At a glance
- Identification point
- Circular midpoints require wraparound handling.
Definition and identification
Synastry retains two separate charts and compares positions between them. A midpoint composite produces a third diagram from corresponding points. Other relationship-chart methods use averaged times or places and should be identified separately. A calculated composite is not automatically a real birth event, and its construction differs fundamentally from comparing two original charts.
Structure and reading rules
Cross-chart aspects and house overlays are common comparative procedures; overlays depend on time accuracy and house choices. Midpoint calculations require circular wraparound and a convention for the two opposite midpoints. Historical and modern writers emphasize different relationship questions. Interpretations should identify their framework instead of turning one angular relationship into a fixed label for two people.
Concrete example
Points at three hundred fifty and ten degrees have a midpoint at zero along the shorter arc. An arithmetic mean of one hundred eighty ignores circular wraparound. Comparing the two original points instead gives a twenty-degree separation. These distinct calculations explain methods, without deciding whether fictional people are compatible or revealing another person’s feelings.
Historical context and limits
Ancient marriage discussions document older interpretive habits, not a complete history of modern midpoint composites. The modern method should not be attributed backward to Ptolemy. Real relationships involve actions, values, communication and safety. Both people should consent to use of their data, and chart reading should not make authoritative claims about an absent person’s private intentions.
References & further reading
Historical sources document ideas and rules of their time, not empirical proof of predictive accuracy. Source notes identify the nature and scope of each reference.
- Sepharial, Astrology: How to Make and Read Your Own Horoscope (1920)Primary / tradition source
Modern practitioner manual for chart construction and timing; its scientific and health claims are not endorsed.
- Ptolemy, Tetrabiblos, Book IIIPrimary / tradition source
Ancient natal astrology; editorial notes identify the limited treatment of houses.