This is a follow-up to my previous post about triplicity rulers.
In the 1940 Robbins/Loeb translation of Tetrabiblos Ptolemy discusses triplicities on pages 83 to 87, “Of the Triangles.” Ptolemy begins by saying that the zodiac is divided into four harmonious equilateral triangles. He then considers the “sect” of the planets to decide which ones govern each “triangle” or triplicity. [Solar sect planets are the Sun, Jupiter, and Saturn. Lunar sect planets are the Moon, Venus, and Mars.]
The first triangle passes through the Fire signs Aries, Leo, and Sagittarius – three masculine signs which are the domiciles of Mars, the Sun, and Jupiter. Because Mars is not “of the solar sect” but rather of the “sect of the Moon,” this triangle is assigned to the Sun by day and Jupiter by night. Ptolemy states that Mars cannot be a Fire triplicity ruler because it belongs to the lunar sect, but he does not make explicit whether he considers Saturn to be a co-ruler because it belongs to the solar sect.
The second triangle through Taurus, Virgo, and Capricorn consists of feminine Earth signs and is therefore governed by the Moon at night and Venus during the day. Saturn is excluded because it belongs to the sect of the Sun. Ptolemy does not mention whether he considers Mars a co-ruler because it is of the lunar sect.
The third triangle connects the masculine Air signs Gemini, Libra, and Aquarius. It is assigned to Saturn by day (because Saturn is of the solar sect) and to Mercury by night. Ptolemy adds that “the sect of Jupiter has familiarity with Saturn, inasmuch as it is diurnal.” It is not clear whether Ptolemy then considers Jupiter a participating ruler.
The fourth triangle is drawn through the feminine Water signs Cancer, Scorpio, and Pisces. Mars is assigned to this triangle because it is of the lunar sect and has domicile in Scorpio. Along with Mars, “on account of the sect and the femininity of the signs, the Moon by night and Venus by day are co-rulers. Only for the Water triplicity does Ptolemy explicitly mention that Mars is a co-ruler along with the other members of the lunar sect, Venus and the Moon.
Here is a summary of Ptolemy’s triplicity rulers:
Ptolemy Day Night Participating
- Fire: Sun Jupiter ? Saturn ?
- Air: Saturn Mercury ? Jupiter ?
- Water: Venus Moon Mars
- Earth: Venus Moon ? Mars ?
It seems clear that Ptolemy was describing the 1st century system of Dorotheus. Ptolemy also links the triplicities to variations in climate to give a scientific justification for this classification system.
A perusal of Ptolemy’s arguments suggests that Lilly misunderstood Ptolemy when he gave day and night rulership of the Water triplicity to Mars. Ptolemy was quite explicit in stating that Venus rules Water by day and the Moon rules Water but night. Mars is a participating ruler of the Water triplicity regardless of the time of day.
As I understand him, Ptolemy is saying that Mars always governs the Water triplicity along with Venus and the Moon because all three are of the nocturnal or lunar sect. During the day, however, the influence of Venus on the Water signs is more strongly felt than that of the Moon, whereas at night the influence of the Moon trumps that of Venus.
Morin’s approach, while considering solar and lunar sect, lay more emphasis on dignity by triplicity being due to the ruling planets sharing the elemental nature of the signs in the triplicity. His logic seems to be that any planet that has domicile, the most powerful dignity, in a sign is a welcome guest in any other sign of the same element.
The Moon, for example, rules the Water sign Cancer. Thus, according to Morin, the Moon would be comfortable in any of the three Water signs where it would have dignity by being a domicile ruler within the Water triplicity. In Scorpio, the Moon has dignity by triplicity because Scorpio is a Water sign. The Moon is also in its fall in Scorpio, which is opposite Taurus, the Moon’s sign of exaltation. Though the Moon has dignity by triplicity in Scorpio, the Moon is uncomfortable (in fall) there because Mars is the absolute ruler of Scorpio. Mars, ruling Scorpio, would like the Moon to rape, kill, and plunder — activities which the Moon finds distasteful because the Moon would prefer to nurture, mother, and heal. Nonetheless, the Moon is quite at home with the watery, nocturnal nature of the Scorpio environment.
Below is Ashmand’s translation FROM THE GREEK PARAPHRASE OF PROCLUS
London, Davis and Dickson 
18. Of the Triangles.
The familiarity by triangles is as follows. Inasmuch as the triangular and equilateral form is most harmonious with itself, the zodiac also is bounded by three circles, the equinoctial and the two tropics, and its twelve parts are divided into four equilateral triangles. The first of these, which passes through Aries, Leo, and Sagittarius, is composed of three masculine signs and includes the houses of the sun, oc Mars, and of Jupiter. This triangle was assigned to the sun and Jupiter, since Mars is not of the solar sect. The sun assumes first governance of it by day and Jupiter by night. Also, Aries is close to the equinoctial circle, Leo to the summer solstice and Sagittarius to the winter solstice. This triangle is preeminently northern because of Jupiter’s share in its government, since Jupiter is fecund and windy, similarly to the winds from the north.
However, because of the house of Mars it suffers an admixture of the
south-west wind and is constituted Borrolibycon, because Mars causes such winds and also because of the sect of the moon and the feminine quality of the occident.
The second triangle, which is the One drawn through Taurus, Virgo, and Capricorn, is composed of three feminine signs, and consequently was assigned to the moon and Venus; the moon governs it by night and Venus by day. Taurus lies toward the summer tropic, Virgo toward the equinox, and Capricorn toward the winter tropic. This triangle is made preeminently southern because of the dominance of Venus, since this star through the heat and moisture of its power produces similar winds; but as it receives an admixture of Apeliotes because the house of Saturn, Capricornus, is included within it, it is constituted Notapeliotes in contrast to the filet triangle, since Saturn produces winds of this kind and is related to the cast through sharing in the sect of the sun.
The third triangle is the One drawn through Gemini, Libra, and Aquarius, composed of three masculine signs, and having no relation to Mars but rather to Saturn and Mercury because of their houses. It was assigned in turn to these, with Saturn governing during the day on account of his sect and Mercury by night. The sign of Gemini lies toward the summer tropic, Libra toward the equinox, and Aquarius toward the winter tropic. This triangle also is primarily of eastern constitution, because of Saturn, but by admixture north-eastern, because the sect of Jupiter has familiarity with Saturn, inasmuch as it is diurnal.
The fourth triangle, which is the one drawn through Cancer, Scorpio, and Pisces, was left to the only remaining planet, Mars, which is related to it through his house, Scorpio; and along with him, on account of the sect and the femininity of the signs, the moon by night and Venus by day are co-rulers. Cancer is near the summer circle, Scorpio lies close to the winter one, and Pisces to the equinox. This triangle is constituted preeminently western, because it is dominated by Mars and the moon; but by admixture it becomes south-western through the domination of Venus.