“The mind once enlightened cannot again become dark.”

Introduction to The Plague (1946) by Albert Camus, as translated in a 1962 edition.

Bright Side of the Road
Song lyrics, Into the Music (1979)

Source: How They Met, and Other Stories

"Notes about Music" (29 March 1946) http://web.archive.org/19991001055247/www.geocities.com/Nashville/3448/music.html also quoted in A Race of Singers: Whitman's Working-Class Hero from Guthrie to Springsteen (2000) by Bryan K. Garman, p. 244
Context: I have hoped as many hopes and dreamed so many dreams, seen them swept aside by weather, and blown away by men, washed away in my own mistakes, that — I use to wonder if it wouldn't be better just to haul off and quit hoping. Just protect my own inner brain, my own mind and heart, by drawing it up into a hard knot, and not having any more hopes or dreams at all. Pull in my feelings, and call back all of my sentiments — and not let any earthly event move me in either direction, either cause me to hate, to fear, to love, to care, to take sides, to argue the matter at all — and, yet … there are certain good times, and pleasures that I never can forget, no matter how much I want to, because the pleasures, and the displeasures, the good times and the bad, are really all there is to me.
And these pleasures that you cannot ever forget are the yeast that always starts working in your mind again, and it gets in your thoughts again, and in your eyes again, and then, all at once, no matter what has happened to you, you are building a brand new world again, based and built on the mistakes, the wreck, the hard luck and trouble of the old one.

Silence Speaks, from the chalkboard of Baba Hari Dass, 1977
Context: Q: Can intellect aid understanding? A: It helps in the beginning but cannot give full enlightenment. The mind is the main instrument to gain enlightenment, but enlightenment is only reached when the mind stops. Q: How can we stop the mind? A: Not hitting it with a hammer. Stop the mind by the mind. (p.31)

Source: One Day

Source: Burned