What is Square in Western astrology?

Definition

Square is a Western astrological aspect in which two planets sit 90 degrees apart on the zodiac, a right angle as seen from the chart's centre.

In plain words

A square is a Western astrological aspect in which two planets sit 90 degrees apart on the zodiac, a right angle as seen from the chart's centre. Classical writers such as Ptolemy grouped it with the opposition as disharmonious, because its signs are of opposite kinds. Later astrologers often describe it as a hard aspect that asks for adjustment and skill.

Also asked as

• What angle is a square?
• What orb is usually used for a square?
• Is a square harmonious or challenging?
• How is a square shown on a chart?

History

Ptolemy's Tetrabiblos, published in the Loeb Classical Library in 1940 and reproduced on Bill Thayer's site, explains that the zodiac's signs are divided into those in aspect, where the quartile encloses one right angle, three signs, and 90 degrees.¹

The square, known as the quartile or quadrate, was not an altogether undesirable aspect in classical astrology. Its signs have a strong sight of each other, so recognition and a flow of power pass between them, though the trine remained more favourable.⁵

Ptolemy's account in the Tetrabiblos sets the quartile beside the opposition as a disharmonious configuration, and later writers such as Max Heindel, in Simplified Scientific Astrology, class the Square with the Opposition as evil while designating the Sextile and Trine good.¹⁸

Quick timeline

1. Early record — Ptolemy's Tetrabiblos, published in the Loeb Classical Library in 1940 and reproduced on Bill Thayer's site, explains that the zodiac's signs are divided into those in aspect, where the quartile encloses one right angle, three signs, and 90 degrees.¹
2. Classical framework — The square, known as the quartile or quadrate, was not an altogether undesirable aspect in classical astrology. Its signs have a strong sight of each other, so recognition and a flow of power pass between them, though the trine remained more favourable.⁵
3. Later transmission — Ptolemy's account in the Tetrabiblos sets the quartile beside the opposition as a disharmonious configuration, and later writers such as Max Heindel, in Simplified Scientific Astrology, class the Square with the Opposition as evil while designating the Sextile and Trine good.¹⁸
4. Modern usage — Ptolemy writes that the quartile is disharmonious, because it is composed of signs of opposite kinds, while the trine and sextile are called harmonious because they are composed of signs of the same kind.¹

What classical and modern sources say

Classical view

Ptolemy writes that the quartile is disharmonious, because it is composed of signs of opposite kinds, while the trine and sextile are called harmonious because they are composed of signs of the same kind.¹

Classical authors treated the square as unquestionably damaging only when a malefic or unfortunate planet was involved. Dorotheus of Sidon noted that a square will not harm if both planets are well placed, dignified and receive each other amicably.⁵

Dorotheus described the quartile as an aspect of a medium amount of love, while the trine signified much love.⁵

Modern view

Even in modern times, aspects are commonly considered either easy, such as the 60° sextile or 120° trine, or hard, such as the 90° square or 180° opposition.³

Hard aspects are described as enhancing a challenge where an adjustment must be made to reach balance, which is how the Square is understood in this framework.⁴

Cafe Astrology describes the square as an aspect that creates tension between the planets involved, with tension seen as necessary to stimulate action but too much tension becoming stress.⁶

Angle, orb and interpretation

Exact angle

Square is the 90-degree relationship between two zodiacal longitudes, as Ptolemy's Tetrabiblos describes the quartile as enclosing one right angle, three signs, and 90 degrees.¹

Orb

A common allowance is 6 to 8 degrees in modern practice, though Ptolemy's traditional aspects carry an orb that varies among astrologers and traditions, so orb conventions are not astronomical constants.¹⁴

Interpretive frame

Usually described as challenging, a square can be framed as pressure that invites adjustment, skill and growth, as Cafe Astrology presents its tension as necessary to stimulate action.¹⁶

Geometry

Two rays separated by 90 degrees show the geometric definition, and the square is a quartile, a quarter of the full opposition's two right angles, as Ptolemy explains.¹

The astronomy

Square is the 90-degree relationship between two zodiacal longitudes. Ptolemy's Tetrabiblos defines the quartile as one right angle, three signs, and 90 degrees, a quarter of the full circle.¹

Square is framed as pressure that invites adjustment, skill and growth. Wikipedia's aspect overview describes hard aspects as enhancing a challenge where an adjustment must be made to reach balance.⁴

Two rays separated by 90 degrees show the geometric definition. Interpretation is kept separate from the measured angle, which is the only fixed part of the aspect.¹

Where astrologers differ

In Ptolemy's account of the planets' houses, Mars is assigned signs in quartile aspect to the luminaries, which the text links to Mars' destructive and inharmonious quality. A square is a 90° aspect, and Wikipedia's major aspects list places it among the Ptolemaic aspects first defined and used by Ptolemy in the 1st Century AD. The Square is also called a quartile, and Ptolemy's traditional major aspects include it at 90 degrees, with an orb that varies among astrologers and traditions.

Then and now

Then

Ptolemy writes that the quartile is disharmonious, because it is composed of signs of opposite kinds, while the trine and sextile are called harmonious because they are composed of signs of the same kind.¹

Now

Even in modern times, aspects are commonly considered either easy, such as the 60° sextile or 120° trine, or hard, such as the 90° square or 180° opposition.³

Worked out from the evidence

Reasoned from the cited facts, not stated outright by any one source.

Because Ptolemy calls the quartile disharmonious and Heindel places the Square with the Opposition as evil, the square carries a classical reputation for difficulty that the Tetrabiblos and Heindel's text both record, though neither source fixes the square's effect in any single case.

Because Dorotheus ranks the quartile as a medium amount of love and the square is damaging only with a malefic involved, the classical reading treats the square as neither wholly harmful nor wholly supportive, a middle position that the two sources together support.

Not yet confirmed

• Whether a square's effect depends on the orb allowed, since the sources say orb conventions vary among astrologers and traditions without settling which orb applies.
• How the square's classical damaging reading and its modern growth framing relate to each other in one chart is not settled by the cited sources.

Follow the parts of Square

Continue through Sextile, Trine.

Questions people also ask

What angle is a square?

A square is a 90-degree aspect, a relationship between two zodiacal longitudes. Ptolemy's Tetrabiblos describes the quartile as enclosing one right angle, three signs, and 90 degrees.³¹

What orb is usually used for a square?

A common allowance is 6 to 8 degrees, but orb conventions vary among astrologers and traditions. Wikipedia's aspect overview notes that Ptolemy's traditional aspects carry orbs that differ by tradition.¹⁴

Is a square harmonious or challenging?

Ptolemy's Tetrabiblos calls the quartile disharmonious because its signs are of opposite kinds. Cafe Astrology describes its tension as necessary to stimulate action, so it is often framed as challenging.¹⁶

Method and review

Every statement about Square was checked against the wording of its 8 sources (Ptolemy (LacusCurtius), Encyclopaedia Britannica, Wikipedia, Skyscript, Cafe Astrology and Wikisource), and its positions and boundaries were calculated with Astronomy Engine. How the Machine works.