House (astrology) - Rationale Behind Twelve Houses

Rationale Behind Twelve Houses

Babylonians started observing natural phenomena connected with ascending and culminating of the heavenly bodies. This evolved into 12 division system of houses before the discovery of the ecliptic. Later (around V c. bce) ecliptic was discovered (Schmidt&Hand "On the invariance of tropical Zodiac" and "Early house divisions in the Hellenistic era"). At the beginning this early zodiac it has no sign divisions, and only 18 bright stars were used as markers to measure planet positions. Later in Alexandria astrologers introduced the twelve signs to fit the number and probably meanings of the houses, and named constellations after them. Nowadays, practising astrologers use a 12 house division. Most theoreticians attribute 8 fold division for misinterpretation of old texts only, but one theoretician Patrice Guinard has argued, contrary to that prevailing opinion, that there is a basis for an 8 house division. One prominent astrologer, Marc Penfield, uses 8 houses - dividing each quadrant using the same technique as in Koch & Placidus. Michel Gauquelin divided Placidus houses into 36 (instead of 12) "decans" and marked beginning of the 36th "decan" (the first before ascendant) as the starting point.