigrams of the second and third son in Later Heaven version.
The second and third sons were given feminine attributes and negatively interpreted.
The second and third daughters were given masculine attributes and were interpreted as if the were women of poor character…too aggressive!
This gave the first son and first daughter the only good interpretations and it gave them priority status.
After three thousand years of application, China was able to set up a system where people could only have one child. This was explicitly against the concept of the nuclear family and it benefits.
The system of Later Heaven opened up new depths and insights to the changes and subsequently to the hexagrams. It was a new era of mathematical deduction filled with many great ideas and association.
Unfortunately, in the Nuclear Family the second and third sons and daughters were marginalized. This bias permeated the interpretations on the hexagrams as they evolved. At the same time the random selections of hexagrams through divination allowed an access that was not astrologically or seasonally aligned. It has worked well for divination for thousands of years, but something was lost in the accuracy seasonal or natural cycles. Hexagrams were understood abstractly but the relationship to nature became veiled or somewhat filtered out. What was simple in nature became abstracted and obscured. A new mystery of profound associations became established at the expense of natural spontaneity.