A midpoint is a mathematical point halfway between two stellar bodies that tells an interpretative picture for the individual. There are two types of midpoints: direct and indirect. A direct midpoint occurs when a stellar body makes an aspect to the midpoint of two other stellar bodies with an actual physical body at the halfway point. In other words, a direct midpoint means that there is actually a stellar body in the natal chart lying in the midpoint of two other stellar bodies. An indirect midpoint occurs when a stellar body makes an aspect to the midpoint of two other stellar bodies without a physical body at this midpoint.
Midpoints were first used by Guido Bonati (1123–1300) to refine timings in an event chart. However, midpoints were used to calculate Arabian Points, like part of fortune even as far back as 300 b.c. Alfred Witte was the first person to do a lot of investigation on midpoints using movable dials and together with Ludwig Rudolph and Herman Lefeldt formed the Hamburg School of Astrology and the technique was called the Uranian Astrology. Then, Reinhold Ebertin in his book Combination of Stellar influences included psychological principles and simplified the midpoint technique used by the hamburg school. These were further popularized by American authors Aren Ober (formerly Savalan) and Eleanor Kimmel.
- Aren Ober: Midpoint Interpretation Simplified, 2nd edition. Cotter Books, Cleveland Ohio, 2009. ISBN 978-0-9794129-0-5
- Alfred Witte & Friedrich Sieggrün: Immerwährende Ephemeride, Witte-Verlag, Hamburg 1935.
- Ebertin, Reinhold: Combination of Stellar Influences, Ebertin-Verlag, Aalen, 1972. ISBN 0-86690-087-X