後天八卦次序 Post-Natal 8-Trigrams Order
說卦傳曰乾天也故稱乎父坤地也故稱乎母震一索而得男故謂之長男巽一索而得女故謂之長女坎再索而得男故謂之中男離再索而得女故謂之中女艮三索而得男故謂之少男兌三索而得女故謂之少女
| 次序 Order | 後天八卦 Post Trigrams | 索 Application |
|---|---|---|
| 父 father | 乾☰000 | 天HEAVEN |
| 母 mother | 坤☷111 | 地EARTH |
| 長男 the oldest son | 震☳011 | 一索 first application |
| 長女 the oldest daughter | 巽☴100 | 一索 first application |
| 中男 the second son | 坎☵101 | 再索 second application |
| 中女 the second daughter | 離☲010 | 再索 second application |
| 少男 the youngest son | 艮☶110 | 三索 third application |
| 少女 the youngest daughter | 兌☱001 | 三索 third application |
Shuogua Zhuan ctext states:
- ☰HEAVEN is (the symbol of) heaven, and hence has the appellation of father
- ☷EARTH is (the symbol of) earth, and hence has the appellation of mother
- ☳THUNDER shows a first application (of ☷EARTH to ☰HEAVEN), resulting in getting (the first of) its male (or ⚊YANG), and hence is called ‘the oldest son.’
- ☴WIND shows a first application (of ☰HEAVEN to ☷EARTH), resulting in getting (the first of) its female (or ⚋YIN), and hence is called ‘the oldest daughter.’
- ☵WATER shows a second application (of ☷EARTH to ☰HEAVEN), resulting in getting (the second of) its male (or ⚊YANG), and hence is called ‘the second son.’
- ☲FIRE shows a second application (of ☰HEAVEN to ☷EARTH), resulting in getting the second of its female (or ⚋YIN), and hence is called ‘the second daughter.’
- ☶MOUNTAIN shows a third application (of ☷EARTH to ☰HEAVEN), resulting in getting (the third of) its male (or ⚊YANG), and hence is called ‘the youngest son.’
- ☱LAKE shows a third application (of ☰HEAVEN to ☷EARTH), resulting in getting (the third of) its female (or ⚋YIN), and hence is called ‘the youngest daughter.’