Why Twelve?

 By Koenraad Elst

The present paper deals with a question of symbolism: what is so special about the number 12? Historically, the preference for the number 12 goes back to the Zodiac. Thus, the twelvestar flag of the European Union was designed, in a public contest, by a devotee of the Virgin Mary, who thought of the Apocalypse passage where a celestial virgin appears in a circle of twelve stars; and these "twelve stars", in Hebrew mazzalot (whence mazzel!, "good luck", originally "lucky star", "beneficial stellar configuration"), were a standard expression referring to the Zodiac, the division of the Ecliptic in twelve equal parts, each one of them represented by a symbol: Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, Pisces.

Though we acknowledge the intimate connection between astrology and the symbolic structure of the Zodiac, it is outside the scope of this paper to comment on the merits claimed for astrology. Indeed, we assume that stellar lore including the Zodiac precedes its use as a tool for divination, and that it is worth analyzing purely as a symbolic construct, regardless of its use by diviners. Contrary to what some astrologers claim, astronomy is very much older than astrology. But unlike astrology, the natural tendency to read "faces in the clouds", or in this case images in the stellar groupings, is probably as old as stargazing itself.

Not-so-special properties of twelve

The relationship of the number 12 with other numbers is interesting, but not really unique. Thus, it is said that 12 = 3 x 4, with the added explanation that "3 represents time" while "4 represents space". All very good, but then 10 = 2 x 5, which is not bad either and just as pregnant with number symbolism. And note that in both cases, the factors when added (rather than multiplied) yield 7, that mystical number. So, for a unique property, we must look elsewhere.

In number theory, we do meet 12 in intriguing places. It is the sum of the first three natural numbers satisfying Pythagoras's (actually Baudhayana's) theorem, 3� + 4� = 5�, and also figures in the next Pythagorean threesome: 5� + 12� = 13�. In Fibonacci's series, the 12th number happens to be 12�, or 144; it is the only number to have this property except for 1 (for the first power, the property is shared by the numbers 1 and 5, which stands at the 5th place; for the third power, there is none). There are twelve multiplications of natural numbers equalling 360 (1x360, 2x180, 3x120, 4x90, 5x72, 6x60, 8x45, 9x40, 10x36, 12x30, 15x24, 18x20). All very interesting, but less telling and unique than the properties of 12 conceived as a geometrical entity, viz. as the division of the circle into 12 equal parts.

How to divide the Ecliptic?

The Ecliptic can be divided into any number of zones. Wellknown is the division of 27 or 28 moonstations of about 13� each, marking the angular distance covered daily by the moon. The division in lunar mansions links an astronomical phenomenon, the moon's movement, with a division of space. The same principle probably underlies the division in twelve: it seems to be based on the approximately twelve lunation cycles in the solar year (whose quarterperiods of roughly seven days may also be related to the division in weeks).

But why should immutable space be subjected to divisions suggested by the coincidental and highly impermanent data of the moon's motion? There could well have been no moon at all (as is the case for Venusians), or mankind could have come into existence and designed a Zodiac millions of years ago, when the moon was closer to the earth and its cycle as expressed in earthly days or fractions of earthly years much shorter.

Freeing ourselves from the suggestions emanating from accidental circumstances, we want to construct a division of the circle based on nothing but the abstract circle itself, considered as a geometrical figure, hence part of a continuum of geometrical constructions. Which division of the circle is intrinsically most meaningful to the whole project of symbolically representing the diverse aspects of the universe with the sections of the ecliptical circle?