Full context:   To my knowledge, we do not know the origin of this assimilation, nor of the association between elements and quadrants. It may be that these models originated at the crossroads that was Alexandria, and that two rival systems competed, one "Egyptian" and the other "Chaldean (in this matter as in numerous others), associating at some early stage the elements with the Zodiacal quadrants, according to astro-meteorological considerations (WATER rain, floods, AIR storms, FIRE drought, EARTH earthquakes) and according to seasonal variations in climate (humidity, heat, dryness, cold): in other words, an Egyptian system of FIRE-WATER-AIR-EARTH (marked by a rainy summer and the flooding of the Nile), which would have given birth to the "classical" system through attribution of the seasonal quality to the first sign of the season (Aries Fire, Cancer Water ...) and to a generalization by means of the trigons, and a Babylonian system AIR-FIRE-EARTH-WATER (marked by a rainy winter) that can be found in the work of Paul of Alexandria.