TL;DR: Tiến thần and thoái thần are two rules for reading moving lines in Lục Hào, based on a moving line transforming into a new line of the same element. If the branch of the transformed line moves in the increasing direction of the element, it is called tiến thần; if it moves in the decreasing direction, it is called thoái thần. The book Tăng san bốc dịch lists 7 advancing pairs and 7 retreating pairs, and stresses that the day and month along with generating and controlling factors must all be weighed, not the names alone.
What Are Advancing and Retreating Spirits in Liu Yao?
Advancing spirit and retreating spirit are two terms in Liu Yao, used to indicate the direction of movement of a line when it moves and changes into another line. When a moving line changes into a new line of the same element as the old line, one compares the branches of the two lines to see whether it is going up or down within the 12 branches. If the branch goes up in the order Zi, Chou, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu, Hai, it is called advancing; if the branch goes in the opposite direction, it is called retreating. This understanding has long existed in the divination tradition, and was systematized by the book Zeng Shan Buo Yi into a separate chapter, chapter 29, titled "Advancing Spirit and Retreating Spirit".
The book begins the chapter with a definition: advancing and retreating are matters of a moving line changing into another line, and depending on the matter being asked, what one desires should advance, and what one fears should retreat. In other words, advancing or retreating is not inherently good or bad, but must be placed in the specific question.
Table for Identifying Advancing and Retreating Spirits
Zeng Shan Buo Yi lists all the pairs, based on the principle of the same element and moving in the increasing or decreasing direction of the 12-branch sequence. The table below summarizes exactly the pairs the book records.
| Element | Advancing spirit (going up) | Retreating spirit (going down) |
|---|---|---|
| Water | Hai changes to Zi | Zi changes to Hai |
| Wood | Yin changes to Mao | Mao changes to Yin |
| Fire | Si changes to Wu | Wu changes to Si |
| Metal | Shen changes to You | You changes to Shen |
| Earth | Chou changes to Chen, Chen changes to Wei, Wei changes to Xu | Xu changes to Wei, Wei changes to Chen, Chen changes to Chou |
The point to note is that the Earth element has as many as three advancing pairs and three retreating pairs, because Earth occupies the four branches Chou, Chen, Wei, Xu in increasing order. The other elements each have only one pair, since each element occupies only two branches in the 12-branch cycle.
Why Is the Advancing Spirit Considered Going Up and the Retreating Spirit Going Down?
The explanation given by the book is quite vivid. The advancing spirit is compared to plants in spring, with lush branches and leaves, while the retreating spirit is compared to plants in autumn, gradually losing leaves. This comparison shows that advancing and retreating are not just about the branch, but are also linked to weather and the rhythm of growth.
In this chapter, the author Ye He Lao Ren further divides the advancing spirit into four cases, depending on the state of the moving line and the changed line:
- The moving line is prosperous, and the changed line is also prosperous: it advances immediately according to the rising momentum.
- The moving line is declining, and the changed line is also declining: one must wait for the time before it can advance.
- One of the two lines is declining: one must wait until the day when that line is prosperous before it can advance.
- One of the two lines meets emptiness or monthly destruction: one must wait until the day of filling emptiness or filling destruction before it can advance.
The retreating spirit also has four similar cases, but in the opposite direction: sometimes it is prosperous so it does not retreat immediately, sometimes it is declining so it retreats immediately, sometimes one must wait for the line to decline before it retreats, sometimes one must wait for the day of filling emptiness or filling destruction before it retreats.
How to Distinguish the Advancing Spirit from Other Types of Change?
The advancing spirit is only one of many types of change of a moving line. Beginners often confuse the advancing spirit with change by generation, change by control, change into emptiness, change into monthly destruction, or change back to the old line. The simplest way to distinguish is to examine two points: whether the changed line has the same element as the moving line, and whether the branch of the changed line moves in the increasing direction of that element.
- If the same element and the branch goes up: advancing spirit.
- If the same element and the branch goes down: retreating spirit.
- If a different element: it is not advancing or retreating, but change by generation, change by control, or change into another element.
- If the changed line turns back to control the moving line: it is called change turning back to control, calculated separately.
One point in this chapter is easy to miss, and it comes from Lý Ngã Bình: once a moving line sits on the day or the month, "meeting emptiness it is not empty, meeting break it is not broken" (逢空不空，逢破不破), let alone when it merely changes into emptiness or monthly break. He compares the day and month to the sky: a line changing into emptiness or break is only a drifting cloud covering the sun, and when the day of filled emptiness or filled break comes the cloud clears. Here the book argues against the Dịch mạo (易冒), which held that a moving line on the day or month that changes into emptiness or break "has no step and no road" and cannot advance.
