Luna is the Latin name of the Moon-Goddess. In Gnostic symbolism and magic texts she is coupled with Sol, the male sun. Together they represent fire and water, the combination produced the Blood of Life.
Chaucer wrote of Luna:
Luna the Serene
Chief goddess of the ocean and its queen,
Though Neptune have therein his deity,
Is over him and empress of the sea.
Many myths present the Moon-Goddess as the Creatress who first drifted alone on the primal ocean of chaos until she decided to bring orderly forms out of elemental formlessness. She has been known in pagan cultures as “Moon Shining Over the Ocean” and called Luonnatar, Daughter of Nature. But she was not the daughter of anything; she existed all alone in primordial time, until she tired of loneliness and decided to create a world.
Christians claimed the worshippers of Luna were crazy, hence the word “lunatic”, a person moon-touched or moon-struck. To this day, many people believe lunacy is affected by the moon, being characterized by increased psychic disturbances when the moon is full.
Text source: Encyclopedia of Myths and Secrets