The Part of Fortune
The Part of Fortune — Pars Fortunae in the older texts — is not a celestial body but a calculated point. It arises from the relation between the Sun, the Moon and the ascendant, and it is among the very oldest elements of astrology.
The calculation
The formula is simple, and it runs one way by day and another by night:
- Day birth (Sun above the horizon): ascendant + Moon − Sun
- Night birth (Sun below the horizon): ascendant + Sun − Moon
The arithmetic is done in degrees of longitude counted from zero degrees of Aries. That the formula is reversed is no detail: it follows the doctrine of sect, by which the Sun rules day births and the Moon rules night births. Many modern programs calculate the day formula only — for a night birth the point simply ends up in the wrong place.
What it shows
The Part of Fortune describes where in life something comes in easily — the bodily, the material, the tangible. The old texts connect it with the body, with property, and with what falls to one, so to speak, as opposed to what one works for.
It is read like a sensitive point, not like a planet:
- the house it stands in — the area of life in which this shows;
- the ruler of the sign it stands in — whose condition decides whether anything comes of it;
- planets in aspect to it, the conjunction working by far the most strongly.
The ruler matters more here than the point itself. A well-placed Part of Fortune whose ruler is weak and in fall promises more than it delivers.
The other points
The Part of Fortune is only the best known of many. The Hellenistic and Arabic traditions know dozens — points of the spirit, of the father, of marriage, of illness — all formed on the same pattern out of three factors.
Most have disappeared from practice, and for an understandable reason: anyone who calculates enough points will always find one that seems to confirm something. Anyone working with them should settle in advance which ones to use, and not start looking only when the chart yields nothing else.
What it is not
No promise of good fortune. The name is a translation of Fortuna and means what chance brings, not what is good. A Part of Fortune in a difficult position describes exactly the same area of life — only with what goes wrong there.
See also: the planets and the ascendant, without which the point cannot be calculated.