By Dorian Grimault, astrologer · Published · updated
The square aspect links two bodies a quarter of the circle apart, 90°. It is reputed to be the difficult aspect par excellence, and it is often what gives a birth chart its relief: where two functions collide, something has to move. Here is what Ptolemy and William Lilly say about it, the tolerance AstralPro gives it, and the squares that structure the chart of Camille Morel, AstralPro's sample chart (fictional data).
In the Tetrabiblos (book I, chapter 13), Ptolemy defines the square as the interval of three signs, 90°, a right angle. He gives a musical reason for it: the square is half the opposition, and its ratio to the sextile is sesquialter, 3 to 2, as 90° is to 60°.
Together with the opposition, he ranks it among the disharmonious aspects, because it joins signs of opposite kinds, one masculine and one feminine. A square does join two signs of the same modality, but of two different elements: Aries and Cancer, Fire and Water, both cardinal.
William Lilly, in Christian Astrology (1647, book I, chapter XIX), calls the square a quadrangular or tetragonal aspect, and makes it a sign of imperfect enmity. The opposition, for its part, is perfect hatred. His example comes from horary astrology: two adversaries whose significators are in square may still be reconciled, since the matter has not gone too far, provided other planets help a little.
The nuance is valuable for natal reading: the square is a tension that leaves a way out. It is not a wall but a friction that calls for a response.
Reading a square means identifying the two functions at stake and understanding why they thwart each other. Each carries a need, and the square says that these two needs regularly compete. The question to ask: what rubs when these two energies want to express themselves at the same time? The legend of the aspect table in your report sums it up in one word: friction.
The direction adds a nuance of timing. An applying square describes a tension that is building, one you learn to handle with experience; a separating square, a friction already knotted, which plays out almost by reflex.
With the Sun square the Moon, the will to stand out and the need for emotional security pull in opposite directions. This resistance also produces energy: the square often lies behind strong motivations and the areas where people outdo themselves, once the two forces work together rather than against each other.
In your birth chart and in the Book, the orb of the square is 7°: two bodies 83° to 97° apart are in square. That is one degree less than the conjunction, the opposition and the trine (8°), and one more than the sextile (6°). The tolerance is the same for all bodies, Sun and Moon included.
In the aspect grid, the name of the square is shown in orange, and each line gives the orb in degrees and minutes, then the direction: Applying, Separating or Exact. The wheel draws a square only at 4° or less. The solar return and the compatibility table use 6°, and so does the Book when it looks for a T-square or a grand cross.
For Camille Morel, AstralPro's sample chart (fictional data), Saturn, alone in Aquarius at 23°53', in the 3rd house, stands at right angles to her Scorpio stellium. Aquarius and Scorpio are both fixed signs, and her grid counts three squares to Saturn, all of them discussed:
All three are drawn on the wheel, under the 4° threshold. Moon square Saturn shows a subtlety: although a chapter discusses it, it still carries a dash in the Reading column, which is reserved for lines up to 3° of orb.
Camille's Midheaven, at 0°15' Virgo, alone receives four squares from Sagittarius and Scorpio: the North Node (2°45'), the Moon (3°06'), Mars (3°23') and Pluto (4°58'). Since an angle is involved, their Direction column carries a dash. The Mars-Midheaven square opens the Vitality & pace of life section, and the North Node-Midheaven square the Where you are heading section.
The wheel draws only two of them, those of the Moon and Mars: the North Node is not connected in the drawing, and Pluto's square exceeds 4°.
Other squares live outside the grid. Among the close contacts of the celestial points, there is Pholus square Mars, orb 0°11'. And the Karmic Chart chapter notes Chiron square the axis of the Nodes, orb 4°52'.
Ptolemy counts squares in signs: three signs apart, two signs of the same modality. AstralPro counts in degrees, and a square can then join signs that are not three signs apart. Camille's chart gives two examples. The Moon, at 27°09' Scorpio, is 86°54' from the Midheaven, at 0°15' Virgo: a square with a 3°06' orb. Pluto, at 25°17' Scorpio, is 4°58' from the square to the same Midheaven. Yet Scorpio and Virgo are only two signs apart, a sextile distance, and they do not share a modality: one is fixed, the other mutable.
These out-of-sign squares count like the others, with their orb and their place in the grid. They are read with a nuance, though: the friction is there, but the two signs are not at odds by nature. Conversely, the square from Mars (3°38' Sagittarius) to the same Midheaven joins two mutable signs, as the classical scheme expects.
Chapter I also discusses two wider squares, Mars square Chiron (4°14', Applying) and Neptune square Lilith (4°55'). In all, her grid counts eleven squares out of forty lines, two fewer than conjunctions.
These entries describe astrology for everyone. Your birth chart, though, is unique: discover what your birth sky reveals about you.
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