Geomantia · the shield chart
Western geomancy
Sixteen figures made of dots, four of them drawn and eleven derived, by rules that have not changed since they arrived in Europe from Arabic sources in the twelfth century. For four hundred years this was one of the most widely practised forms of divination in the West, and it is the most purely algorithmic thing on this site.
Four Mothers from four rows of marks made too fast to count, then eleven more figures derived from them by rules that have not changed since the twelfth century. The randomness is your browser’s cryptographic source, not your birth date.
The one thing you can check
The Judge can only ever be one of eight figures: Via, Fortuna Minor, Amissio, Carcer, Conjunctio, Acquisitio, Fortuna Major, Populus. Not sometimes, not usually. It cannot be Puer or Rubeus or Laetitia however the Mothers fall.
The reason is worth following, because it is the whole structure in one line. Unwind the shield and the Judge turns out to be every Mother added to every Daughter. The Daughters are the Mothers transposed, so between the two halves each of the sixteen dots in the four Mothers gets counted exactly twice, and anything counted twice cancels in parity arithmetic. The Judge comes out even every time. We check that against all 65,536 possible sets of Mothers rather than by casting a few thousand and hoping.
It is also a test you can run on any other geomancy calculator you find. Cast it until it gives you an odd Judge. If it does, it is not doing the arithmetic.
- The Judge
- The Judge must be one of the eight figures with an even number of single dots. Unwound, it is every Mother added to every Daughter, and the Daughters are the Mothers transposed, so each dot is counted twice and the parity cancels. An odd Judge is arithmetically impossible rather than merely rare, and the test checks all 65,536 possible sets of Mothers
- Randomness
- crypto.getRandomValues, the same source the I Ching casting uses, never anything derived from your birth details. Traditionally the four Mothers came from marks made too fast to count, and an uncontrollable count is the point
- Elements
- Each figure takes the element of its ruling sign, so the attribution is derivable rather than a second tradition to take on trust
- The houses
- The twelve houses of the shield chart are not computed here. Distributing the figures into houses needs a querent, a question and a house system, and the several methods in circulation disagree, so this gives the shield and stops
The sixteen figures
Four lines, each one dot or two, which makes sixteen and no more. Four of them read the same upside down and the other twelve pair off into opposites, which is a structure you can verify by looking rather than something to take on trust.
| Figure | Lines | Rules | Read as |
|---|---|---|---|
| Via The way | Moon Cancer · Water | A road: four single dots in a line. Change, journeys, and things going somewhere else. Good for movement, poor for anything you wanted to stay where it was. | |
| Cauda Draconis Tail of the dragon | South node Sagittarius · Fire | An exit. Good for endings and bad for beginnings, and the figure the old texts least want to see at the start of anything. | |
| Puer The boy | Mars Aries · Fire | A young man with a sword. Energy without judgement: useful in a contest or a fight, and a liability nearly everywhere else. | |
| Fortuna Minor Lesser fortune | Sun Leo · Fire | Outward help. Success that arrives quickly and by somebody else's hand, which is also the whole of its limit. | |
| Puella The girl | Venus Libra · Air | Harmony and attraction. Favourable in almost everything and unreliable in exactly one thing, which is a promise. | |
| Amissio Loss | Venus Taurus · Earth | Loss, and specifically of something held. Bad for keeping and good for getting rid of, which is not the same as simply bad. | |
| Carcer The prison | Saturn Capricorn · Earth | Binding. Delay, restriction, being stuck, and occasionally a wall that is doing you a favour by standing there. | |
| Laetitia Joy | Jupiter Pisces · Water | Gladness, health and building. One of the two best figures, and the one most associated with things that last. | |
| Caput Draconis Head of the dragon | North node Virgo · Earth | An entrance. Good for beginnings and poor for endings, the exact mirror of its own tail, which is also its mirror on the page. | |
| Conjunctio Conjunction | Mercury Virgo · Earth | Meeting. Neutral in itself and takes its colour from whatever it meets: it joins what is already happening rather than starting anything. | |
| Acquisitio Gain | Jupiter Sagittarius · Fire | Getting and keeping. The best figure for money in the tradition, and the one that most rewards waiting. | |
| Rubeus Red | Mars Scorpio · Water | Passion, anger and appetite. The classical texts advise treating a chart with Rubeus in the first house as unfit to be read at all, which is the only such instruction in the system. | |
| Albus White | Mercury Gemini · Air | Cool clarity. Good for judgement, thought and peace, and slow in anything that wants force. | |
| Tristitia Sorrow | Saturn Aquarius · Air | Downward. Grief, and also depth and what only comes from staying with something unpleasant. Traditionally good for anything underground. | |
| Fortuna Major Greater fortune | Sun Leo · Fire | Inward strength. Success that comes from your own power and therefore holds, which is what makes it the greater of the two fortunes. | |
| Populus The people | Moon Cancer · Water | A crowd: eight dots and no single anywhere. Empty in itself and takes on whatever stands next to it, so it is read as the mood of a situation rather than a force in it. |
AsterNym explores these as cultural and metaphysical traditions, not scientific predictions.