Latin for Light, which see. Freemasonry anciently received, among other names, that of Lux, because it is that sublime doctrine of truth by which the pathway of him who has attained it is to be illumined in the pilgrimage of life. Among the Rosicrucians, light was the knowledge of the philosopher's stone; and Mosheim says that in chemical language the cross was an emblem of light, because it contains within its figure the forms of the three figures of which LVX., or Light, is composed.

- Source: Mackey's Encyclopedia of Freemasonry

LUX E TENEBRIS

Latin, meaning Light out of darkness. A motto very commonly used in the caption of Masonic documents as expressive of the object of Freemasonry, and what the true Freemason supposes himself to have attained. It has a recondite meaning. In the primeval ages and in the early mythology, darkness preceded light. "In the thought," says Cox, "of these early ages, the sun was the child of night or darkness" (Aryan Mythology I, page 43).

So lux being Truth or Freemasonry, and tenebrae, or darkness, the symbol of initiation, luxe tenebris is Masonic truth proceeding from initiation. A Lodge at London comprising Brethren devoted especially to the welfare of blind persons has been given this appropriate name.

- Source: Mackey's Encyclopedia of Freemasonry

LUX FIAT ET LUX FIT

Latin, meaning Let there be light, and there was light. A motto sometimes prefixed to Masonic documents.