Quincunx

A quincunx, also called the inconjunct, is the aspect of one hundred and fifty degrees. In classical doctrine the signs standing at this distance were in aversion, meaning they did not behold one another at all, sharing no element, mode or polarity in common, and Ptolemy's four true aspects excluded the relation for exactly the reason they excluded the conjunction, on the opposite side: where the conjunction's two bodies were too close to be seen as separate, the quincunx's two bodies were too far out of alignment to be seen as related. Its use as an active minor aspect came later, when astrologers working after Johannes Kepler's reworking of aspect doctrine in the early seventeenth century began reading angles the Ptolemaic scheme had ignored, and modern practice largely inverts the ancient judgment, treating the original incompatibility not as a reason to exclude the angle but as its meaning: two functions with nothing obviously in common that are nonetheless required to work together, producing the adjustment and low-grade friction the aspect is generally said to describe.

Because five signs is an awkward, non-repeating distance around the twelvefold zodiac, a quincunx always joins bodies with nothing in common by sign, mode or element, which is precisely the geometric fact that made Hellenistic astrologers call the relation an aversion in the first place and that modern practice has simply relabelled as its meaning rather than its disqualification.