TL;DR: A Lục Nhâm course type is the name given to a divination, assigned by the generating and overcoming relations between the four courses and the three transmissions, not a separate element outside the board. The four most common types are Nguyên Thủ (exactly one upper overcomes its lower, with no lower overcoming its upper), Trùng Thẩm (a lower overcomes its upper), Tri Nhất (several courses overcome alike and the one matching the day stem in yin and yang is chosen, the tỷ dụng method), and Thiệp Hại (those courses all match or all fail to match, so the times each is overcome are counted). This is a classification convention within the Lục Nhâm discipline, not a scientific claim about fate.
What Is a Lục Nhâm Course Type?
A course type is the name of a Lục Nhâm divination, assigned by the generating and overcoming relations between the four courses and the three transmissions. After setting up the four courses and three transmissions, the practitioner compares the configuration of that divination against a catalogue of pre-named "types," then names the divination by that type. The four types Nguyên Thủ, Trùng Thẩm, Tri Nhất and Thiệp Hại arise from the first three of the nine gates, tặc khắc, tỷ dụng and thiệp hại; the later methods such as dao khắc, mão tinh, biệt trách, bát chuyên, phục ngâm and phản ngâm also yield charts with their own names.
It is important to distinguish: a course type is not an independent element added to the divination, but rather a name describing a configuration that already exists. In the Đại Lục Nhâm linh giác kinh, in the first fascicle on spirit courses, the author explains seven types of selecting courses in the sequence: tặc khắc, tỷ dụng, thiệp hại, dao khắc, mão tinh, bát chuyên, biệt trách; only afterward does he discuss phục ngâm, phản ngâm, and other course patterns. Each course is accompanied by an image, an oracular saying, and a verse. This arrangement shows that course type is a layer of classification placed immediately after the four courses and three transmissions are established.
By tradition, Từ Đạo Phù of the Tang dynasty compiled the verse collection Đại Lục Nhâm tâm kính; each verse has annotations citing the classic. The version currently circulating was revised by Qing-era hands from manuscript copies, with reference to excerpts from the Thông thần tập and additions on military divination. This is a traditional attribution; modern scholarship does not consider the date and true authorship of the text to be proven.
How Do the Four Base Types Nguyên Thủ, Trùng Thẩm, Tri Nhất, and Thiệp Hại Differ?
These four types differ in the direction and number of overcoming relations between the courses. The table below summarizes how they are distinguished according to the presentation common in Lục Nhâm manuals.
| Course Type | Identifying Condition | Direction of the Matter in the Discipline's Reading |
|---|---|---|
| Nguyên Thủ | No lower course overcomes its upper, and exactly one upper overcomes its lower | The matter starts from above, from the active side; orderly |
| Trùng Thẩm | One lower course overcomes its upper; it is taken even if an upper overcomes a lower elsewhere | The matter starts from below, from the dependent side; disorderly |
| Tri Nhất | Two or three courses overcome alike, and the one whose upper spirit matches the day stem in yin and yang is chosen (the tỷ dụng method) | The matter arises from people of one's own kind, close at hand |
| Thiệp Hại | Those courses all match or all fail to match the day stem, so one counts how often each is overcome on its way home | The matter is hard and slow, passing many obstacles |
Note that this is a table describing convention, not a table for looking up results. The same type name, depending on accompanying spirit indicators and the question, may yield different judgments. The manuals do not fully agree on the names: the Linh giác kinh calls Nguyên Thủ the "thủy nhập" pattern[1], the Lục Nhâm đại toàn says Trùng Thẩm is "also called thủy nhập"[5], and a note in the Tâm kính distinguishes a lone lower-overcomes-upper as thủy nhập, keeping the name Trùng Thẩm for when an upper-overcomes-lower is also present[2]. Practitioners should state clearly which manual's convention they follow.
Nguyên Thủ
Nguyên Thủ is when no lower course overcomes its upper and exactly one upper overcomes its lower; that course is taken as the active line[1]. On the oracular saying for Nguyên Thủ, the Linh giác kinh roughly states that this course is orderly and its responses are easy to know: a matter within the year responds by year, within the month by month, within the week by week, within the day by day. The manual advises the diviner to write the year, month, day, week, and seasonal node into the figure for cross-reference. It also says this course suits movement more than stillness, and starting before more than following after.
The same manual cites a saying of Gia Cát Lượng (Khổng Minh) on the words "nguyên thủ": as the head is what stands at the top of a body, and a body without a head cannot be a body, from this one infers the meaning of seniority. That citation poses a reverse question to the diviner: if the upper course overcomes the lower course, one must ask oneself whether one is truly in a superior position, truly the side that initiates first, truly in a state of vigor and support. If all these conditions are met, it is favorable; if not, the side that initiates first may be overwhelmed by the side that responds later.
The manual also cites Master Thiệu (邵子) saying "the young should not consult Nguyên Thủ," for fear of harm to elders and because it signifies joy first and worry after. This is an admonition within the school, not a natural law, so it should be read as a caution rather than a prohibition.
