Combust

Meaning

A planet is combust (Latin combustus, "burnt") when it is so close to the Sun that it is overwhelmed by the Sun's light and heat. It is invisible, lost in the glare, and traditionally unable to act on its own behalf. Combustion is one of the heaviest accidental debilities in the tradition; Lilly calls the combustion of any planet "the greatest misfortune that can be" [4].

Combustion is one of three bands of distance from the Sun:

The orbs vary between authorities:

Al-Bīrūnī's figure for Mars is 16° or 18° (the scan of Wright's translation is unclear at this point), and his figures for the planets' approach to the Sun in the evening differ slightly from those for their departure in the morning [3].

Origin and history

Hellenistic astrologers were concerned above all with whether a planet was visible or hidden by the Sun, and used the broad condition of being under the beams (roughly 15°). Dorotheus says that a planet under the Sun's rays loses its power [1], and that when the lord of the Lot of property is under the rays, what the Lot promises does not last [1]. Paulus Alexandrinus says that planets within 15° of the Sun make a morning or evening setting, that is, they disappear, and that within 9° they are even more ineffectual [2]. This inner band is close to what later writers call combustion.

The separate, narrower category of combustion is clearly defined by astrologers writing in Arabic, who called it iḥtirāq, "burning"; a combust planet is muḥtariq [3]. Al-Bīrūnī defines it as being beyond the cazimi minutes but within 6° of the Sun, after which the planet is merely under the rays, "like a prisoner in confinement", until it is far enough away to begin to appear [3]. He adds that a planet separating from the Sun is like a sick person recovering [3], and that Venus at a high northern latitude remains visible and so should not be called combust at all [3].

Lilly's definition is the one most used in English. A planet is combust when it is in the same sign as the Sun and within 8°30′ of it, before or after [4]. He explains the figure: he allows half of the Sun's own orb (17°), not half of the planet's, and notes that by the other rule Jupiter would not be combust until within 4½° of the Sun, adding that many disagree with him [4]. He also says:

• a planet is more afflicted when the Sun is approaching it than when the Sun is moving away [4];
• combustion is only by bodily conjunction, never by aspect: a square or opposition of the Sun afflicts but does not combust [4];
• a combust significator of the querent shows the person in great fear and overpowered by someone greater [4];
• if the lord of the Ascendant is combust, the question will not come to anything [4].

How it is used

Points on this site. A planet within 8° of the Sun (but not within 17′) scores −5, the same as Lilly's value [4]. The site uses a round 8° rather than Lilly's 8°30′, measures distance in longitude only, and does not apply Lilly's same-sign condition. It does not score the Moon for combustion.

Same sign or not. Lilly required the planet and Sun to be in the same sign [4]. Many astrologers, before and since, have measured combustion by orb alone, across sign boundaries. Lilly's own example judgements also speak of a planet "entering combustion" as the Sun approaches it, treating the condition as something that builds up rather than switching on at an exact line [4]. This is one of the details worth checking in any author's usage.

Applying and separating. Following Lilly and al-Bīrūnī [3][4], many practitioners treat a planet the Sun is approaching (the planet moving into combustion) as worse off than one separating from the Sun. In horary, a significator going to combustion can show someone about to be overwhelmed or exposed; one leaving it, someone recovering [4].

The Moon. Whether the Moon can be combust is disputed. Al-Bīrūnī says the Moon is cazimi and combust in the same way as the other planets, and then under the rays until about 12° from the Sun, when the new crescent can appear [3]. Lilly clearly treats the Moon as combustible: in a question about a ship at sea, the Moon combust is one of the signs that the ship is lost [4]. Many modern practitioners treat the Moon near the Sun as a separate matter, the dark or new Moon, and do not score it as combust. This site leaves it out.

Via combusta. A separate doctrine, the "combust way" (via combusta), applies only to the Moon: Lilly warns against judging a question when the Moon is in the last 15° of Libra or the first 15° of Scorpio [4]. It is related in name only; it has nothing to do with the Sun's distance.

Combust and retrograde. Mercury and Venus are often combust at the same time as they are retrograde, because their retrograde period is centred on their inferior conjunction with the Sun. The superior planets are never combust while retrograde, because they are retrograde when opposite the Sun.

Examples

• Mars at 12° Gemini with the Sun at 18° Gemini: 6° apart in the same sign, combust (−5 here and in Lilly).
• Mercury at 28° Taurus with the Sun at 3° Gemini: 5° apart but in different signs. Combust on this site (−5); by Lilly's same-sign rule, under the beams instead.
• Jupiter 8°15′ from the Sun: combust for Lilly (within 8°30′), under the beams on this site (beyond 8°), −4.
• Venus 3° from the Sun at inferior conjunction, retrograde, with a latitude of 8° north: combust −5 and retrograde −5 on this site, but by al-Bīrūnī's rule simply "with the Sun" and not combust [3].

See also

For the band just outside combustion, see under the beams; for the exception at the Sun's centre, see cazimi.