To understand the power of two, we can look to ancient cultures and their depiction of doubles, bi-lines, two headed images, and summer/winter duality. These motifs or images were used to express intensification, potency, and abundance.
Doubles appear on painted vases as far back as 4500-3500 B.C. in the form of two images such as animals or egg shaped ovals. Double pairs of snakes can be found on ivory seals from the Middle Minoan period, early 2nd millennium. The many double-egg-shaped buttocks of sculptures, reliefs, and engravings from some 20,000 years ago, may represent intensified potency and fertility. Some female forms are also created with pairs of snakes across the abdomen and buttocks and may symbolize supernatural potency expressed by the doubling device, "the power of two" according to Marija Gimbutas in The Language of The Goddess.
The double fruit or double grain motif may represent plant fertility in relation to the Divine Feminine. A glyph of two ellipses joined at one end was used on seals and megaliths throughout Old Europe. This image is often paired with the tree and sprouting bud in Middle Minoan ceramic art.
Two lines or bi-lines have been used on figurines to symbolize the power of two as intensified fertility and potency as it often appears across the breasts, abdomen, and buttocks. Bi-lines also appear on the face and arms of figures of the Goddess. An ancient clay stamp with incised lines, from 5800-5500 B.C., represents the alchemical process of two coming together to form many.
(continued in The Power of Two Part 2)