Lục Nhâm Khóa Thể: What Are Nguyên Thủ, Trùng Thẩm, Tri Nhất and Thiệp Hại?

What is Lục Nhâm khóa thể and why must a chart be named?

Khóa thể is the name of a Lục Nhâm chart, assigned by the shape of the four khóa and the three truyền, not by the question asked. The reader places the nguyệt tướng (monthly general) on the hour of the reading to set the thiên bàn (heavenly plate) over the địa bàn (earthly plate), builds four khóa from the can and chi of the day, then uses a phát dụng (initiating) method to draw the three truyền: Sơ (initial), Trung (middle) and Mạt (final). The chart first carries the name that belongs to the phát dụng method used.

Lục Nhâm đại toàn has twelve quyển (volumes); the summary written for the Tứ khố toàn thư (Siku Quanshu) says the book bears no compiler's name, that the first volume is headed as collated by Quách Tái Lai, judicial officer of Hoài Khánh prefecture, and that it is a Ming printing^[1]. Volume one records the nine phát dụng methods, and volume seven opens the Khóa kinh section with each khóa thể in turn^[1]. The four khóa thể Nguyên Thủ, Trùng Thẩm, Tri Nhất and Thiệp Hại belong to the first three methods: tặc khắc, tỷ dụng and thiệp hại.

Why is the khóa thể name so important?

The khóa thể name gives the overall tendency of a chart: smooth or adverse, whether a matter should be started first or left until later. But the book does not let the reading stop at the name. Đại toàn quotes Tụ trung kim on Nguyên Thủ: "皆以神将吉凶" (good and bad are all judged by the spirits and generals), and the strength of each element by season, the person's year and the three truyền must also be weighed; when an upper khóa overcomes a lower one but the upper spirit is weak and the lower one strong, the lower actually prevails^[1].

What is Nguyên Thủ 元首?

Nguyên Thủ is the chart in which, among the four khóa, exactly one khóa has its upper spirit overcoming its lower spirit and the other khóa have no overcoming; that khóa initiates and becomes the Sơ truyền. The Khóa kinh of Lục Nhâm đại toàn says: "凡一上克下，余课无克，为元首课"^[1]. The book calls it "九宗之元，六十四课之首" (the first of the nine methods, the head of the sixty-four khóa), likens it to a ruler governing a minister, and assigns it to the form of the Càn hexagram^[1].

Its image text opens with "天地得位，品物咸新" (heaven and earth in their proper places, all things renewed), then speaks of employing worthy men, harmony between ruler and minister, and the guest side winning in warfare^[1]. Tụ trung kim says this chart means "尊制卑，贵制贱，占事多顺" (the high governs the low, the noble governs the base, most matters go smoothly) and "凡事宜先，事起男子" (matters should be taken up first, the matter starts with a man)^[1].

What is Trùng Thẩm 重審?

Trùng Thẩm is the chart in which, among the four khóa, exactly one khóa has its lower spirit overcoming its upper spirit (the book calls this the lower "rebelling" against the upper) and the other khóa have no overcoming; that khóa initiates. The Khóa kinh says: "凡一下贼上，余课无克，为重审课"^[1]. The name is explained as the lower offending the upper, like a minister remonstrating with a ruler, who dares not act on his own and must examine the matter again and again before acting; the khóa belongs to the form of the Khôn hexagram^[1].

The image text includes "一下逆上，岂无忧惊", "事宜后起，祸从内生" and "诸般谋望，先难后成" (one lower defies the upper, how can there be no worry; matters should start later, trouble arises from within; every plan is hard first and succeeds later)^[1].

How does Trùng Thẩm differ from Nguyên Thủ?

They differ in the direction of overcoming in the initiating khóa, not in whether that khóa sits on the can or on the chi. Nguyên Thủ is upper overcoming lower; Trùng Thẩm is lower overcoming upper. The tặc khắc method in volume one checks lower overcoming upper first: "取课先从下贼呼，如无下贼上克初" (when taking the khóa, look first for the lower overcoming the upper; only if there is none take the upper overcoming the lower as the Sơ truyền)^[1]. That is why the readings of Nguyên Thủ lean towards acting first and those of Trùng Thẩm towards acting later.

What is Tri Nhất 知一?

Tri Nhất is the chart in which two or more of the four khóa show overcoming, so the khóa whose spirit shares the yin or yang of the day stem must be chosen to initiate. The Khóa kinh says: "凡课有二上克下，或二下克上，择课之阴阳与今日比者而为用神，曰知一课"; on a yang day take the yang spirit, on a yin day the yin spirit^[1]. Volume one calls this method tỷ dụng: "常将天日比神用，阳日用阳阴用阴"^[1].

The name Tri Nhất is explained as two lines moving at once, the matter splitting two ways, so one must know how to choose the one in accord and use it; the khóa belongs to the form of the Tỷ hexagram^[1]. Its image text includes "祸从外起，事向朋谋。寻人失物，近处堪求" (trouble comes from outside, the matter is planned with friends, a missing person or lost thing should be sought nearby)^[1].

What is Thiệp Hại 涉害?

