Origen
Where it comes from
Synastry (from the Greek syn-astron, "stars together") is one of the most ancient uses of astrology. Ptolemy already described it in the Tetrabiblos in the 2nd century. Vedic astrology has worked for millennia with kuta to evaluate compatibility before marriage. Johannes Kepler, in the 17th century, devoted an entire treatise to it (Harmonices Mundi). The idea is simple: if a single chart describes a person, two superimposed charts describe the field created between two.
