The Tetractys is a figure made up of ten points arranged in four rows, with one point in the first row, two in the second, three in the third, and four in the fourth.
In Ancient Greece, the Tetractys was seen as a symbol of the divine and was associated with the Pythagorean philosophy. The first row represented the Monad, the divine source of all things, while the second row symbolized the Dyad, which represented the contrast and duality of the universe. The third row represented the Triad, which represented harmony and balance, and the fourth row represented the Tetrad, which symbolized the four elements (earth, air, fire, and water) and the four seasons.
The Tetractys was also used as a symbol of the mystical and spiritual in various mystery schools and secret societies. In these groups, the Tetractys was seen as a symbol of creation and the power of the divine in the universe. It was also seen as a symbol of the human soul’s journey towards enlightenment.
In the Pythagorean tradition, the Tetractys was also used as a symbol of the musical harmony of the universe. In this case each row was associated with a musical interval.
In some spiritual traditions, the Tetractys has also been associated with the elements of nature (fire, air, water, earth) and the four directions (east, north, west, south).