Decumbiture

Definition

A decumbiture is a specialized horary chart cast for the moment a patient takes to their bed at the start of an illness. The Latin decumbere, "to lie down," gives the technique its name, and the chart serves as a tool for diagnosis and for prognosis — judging how the illness will run — when the patient's birth chart is unknown or unreliable. Holden defines a decumbiture as "a horary chart set for the time someone took to bed because of illness," from which the astrologer "could make a diagnosis and prognosis of the illness."

In Tradition

In medieval and Renaissance medical astrology, the decumbiture is read as a horary chart focused on health: the first house stands for the patient, the sixth for the disease, the seventh for the physician, the tenth for the medicine, and the fourth for the outcome. The Moon, as the chief lunar significator of the body, is tracked through its quarterly phases — the "critical days" — to anticipate turns in the illness, its approaching aspects to difficult or helpful planets weighting the prognosis.

In Practice

The astrologer casts the chart for the exact moment the patient took to bed. The Moon's position, its approaching aspects, and its progress through its quarters from that moment set the timeline of "critical days" — traditionally the 7th, 14th, 20th, and 28th days, read as turning points in the disease. The Lord of the Ascendant stands for the patient's strength; the Lord of the sixth for the disease itself. Aspects between these significators, the condition of the Moon, and any malefics — difficult planets — sitting in the angles or in the sixth or eighth house all carry prognostic weight. A decumbiture is consulted both at the onset of illness and at a relapse, and it is treated as binding for that specific episode rather than for general health. The technique was central to medieval and early-modern medicine and survives in the 20th-century traditional revival.

Historical Origin

Decumbiture practice descends from Hippocratic and Galenic medical astrology, is preserved in the Arabic-Latin transmission through Sahl and Bonatti, and is most famously codified in English in Nicholas Culpeper's Astrological Judgement of Diseases from the Decumbiture of the Sick (1655) and in William Lilly's Christian Astrology (1647). Holden's History of Horoscopic Astrology documents the technique's continuous use from antiquity into Renaissance medical practice.

Etymology

Origin: Latin. Meaning: From decumbere, "to lie down" (de- "down" + cumbere "to lie"), via medieval Latin decumbitura, "a taking to bed.".

Further Reading