Zhengyin (正印) — Regular Seal

Zhengyin is the element producing the Day Master of opposite polarity — e.g. 癸 (yin water) producing 甲 (yang wood). It represents formal lineage of support: mother, official teachers, academic credentials, inherited titles, and traditional learning.

Healthy Zhengyin gives natural respect for tradition, scholarly aptitude, comfortable rapport with mother and elders, and the protective wisdom of accumulated knowledge. Excessive Zhengyin can lead to over-dependence on family or rigidity in thought; too weak signals weak grounding or hard relationship with mother figure.

Under the Han, appointment to a post and the handing over of seal and ribbon were one act, and authority existed once the seal was in hand. That is the object the word yin originally named — the seal of office and the silk ribbon that carried it — and where its weight in this vocabulary comes from. The manuals borrowed the image for whatever backs a person up: whatever produces the Day Master is a Seal, and to hold one is to have something to stand on. Zhengyin is production across opposite polarity, close the way a mother raises a child, which is why tradition assigned it the mother, the recognised teacher and inherited standing.

A Regular Seal is not a diploma. The classics read it as rank and lineage of teaching because those were the visible forms that credentials took; what it names is the relationship of being supported, recognised and backed, which need not correspond to any certificate. Nor should a heavy Seal be read as high intelligence, since classical verdicts on Seal-heavy charts tend toward careful thought and slow action, strength in consolidating and absorbing more than in initiating. And while the Regular Seal is assigned to the mother, kinship assignments in this system are symbolic correspondences; the older writers themselves warned against judging a family relationship from a single character.

Judging a Regular Seal begins with whether the Day Master needs one. A weak self with a rooted Seal is read as properly supported: backing to draw on, a settled temperament. A self already strong under a heavy Seal is read as over-nourished, described as a mother so indulgent the child cannot stand alone, which comes out as dependence and hesitancy. Then check whether the Seal is damaged: Wealth conquers the Seal, and heavy Wealth over a light Seal reads as practical pressure overriding learning and protection. By position, the year pillar points to family shelter and early schooling, the month to career and mentorship, the day branch to domestic support.

The pairing classical practice admires most is Regular Seal with Zhengguan (正官 zhèngguān, Regular Officer). The Officer supplies position and constraint, the Seal supplies credentials and cover, and an unobstructed chain from Officer to Seal to Day Master was taken as the source of standing, echoing an institutional fact: office and seal were issued together. With Wealth the relation reverses. Wealth conquers the Seal, and the old figure of greed for wealth spoiling the Seal describes learning and reputation eroded by immediate advantage. Against the output stars the contrast is direction: Seal gathers inward, Shishen (食神 shíshén) and Shanguan (傷官 shāngguān) push outward, and the balance between them often decides the temperament of a whole chart.

Most of the disagreement concerns Seal-heavy charts. One camp holds to the over-nourishment doctrine: an excessive Seal must be reduced by a Wealth star before the Day Master will act. Another asks whether the self has an outlet, since with output stars to drain it or Officer stars to carry, a heavy Seal becomes accumulated depth instead of a burden. Women's charts diverge too: older manuals read the Seal as mother and domestic merit, framing such a chart around family, a framing of its period, while later readings treat it as a need for security and knowledge. Whether the two Seals should be judged separately is unsettled.

During a Seal luck period, classical method asks not how strong the Seal is but whether the Day Master currently lacks one. A weak self entering a Seal period is usually read as gaining support, with progress in study and standing; a strong self entering the same period is more often read as opportunity multiplying while the impulse to act falls away. Seal periods are also linked to examinations, qualifications and contracts, matters that turn on documentation. That association goes straight back to the original image: secure the seal first, and only then does the position hold.