The pentad--5--is the union of an odd and an even number (3 and 2). Among the Greeks, the pentagram was a sacred symbol of light, health, and vitality. It also symbolized the fifth element--ether--because it is free from the disturbances of the four lower elements. It is called equilibrium, because it divides the perfect number 10 into two equal parts.

The dodecad symbolizes war, the triad of amity, the triad of enmity, three which are life-giving, three which are death-dealing, and God, the faithful...