astrology-traditions/0.1 · released 2026-08-16
Astrology traditions
Astrology is not recorded here as one body of knowledge. It is recorded as named interpretive traditions, each with its own sources, techniques, and disagreements. Every rule declares the tradition it belongs to, because a rule detached from its tradition belongs to none of them.
The epistemic boundary
Every rule in this layer is recorded as unvalidated tradition. That status is fixed in the schema and cannot be raised. This layer claims that a passage has been transcribed accurately from a named source. It does not claim, and cannot express, that any rule predicts anything.
Provenance quality and empirical support are recorded on separate axes precisely so that a rule can be well-sourced and unsupported at the same time. Appearing in a respected old text is a fact about the text, not evidence about the world.
Prohibited uses
These apply to every rule in the registry without exception, and no generated report may produce them.
- medical diagnosis, prognosis, or treatment decisions
- legal conclusions or advice
- investment, trading, or other financial decisions
- predictions of death, disaster, or pregnancy outcomes
- claims that a chart determines personality, capability, or behaviour
- guarantees about future events
- high-stakes decisions taken on astrological grounds alone
- employment, lending, insurance, or housing decisions about a person
Traditions
4 registered · 24 rules
Hellenistic (Ptolemaic)
2nd century CE, transmitted through Arabic and Latin commentary
The system set out in Ptolemy’s Tetrabiblos, which grounds planetary signification in the four elemental qualities and treats the zodiac as measured from the equinox. It is the transmission route for much later Western practice, and it is not identical to any of them.
Horary (Lilly)
17th-century England
The question-based practice codified in William Lilly’s Christian Astrology, which judges a chart cast for the moment a question is understood rather than for a birth.
No rules published: No rights-cleared, proofread transcription of the 1647 text is available. The source is public domain, but every machine transcription found is unproofread OCR; publishing rules from it would violate this layer’s transcription-fidelity claim.
Vedic (Jyotiṣa)
classical Indian, transmitted continuously to present practice
The Indian sidereal system, whose electional branch (muhūrta) judges the fitness of a moment from the five limbs of the pañcāṅga. Its calendrical arithmetic is computed in `lib/panchanga.ts` and is fully reproducible; the judgements built on that arithmetic are recorded here, sourced to Varāhamihira.
Western sidereal
20th century onward
Western practice that measures the zodiac against the fixed stars rather than the equinox. Registered here to make the frame disagreement explicit: a sidereal rule and a tropical rule that use the same sign name do not refer to the same region of sky.
No rules published: Primary sources for this tradition are 20th-century and in copyright. Passage-level excerpting requires a licensing decision that has not been taken.
Sources
Only rights-cleared editions may carry excerpts. Passages are transcribed verbatim and bounded; where an edition differs from others, the difference is recorded rather than silently corrected.
- Ptolemy’s Tetrabiblos, or Quadripartite · Claudius Ptolemy, tr. J. M. Ashmand · composed circa 2nd century CE · Project Gutenberg eBook #70850, from the 1822 Ashmand translation
public-domain — The 1822 Ashmand translation is out of copyright, and the Project Gutenberg transcription is distributed without restriction in the United States.
- The Bṛhat Saṃhitā of Varāha Mihira · Varāhamihira, tr. N. Chidambaram Iyer · composed circa 6th century CE · 1884 English translation, proofread transcription published by wisdomlib.org
public-domain — The 1884 Chidambaram Iyer translation is out of copyright. Transcribed from the proofread wisdomlib presentation rather than the Internet Archive scan, whose OCR renders the English as Devanagari mojibake and is unusable for verbatim quotation.
- Christian Astrology · William Lilly · composed 1647 · Internet Archive scans of the 1647 and 1659 printings
public-domain — The 1647 text is out of copyright. No passages are transcribed here: the available machine transcriptions are unproofread OCR of 17th-century typography, and quoting them would introduce corruption into a layer whose only claim is transcription fidelity.