The Deeper Symbolism of Freemasonry from The Meaning of Masonry by Walter Leslie Wilmshurst.

“The initiate placed in the N.E. corner is intended to see, then, that on the one side of him is the path that leads to the perpetual light of the East, into which he is encouraged to proceed, and that on the other is that of spiritual obscurity and ignorance into which it is possible for him to remain or relapse.” [via]