A dispositor is the planet which rules the sign that any other planet is in. For instance, if Mercury is in Libra, the dispositor of Mercury is Venus, since Venus rules Libra. To figure dispositors, you need to know which planets rule which signs. Here is a list:
Aries is ruled by Mars
Taurus is ruled by Venus
Gemini is ruled by Mercury
Cancer is ruled by the Moon
Leo is ruled by the Sun
Virgo is ruled by Mercury
Libra is ruled by Venus
Scorpio is ruled by Mars
Sagittarius is ruled by Jupiter
Capricorn is ruled by Saturn
Aquarius is ruled by Saturn
Pisces is ruled by Jupiter
The only planet which doesn’t have a dispositor is the one that is in its ruling sign. In this case we might say that it disposits itself, which is true, but not the term commonly used in astrology. Instead we simply say that the planet is in its ruling sign.
Any planet in its ruling sign is doubled in power by its placement – this is what the Greek astrologer Ptolemy said in his classic work “Tetrabiblos,” an ancient text on astrology. Think of the sole dispositor – which is always in its ruling sign – as magnifying the power of a planet even more.
At times we find the case where a planet, say Mercury, is in Libra, which is disposited by Venus, and Venus will be in Virgo, which is disposited by Mercury. In other words, Mercury and Venus in this instance disposit each other. When such a thing happens, the two planets are said to be in mutual reception, and when this condition exists, there is no sole dispositor of the chart. My chart has this, for I have Venus in Cancer and Moon in Libra.
At other times we might find three planets that disposit each other in turn, such as Jupiter in Capricorn, Saturn in Virgo, and Mercury in Sagittarius. In this case, Jupiter is disposited by Saturn which is disposited by Mercury which is disposited by Jupiter. There is no technical term for this setup – but we might simply call it a rulership loop. There are seven traditional planets, and we can have in a chart, conceivably a situation in which a full six of them might be included in one of these rulership loops with the seventh one left out. In this case, there is no sole dispositor because:
The sole dispositor of a chart is a planet in its ruling sign that all the rest of the planets in that chart can be traced back to, when we look at the rulers of the signs they are in.
In doing this, note that we ignore Uranus, Neptune, Pluto and Chiron, because even though some modern astrologers think of them as ruling particular signs, when considering whether or not a chart has a sole dispositor we are only concerned with the TRADITIONAL RULES OF THE SIGNS.
It is also not possible to have a sole dispositor if we have more than one planet in its ruling sign.
The sole dispositor of a chart represents a planet whose energy affects all others, and so an energy that, rather then tending to manifest in certain situations, tends to color through its energy all situations, endeavors and impulses of the person.
The SUN as sole dispositor (it will always be in Leo), signifies a person who approaches life in a purposeful manner, at worst in an egotistical and self-important manner. At best it’s a person who can always bring what is most important in a situation to light, and who proceed always with a self-confidence which instills trust and admiration in others without seeming arrogant or grandiose.
The Moon as sole dispositor (it will always be in Cancer) signifies a person who approaches life emotionally and subjectively. At worst there may be a constant wavering due to their actions being strongly influenced by feelings. This might make them undependable. At best they approach life intimately, always with a feeling of emotional kinship with whoever they come in contact with. They have about them an aura of always nurturing other people.
Mercury as sole dispositor (it will be in Gemini or Virgo) signifies a person who is curious about everything, and thinks about everything, or maybe thinks all the time, and always wants as many of the facts about a situation as can be obtained. When this sole dispositor is in Gemini there is an edge of cleverness and aliveness in everything they do. If the dispositor is in Virgo the person is thorough, perfectionistic, and attends to the details of everything he or she touches. They may also be constantly critical about everything.
Venus as sole dispositor (it will be in Taurus or Libra) signifies a person who is artful in everything he or she does, wanting to bring a sense of beauty and excellence to all endeavors. The person may be a natural peacemaker – especially when the sole dispositor is in Libra. At worst this individual could be selfish or greedy or lazy – the negative manifestations of Venus.
Mars as sole dispositor (it will always be in Aries or Scorpio) signifies a person who is aggressive in everything they do. They approach life with a lot of energy and autonomy, and have a great urge to both create and destroy – for instance they might enjoy clearing a field, or tearing down a house that is no longer needed. There is an edge of aggressiveness about everything they do.
Jupiter as sole dispositor (it will be in Sagittarius or Pisces) signifies a person who is enthusiastic, positively motivated, and tends to always have an optimistic attitude. They think in big terms, possibly too much so, to the extent that they might fail through taking on too much. They always have to beware of going too far, saying too much, etc.
Saturn as sole dispositor (it will be in Capricorn or Aquarius) signifies a person who is very serious, who may take a long time to do things or to develop. Also a person who can be very organized or structured. They may have difficulty having fun, and childhood might be a lot more uncomfortable for them than it is for most people. They might tend to seek out people who are older and wiser from them to learn from. They can be very persevering in what they do, and may tend to be happier with a simple life than one in which they have too many things to do.
The sole dispositor is an important consideration, and should always be taken into account when interpreting ALL OTHER AREAS OF THE CHART, for like a drop of colored ink placed in water, it colors everything.