"In the higher degrees of Scottish Freemasonry, there are two mottos whose meaning is related to some of the considerations we have outlined above: one is Post Tenebras Lux and the other Ordo ab Chao; and in truth their meanings are so closely connected as to be almost identical, although Ordo ab Chao is perhaps susceptible to a broader application. In fact, they both refer to initiatory "enlightenment", the first directly and the second consequentially, since it is the original vibration of Fiat Lux that determines the beginning of the cosmogonic process as a result of which "chaos" will be ordered to become the "cosmos". In traditional symbolism, darkness always represents the state of undeveloped potentialities that constitute chaos; and correlatively, light is related to the manifested world, in which these potentialities will be actualised, that is, to the “cosmos”, an actualisation that is determined or measured, at each moment of the process of manifestation, by the extension of the “sun's rays” that depart from the central point where the initial Fiat Lux was uttered. Light is therefore effectively “after darkness”, not only from a "macrocosmic" point of view, but also from a "microcosmic" point of view which is that of initiation, since, from this point of view, darkness represents the profane world from which the recipient comes, or the profane state in which he initially finds himself, until the precise moment when he becomes initiated by “receiving the light”. Through initiation, the being therefore passes “from darkness to light”, just as the world, at its origin (and the symbolism of “birth” is equally applicable in both cases), passed “from darkness to light” by virtue of the act of the creative and ordering Word; and consequently initiation is truly, according to a very general characteristic of traditional rites, an image of “what was done in the beginning”."
January 1, 1970
https://en.wikiquote.org/wiki/Ren%C3%A9_Gu%C3%A9non