Trùng Thẩm
Trùng Thẩm is when a lower course overcomes its upper (called tặc): that course is taken as the active line even if another course shows an upper overcoming its lower[3]. The Túy ngôn explains the name: the lower offends the upper, so the matter must be examined again and again[3]. If Nguyên Thủ describes a matter starting from the active side, Trùng Thẩm describes a matter starting from the dependent side, rising from below. In the discipline's reading, this is the "disorderly" type in the sense that the upper-lower order is reversed, so in interpretation it is often read as a matter brought by subordinates, outsiders, or external circumstances that one must handle. It must be stressed: this is the discipline's interpretation, not a claim about morality or social order.
Tri Nhất
Tri Nhất literally means "knowing one." It is the name of the chart produced by the tỷ dụng method: when two or three courses overcome alike, the course whose upper spirit matches the day stem in yin and yang is chosen, a yang spirit on a yang day and a yin spirit on a yin day. The Linh giác kinh states plainly that the tỷ dụng course is also called Tri Nhất (比用课又名知一)[1]. Its verse says the matter arises through people of one's own kind, a lost object is taken by a neighbour, and a runaway has not gone far.
Thiệp Hại
Thiệp Hại is the most complex of the four base types. "Thiệp" means to wade across, "hại" here means being overcome. This type appears when the courses that overcome alike all match the day stem in yin and yang, or all fail to match, so tỷ dụng cannot decide. Then each upper spirit travels the earthly plate back to its home palace, the times it is overcome on the way are counted, and the course overcome most is taken as the active line[5]. If they are still equal, a yang day takes the spirit above the stem and a yin day the spirit above the branch[2]. The Lục Nhâm đại toàn reads this type as every matter being hard and slow, gained only after much hardship[5].
Why Is a Lục Nhâm Divination Named by Its Course Type?
Because the course type is a way of reducing the configuration of the whole board to a single name, helping practitioners remember and look up. When setting up a divination, the practitioner follows the sequence: place the heaven plate and earth plate, establish the four courses, issue the three transmissions, and only then determine the course type. The type name immediately indicates which category in the catalogue the divination belongs to, from which one looks up the corresponding oracular section.
The Lục Nhâm đại toàn, a Ming-era compendium edited by Quách Tái Lai, is a large compendium. It presents the heaven plate, earth plate, four courses, three transmissions, course types, and heavenly generals within a single system. The Lục Nhâm túy ngôn by Lưu Xích Giang of the Qing dynasty, in its preface, states it was composed over seven years with three revisions of the manuscript, comprising a first fascicle refuting ten errors, later fascicles supplementing the Tất pháp lectures, gathering and explaining the oracular sections of the Chỉ nam, and then the author's own collection of course verifications. The Lục Nhâm trực chỉ is an anonymous text, without preface and without named compiler; it explains all 720 courses according to the sixty days, from Jia Zi, first configuration, to Gui Hai, twelfth configuration. Each course records the course type, course meaning, explanation, judgment, and sections on weather, household, marriage, illness, seeking wealth, travelers, and military campaigns.
These three works show that course type is not the invention of a single author, but a layer of classification accumulated over generations. For this reason, the catalogues of course types among manuals are not entirely identical in number and name. Some manuals list more than a dozen types, some list several dozen, and some types appear only in one lineage.
Is Course Type a Scientific Claim?
No. Course type is a classification convention within the Lục Nhâm discipline, with a history and a system, but it is not a claim verified by scientific method. One must distinguish three layers when reading any Lục Nhâm document.
- The first layer is calendar data: lunar date, stems and branches, seasonal nodes, hour. This layer can be calculated and cross-checked against a printed calendar or an independent table.
- The second layer is the manual's convention: how to place the heaven plate, how to establish the four courses, how to issue the three transmissions, how to determine the course type. This layer, even when computed, remains the manual's convention, not natural data.
- The third layer is interpretation of results: the judgment for each specific matter. This layer is the discipline's reading, not a conclusion about real people and events.
Practitioners should ask questions at the third layer: on what principle is that judgment based, is it consistent with other divinations, and does it fit the specific question. This way of reading preserves the value of the discipline as a systematic tradition of thought, while not turning it into an absolute claim about a specific person's finances, health, or fate.
Nhật Nguyệt's Suggestions When Looking Up Course Types
When looking up a Lục Nhâm divination, one should record four things: the date and time of the divination according to the calendar, the manual followed for establishing courses, the manual followed for determining course type, and the specific question. These four help later readers cross-check and avoid confusion between lineages. For beginners, start with the four base types and practice on the divinations already available in the Lục Nhâm trực chỉ, since there each course already has its type name recorded for comparison. When two documents give different type names for the same divination, keep both and note which document calls it what, rather than hastily choosing one side.
What Is the Purpose of Reading Course Types?
The course type is a layer of classification that helps the practitioner move from a specific board to a catalogue of distilled oracular sayings. It does not replace reading the four courses, three transmissions, spirit indicators, and heavenly generals, but serves as a label for lookup. Understanding this role correctly helps avoid two extremes: one, treating the type name as the final verdict; two, treating the type name as meaningless. Both are incorrect according to how the source texts present it.
For the general reader, what is worth keeping from this tradition is the spirit of classifying situations by the relations between parties: which side initiates first, which side is dependent, how many paths there are to choose, which path is heavier. That is a way of posing questions useful for decision-making, separate from the part about predicting specific outcomes.
