Aristotle & Astrology: Part One

Essentiality and Accidentality.

In traditional forms of astrology, the condition of a planet is assessed by calculating its dignity and/or debility. This indicates how well a planet will be able to fulfill its inherent agenda, as well as the quality of that expression.

For example, a highly dignified Mars will more powerfully assert himself in the chart and will likely bring about his more positive significations (bravery, courage, valor, etc.); as opposed to a debilitated Mars, who will have less overall influence and will be more likely to express negative significations (violence, aggression, anger, etc.).

There are two types of dignity and debility – essential and accidental.

Essential dignity and debility is assessed by observing where the planets finds themselves – their position on the wheel of the zodiac. The astrologer will note if the planet is in their own domicile (the sign they rule), exaltation, triplicity, term (bound) or face (decan). A planet with good zodiacal placement is said to be essentially dignified. Conversely, a planet in their detriment or fall is said to be essentially debilitated. A planet with no essential dignity or debility is said to be peregrine (a “foreigner”).

Accidental dignity or debility is assessed by observing how the planets find themselves – the overall degree of agency and activity in the chart. The astrologer will note if the planet is angular (within orb of the ASC/DSC & MC/IC axes), in direct motion, visible (unobscured by the Sun’s orb), conjunct or in aspect of benefics and moving at a good speed. A planet meeting these conditions is said to be accidentally dignified. Conversely, a planet who is retrograde, combust or “under the beams” of the Sun, conjunct or in aspect of malefics and moving slowly is said to be accidentally debilitated.

Sometime during the medieval period, a weighted point system was developed that numerically measured the strength of a planet’s dignity and/or debility. We encounter this system in the work of Masha’allah and Ibn Ezra, and developed further in the late Renaissance by William Lilly.

Dignities and debilities from Lilly’s Christian Astrology (1647).

I believe the notion of essential and accidental dignity, particularly in the medieval period, has its roots in Aristotelianism. Aristotle and his later adherents, such as the astrologers of the Islamic Golden Age (8th–14th century CE), made the distinction between essential and accidental properties. Essential properties are those that are integral to the nature of an object; the properties that cannot be subtracted from it without losing its identity. Accidental properties are those that an object could lack while still retaining its identity. This is what has been referred to as the basic modal characterization, which explains the notion in terms of necessity versus possibility – what properties an object must possess (necessity) and what properties it can possess (possibility).

For example, in order for an object to be classified as a football, it must be a prolate spheroid consisting of an inflated rubber bladder surrounded by a hide-like material and bound by laces. In the absence of any of these properties, the object ceases to be a football. These are the essential properties of a football.

Footballs are usually brown in color; they often have two white circles on their conical extremes and are usually marked with a brand name, such as “Wilson.” These properties may be omitted, however, without negating the identity of the object. If one were to encounter, say, a red football without circles or a brand name yet still retaining the essential properties, one would still recognize the object as being a football. The properties the object could lack while retaining its identity are called accidental.

The notions of essentiality and accidentality may also be applied to the significations of the planets, signs and houses. What, for example, are the essential and accidental properties of Venus in Scorpio on the 6th house?

The application of this distinction – this basic modal characterization – lends itself to clear and orderly thought and may allow the astrologer to glean more precise information from the placements of planets in signs and houses.