Thema Mundi

The Thema Mundi.

The Thema Mundi (World Theme, with 'theme' being a word that also means chart) was a mythical horoscope used in Hellenistic astrology that shows the supposed positions of the seven visible planets (including the Sun and Moon) at the beginning of the universe. It exemplifies the logic behind the sign rulerships, exaltations, and meanings of the aspects, among other things. In this sense, it is an astrological key.

The chart is significant because it up-ends the theory that the houses and the signs are directly correlated. Modern astrology assumes that Aries, the first sign, conveys its nature to the 1st house. However, because the Thema Mundi has the sign Cancer in the ascendant, rather than Aries, the suggestion is that human nature, rather than being aggressive and of the nature of Aries and Mars, is nurturing and more of the nature of Cancer and the Moon.

Properly understood, this chart will lead to a rethinking of the meaning of all 12 houses, adding a layer of historically-grounded depth to interpretations.

Structure

The Thema Mundi shows:

• Cancer rising, with the Moon in Cancer
• The Sun in Leo
• Mercury in Virgo
• Venus in Libra
• Mars in Scorpio
• Jupiter in Sagittarius
• Saturn in Capricorn

Rationale

The Thema Mundi's structure provided a backing for many of the concepts in Hellenistic astrology.

Planetary domiciles

The Sun and Moon, the two luminaries, are assigned to the two signs that correspond to the brightest and warmest times of the year in the Northern Hemisphere, Cancer and Leo. The other planets are assigned to signs by halving the zodiac between Cancer and Leo and assigning each planet to one sign on the solar half and each on the lunar half. Mercury is assigned to the two signs next to the luminaries, Gemini and Virgo, because it never travels more than one sign away from the Sun. Venus is assigned to the next two signs, Taurus and Libra, because it never gets more than two signs away. Jupiter and Mars are assigned to their signs Sagittarius and Pisces, and Aries and Scorpio, respectively, in this same way. Finally Saturn is assigned to Capricorn and Aquarius because of the cold and lack of light during this time of the year.

Astrological aspects

The natures of astrological aspects are determined by the planets' configurations to the luminaries in the Thema Mundi. In it, the aspects made by the planets correlate with their benefic or malefic classification.

• Saturn makes an opposition (180°) to the Moon, and so the opposition is said to be of the nature of Saturn. Saturn is the greater of the two malefics, and so the opposition is the most negative and harmful of the two negative aspects.
• Mars makes a square (90°) to the Sun, so the square is said to be of the nature of Mars. Mars is the lesser malefic, so the square is the least negative of the two aspects.
• Jupiter is making a trine (120°) to the Sun, so the trine's nature is that of Jupiter. Since Jupiter is the greater of the two benefics, the trine is said to be the most desirable positive aspect.
• Venus is making a sextile (60°) to the Sun and thus the sextile is of the nature of Venus, the weaker of the two benefics.
• Mercury is making a semi-sextile (30°, or half a sextile) to both the Sun and Venus, along with a sextile (60°) to both the Moon and Mars.

See also

• Domicile (astrology)
• Planets in astrology