At a glance
- Identification point
- Longitude differences require circular wraparound.
Definition and identification
An aspect usually compares two ecliptic longitudes using the smaller separation from zero to one hundred eighty degrees. Familiar reference angles are conjunction, sextile, square, trine and opposition. This is a projected angular relationship, not necessarily physical proximity in space. The geometry alone does not establish whether an event is fortunate or difficult.
Structure and reading rules
Degree-based systems normally specify an orb, a permitted deviation from an exact reference angle. Some older systems first classify relationships between entire signs. Applying and separating aspects additionally depend on direction and speed. Two points close to an exact angle in a static chart do not by themselves reveal whether their separation is increasing or decreasing.
Concrete example
Longitudes of ten and one hundred two degrees differ by ninety-two degrees, two degrees from an exact square. Under a six-degree orb that meets the selected rule. Longitudes of three hundred fifty and ten degrees have a smaller separation of twenty, not three hundred forty. This arithmetic checks wraparound without involving a real person.
Historical context and limits
Ptolemy connects selected relationships with zodiac geometry and proportional reasoning. Modern additions such as quintiles or quincunxes need their own system attribution. Harmony and tension are interpretive metaphors, not diagnoses or causal measurements. Different readers can interpret an identical angle differently; reproducible calculation does not substitute for testing predictive effectiveness.
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.
- Ptolemy, Tetrabiblos, Book IPrimary / tradition source
Primary evidence for Ptolemy’s classifications and aspects, not modern evidence for efficacy.
- 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.