Square

A square is the aspect of ninety degrees, one of the five classical aspects, traditionally counted among the tense or challenging relationships between two bodies. It is one of the four configurations Ptolemy recognised as a true aspect in the Tetrabiblos, the ninety-degree arc being narrow enough that the two bodies plainly behold one another yet share none of the underlying compatibility that softens the trine or the sextile; on his reasoning the elements and qualities governing bodies a quarter of the circle apart are actively opposed, which is why the square carries its difficult reputation rather than a neutral one. The angle corresponds to the fourfold division of the circle and to the interior angle of the square itself, a coincidence of geometry and name that made the aspect easy to picture and to draw from the earliest sources.

As with the trine and the opposition, the square's standing as a genuine aspect, rather than a synodos-like fusion or a mere aversion, was never in question in the ancient sources; the debate over which configurations counted as true aspects concerned the conjunction and the intermediate distances, not this one. The square shares this settled status with the trine, sextile and opposition, and its later reputation for difficulty says nothing about its standing as a genuine aspect; on Ptolemy's own account a square is every bit as much a real relationship between two bodies as a trine, only one governed by qualities and elements that work against each other rather than together.