The Five Major Aspects
Conjunction, sextile, square, trine, and opposition: the classical aspect set, its approximate angles, the traditional readings attached to each, and why orb conventions differ between schools.
HellenisticRenaissance & early modernModern WesternTraditional doctrineEditorial synthesis
In this lesson
- Name the five classical aspects and their approximate angular definitions
- Summarise, in interpretive register, the traditional character assigned to each
- Explain what an orb is and why orb conventions differ between schools
- Note the classical nuance that the conjunction is co-presence rather than an 'aspect' strictly speaking
Before this lesson: What Is an Aspect?
The classical repertoire recognises five major configurations, defined by the equal divisions of the circle. The angles below are their ideal geometric definitions; in a real chart, positions come from computation, and closeness to the ideal angle is a separate question handled at the end of this lesson.[1][2]
- Conjunction: about 0°: two planets together in the same place. Traditionally read as a fusion of the planets' significations, taking its tone from the planets involved.[3]
- Sextile: about 60° (a sixth of the circle): traditionally read as an easy, cooperative connection, milder than the trine.[3]
- Square: about 90° (a quarter): traditionally read as friction and productive tension between the planets' agendas.[3]
- Trine: about 120° (a third): traditionally read as harmony and easy flow, classically linked to signs of the same element.[3][2]
- Opposition: about 180° (a half): planets facing each other across the circle, traditionally read as polarity, confrontation, or balance sought between two pulls.[3]
Character is doctrine, not measurement
Notice the register of every description above: 'traditionally read as'. The angles are geometry; the easy/hard character of trines and squares is doctrine transmitted from the classical sources through manuals like Lilly's into modern practice. No study is claimed here, and traditions also insist the planets involved matter more than the bare angle.[1][3]
Orbs: how close counts?
Real charts rarely serve up exact angles, so every school needs a tolerance: the orb. And orb conventions genuinely differ: older practice, following authors like Lilly, attached orbs to the planets (each planet casting an 'influence' of some width), while most modern practice attaches orbs to the aspects (say, a wider allowance for a conjunction than for a sextile), with schools and software disagreeing on the numbers. Sign-based reckoning sidesteps degrees entirely.[3][2]
In brief
The five majors divide the circle evenly: conjunction (~0°), sextile (~60°), square (~90°), trine (~120°), opposition (~180°). Their easy/hard characters are traditional doctrine, not measurements; classically the conjunction is co-presence rather than a true aspect; and how close an angle must be to count (the orb) is a convention that differs between schools and must be stated by any honest tool.
Check your understanding
Check your understanding:
- Which equal division of the circle produces each of the five major aspects?
- What is an orb, and name two different ways schools have defined orbs.
- Why can two astrologers disagree about whether a given pair of planets 'is' in square without either making an arithmetic error?
References
Numbered citations in the text link to the records below; each record links to the full source registry.
- Claudius Ptolemy. Ptolemy's Tetrabiblos, or Quadripartite: Being Four Books of the Influence of the Stars. J. M. Ashmand (translator). W. Foulsham & Co. Ltd, London. 1900. Historical primary source View source record
- Chris Brennan. Hellenistic Astrology: The Study of Fate and Fortune. Amor Fati Publications. 2017. Modern practitioner interpretation View source record
- William Lilly. Christian Astrology, Modestly Treated of in Three Books. T. Brudenell for J. Partridge & H. Blunden, London. 1647. Historical primary source View source record