Examples in Zeng Shan Buo Yi Showing How Advancing and Retreating Operate
Zeng Shan Buo Yi uses many examples to illustrate, and these examples show that advancing and retreating do not stand alone but must be read together with other lines.
In the first case, on the day of Gui Mao in the month of Shen, asking about the provincial examination, the hexagram Heng changed to Da Guo. The fifth line was the Officer Ghost Shen Metal moving, changing to You Metal, that is, an advancing spirit. The book judged that You Metal as the officer star holding the World was prosperous, was set in hidden motion by the clash of the Mão day, and was also helped by the Officer line in the fifth place changing into an advancing spirit, with Wealth supporting it, so not only would one pass this examination but also the next. The result was exactly as predicted: the person passed successively.
In the second case, on the day of Yi Chou in the month of Mao, asking whether a marriage proposal would succeed. The wealth line holding the World was Wei Earth moving, changing to Xu Earth, that is, an advancing spirit, and the Descendant line Si Fire moved to generate the World. But Si Fire changed to Zi Water, turning back to control. The book judged that one must wait until the day of Wu, when Wu clashes to open Zi Water and also combines with the World Wei, then the matter would succeed. Indeed, on the day of Wu the girl's family agreed. In this hexagram there was also the Officer Ghost You Metal moving and changing to Shen Metal, that is, a retreating spirit, and the book judged that even if there were obstacles, those obstacles would be weak and not enough to ruin the matter.
In the third case, on the day of Jia Chen in the month of You, asking about a matter of self-defense. The hexagram showed the World changing back to control, the Officer Ghost changing to a retreating spirit, and the Descendant changing to an advancing spirit. The book judged that all three lines were not good signs, an omen of great misfortune. The result was exactly as predicted: the next year one was dismissed from office and interrogated.
In the fourth case, on the day of Bing Xu in the month of Chou, asking whether the father had sent a letter saying he had set out, and whether going to meet him would result in a meeting. The parent line Xu Earth moved and changed to Wei Earth, that is, a retreating spirit, so it was judged that the father was already on his way home. The World line was Shen Metal moving and changing to You Metal, that is, an advancing spirit, showing that the questioner wanted to go. The parent line generates the World, so they would certainly meet on the day of Wei. Indeed, they met exactly on the day of Wei.
What Do Other Books Say About Advancing and Retreating?
The chapter is written to refute a doctrine of older books. After each case the book recalls the "old method": a moving line on the day or month that changes into emptiness or monthly break is held not to advance or retreat, and a moving line that is broken or scattered but changes into the day or month is held to fall short of advancing or retreating. The book then sets its verified cases against this. The case of going to meet the father above is one of them: the Tuất line changing to Mùi was both broken and empty, and the Mùi day, the day when emptiness and break were filled, was exactly the day of the outcome.
At the end of the chapter the book records the words of Lý Ngã Bình, who is named as the examiner of the book. He says he first read the Dịch mạo and later saw that the doctrine "a moving line on the day or month that changes into emptiness or break does not advance" was wrong. To the second doctrine, that a moving line which is broken or scattered and changes into the day or month "has lost its place, so how can it go forward", he answers: a line that moves and is broken will have its day of filled break, a line that moves and is scattered will have its day of being filled; all the more when it changes into the day or month, which is called changing into strength, and after being filled it is stronger still, so how can it be said not to advance. He also remarks that the other chapters of the Dịch mạo keep verified cases while this one keeps only a few model charts, so he knows it is conjecture rather than something drawn from experience.
This way of reading shows that advancing and retreating in Liu Yao is not a closed formula, but a slice of the whole system of interpretation including the moving line, the changed line, the day and month, generation and control, emptiness, monthly destruction, and also the specific question.
Nhat Nguyet's Suggestions
When learning advancing and retreating spirits, one should start by correctly memorizing the seven advancing pairs and seven retreating pairs, because this is the fixed part, easy to check. After that, one practices placing advancing and retreating into context: what the question desires, which line is the useful spirit, which line is the unfavorable spirit, and which side the day and month are supporting. Beginners often feel happy when seeing an advancing spirit and worried when seeing a retreating spirit, but Zeng Shan Buo Yi itself warns that advancing and retreating must be read according to the question, and do not inherently carry good or bad meaning.
One more thing to remember is that advancing and retreating spirits are only a convention of Liu Yao, not a natural law. They have value within the system, helping learners have an additional criterion to read the direction of movement of a line. Outside that system, there is no basis to assert that an advancing spirit or retreating spirit reflects anything about the real world.
