Ptolemy’s Digression: Astrology’s Aspects and Musical Intervals

The rationale behind aspects has been relatively unexamined in astrology’s tradition, although much development has occurred over the centuries. This article explores a passage in Ptolemy’s Tetrabiblos Book I, Chapter 14. While presenting the different aspect relationships, Ptolemy alludes to musical intervals, in addition to arithmetical relationships. Examining this and similar passages in Ptolemy’s Harmonics and Plato’s Timaeus, this article asserts the importance of specific harmonizing musical intervals to bring together planets, solve the ancient problem of action at a distance, and account for astrology’s aspects.