Based on this theory, the first pillar, the Greek alpha, represents the mason's compass and "God as the Architect of the Universe." The second, the Greek gamma, represents the mason's square. In addition, the square represents the "vault of heaven." The third, the Greek eta, represents Jacob's ladder itself and is connected to the complete idea of seven pillars. The fourth, the Greek theta, is either "the all-seeing eye or the point within a circle." The fifth letter, the Greek iota, represents a pillar and the temple. The sixth letter, the Greek sigma, is an incomplete hexagram, otherwise known as "the blazing star or hexalpha" to the Freemasons. The last, the Greek omega, represents a lyre and David as a poet.