Prohibition

The fuller picture

The image the older authorities use is a person standing between the querent and the thing sought after, and it describes the mechanism well. An aspect between the two significators was going to perfect, and a third planet intervenes first. That establishes the interruption shape; whether the promise is actually cut off still depends on what that planet signifies and whether it has power to act.

It happens in two shapes. In the first, the applicant diverts: the faster significator is closing on the slower one, and before that aspect completes it perfects an aspect to some other planet instead. In the second, an outsider arrives first: one significator is applying to the other, and a third planet — faster than the applicant — reaches the target before it can.

That second shape is a hair's breadth from translation of light, and the difference decides the verdict. In a translation, the third planet has already been in aspect with the first significator and is carrying something from it. In a prohibition it hasn't; it simply gets there first. Same three planets, one step of geometry apart, and the reading inverts from being helped by a go-between to being beaten to it by a stranger. So before calling anything a prohibition, check whether the interloper has a prior separation behind it.

The prohibitor is identifiable, which is what makes this useful rather than merely discouraging. Read the house the prohibiting planet rules and you have the person or the thing that got in the way. The worked case is a promotion question where the person asking applies to the thing asked about by trine, and the ruler of the twelfth perfects its conjunction to the same planet first: a hidden enemy who wanted the same job and got there first.

Here's the part that will save you a wrong answer. A prohibiting planet that signifies the same outcome as the aspect it interrupts does not prohibit anything. In a fertility question the Moon's sextile to the ruler of the fifth arrives before her conjunction to the ruler of the first — geometrically a textbook interruption, and useless as one, because in that question both contacts mean children. Check what the intervening planet means before you treat it as an obstruction.

There is a structural reason to take a genuinely harmful prohibition seriously rather than reading past it. Once an aspect between two planets is cut off by a powerful third planet that is destructive to this matter, you don't push through to a later, more agreeable aspect further down the line. But the earlier contact is only the geometry: a helpful interposer can assist, and a neutral one can describe the place or circumstance in which the parties meet.

Finally, keep it apart from frustration, which is the neighbouring failure and the one it gets confused with. In prohibition either the applicant is diverted or an outsider overtakes it. In frustration the target itself moves on to something else. Both look the same from a distance — two applying aspects sharing a planet, the faster one perfecting first — and the house you read for the cause is different in each.