Thiệp Hại is the chart in which two or more khóa show overcoming and the spirits involved either all share the yin or yang of the day stem or all do not, so the tỷ dụng method cannot choose. The reader then counts, from where each spirit stands on the earthly plate back to its home position, how many overcoming positions it passes; the spirit that passes the most initiates. The Khóa kinh says: "与今日俱比俱不比，则以涉地盘归本家受克深处为用，为涉害课" and explains "涉者，度也；害者，克也"^[1].

The image text opens with "风波险恶，度涉艰难" (wind and waves are perilous, the crossing is hard); the book says whoever meets this chart finds every matter difficult and delayed, succeeding only after hardship; the khóa belongs to the form of the Khảm hexagram^[1].

When two spirits pass the same number of overcoming positions a further rule is needed, and Đại toàn itself records two. The verse in volume one reads "孟深仲浅季当休", using the mạnh, trọng and quý positions to set depth; the Khóa kinh in volume seven reads "不论孟仲季比用，止取涉度害克位之最深者" and adds the view of Úy Sơn nhân, who takes the mạnh and trọng positions of the heavenly plate as the standard^[1].

What does the comparison table of the four basic khóa thể include?

The table summarizes the nine methods in volume one and the Khóa kinh in volume seven of Lục Nhâm đại toàn^[1].

What are the other khóa thể beyond the four basic types?

After the first three methods, volume one of Lục Nhâm đại toàn records six more phát dụng methods: dao khắc (no overcoming within the four khóa, so take an upper spirit that overcomes the day stem, or failing that one the day stem overcomes; called Hao Thỉ and Đạn Xạ), mão tinh (no overcoming and no dao khắc, take the spirit by the position of Dậu), biệt trách (only three distinct khóa, no overcoming), bát chuyên (can and chi in the same place, only two khóa, no overcoming), phục ngâm and phản ngâm^[1]. The book's list of khóa thể numbers Nguyên Thủ one, Trùng Thẩm two, Tri Nhất three, Thiệp Hại four, Dao Khắc five, Mão Tinh six, Biệt Trách seven, Bát Chuyên eight, Phục Ngâm nine, Phản Ngâm ten, then Tam Quang, Tam Dương and the rest, sixty-four in all^[1].

Lục Nhâm trực chỉ (六壬直指) explains all 720 cục (charts) across the sixty days, from Giáp Tý cục one to Quý Hợi cục twelve; each cục records the khóa thể, khóa nghĩa, explanation and judgment, citing the Khóa kinh, Chỉ chưởng phú and Tâm ấn phú^[2]. A cục usually carries several names at once: cục one of the Giáp Tý day reads "课体：伏吟，元胎"^[2].

Bế Khẩu and Tỉnh Lan

Bế Khẩu is the chart in which the last branch of the ten-day week (tuần vĩ) sits on the first (tuần thủ) and initiates, or the tuần thủ rides Huyền Vũ, or the spirit above the tuần thủ position rides Huyền Vũ and initiates: "凡旬尾加旬首，或旬首乘元武，或旬首位上神乘元武发用者，为闭口课"^[1]. The book explains that the head and tail of the week meet like something sealed with no visible mouth; its image text opens with "禁口不语，事迹难明" (mouth shut, no word spoken, traces of the matter hard to see)^[1]. Tỉnh Lan is the name of a phản ngâm chart without overcoming: volume one records "返吟有克亦为用，无克别有井栏名", found only on the six Đinh, Kỷ and Tân days whose branch is Sửu or Mùi; the Lục Nhâm quân trướng phú section of the book calls the way of drawing the truyền in this case the Tỉnh Lan Xạ method (井栏射法)^[1].

How is a Lục Nhâm chart named?

Naming a chart takes four steps. First, place the nguyệt tướng on the hour of the reading to set the heavenly plate. Second, build the four khóa from the can and chi of the day. Third, apply the phát dụng methods to obtain the Sơ truyền: with one overcoming use tặc khắc; with several, tỷ dụng then thiệp hại; with none, dao khắc then mão tinh; with fewer than four distinct khóa, biệt trách or bát chuyên; when the twelve spirits rest in their home positions, phục ngâm, and when the heavenly plate stands opposite the earthly plate, phản ngâm. Fourth, the method used gives the chart its first name, then the shape of the three truyền and the thần sát add further names. The verse of the tặc khắc method states how to take the Trung and Mạt truyền: "初传之上名中次，中上加临是末居" (the spirit above the Sơ truyền is the Trung truyền, the spirit above the Trung truyền is the Mạt truyền)^[1].

Does every chart have a khóa thể?

Yes. Every chart falls under one of the nine phát dụng methods, so it carries at least one name; most carry several more from the shape of the three truyền and the thần sát. For the same day, hour and nguyệt tướng there is only one set of four khóa and three truyền; results can differ only where books record different secondary rules, such as the choice between two Thiệp Hại spirits of equal depth described above.

In what order should these four khóa thể be learned?

Nhật Nguyệt's suggestion: learn them in the order the book checks them: look for a khóa with lower overcoming upper first, then upper overcoming lower, and only then the cases with several overcomings that are settled by tỷ dụng and thiệp hại. Setting up a few charts yourself and comparing the names with Lục Nhâm trực chỉ is a quick check, since that book lists the khóa thể for all 720 cục.