“Enlightenment is the inner light of wisdom that is permanently free from all mistaken appearance, and whose function is to bestow mental peace upon each and every living being every day.”

Source: View from the UN (1978), p. 23
Context: It is far from my intention to claim that I have reached a very high stage on the path to attainment of the highest wisdom, or that I have attained complete "inner peace." However, I can claim that I practice bhavana every day. I try to cultivate the ethical aspects of Buddhism, and I believe that I have attained a greater degree of emotional equilibrium than most people. This explains why the tragic news of the sudden death (in a traffic accident) of my only son, Tin Maung Thant, on May 21, 1962, with minimal emotional reaction. For are not birth and death the two phases of the same life process? According to the Buddha, birth is followed by death, but death, in turn, is followed by rebirth.

Source: What I Talk About When I Talk About Running

Incidentals (1904); this is sometimes paraphrased: "I am an idealist. I believe in everything — I am only looking for proofs."
Context: Back of every mistaken venture and defeat is the laughter of wisdom, if you listen. Every blunder behind us is giving a cheer for us, and only for those who were willing to fail are the dangers and splendors of life. To be a good loser is to learn how to win. I was sure there are ten men in me and I do not know or understand one of them. I could safely declare, I am an idealist. A Parisian cynic says "I believe in nothing. I am looking for clues." My statement would be : I believe in everything — I am only looking for proofs.

Quoted in The Adornment of the Spiritual Marriage (1916) by C. A. Wynschenk Dom, p. 6
Context: God being a common good, and His boundless love being common to all, He gives His grace... to all men, Pagan and Jew, good or evil... Thus God is a common light and a common splendour, enlightening heaven and earth, and every man, each according to his need and worth.

Source: A Heartbreaking Work of Staggering Genius

From 1980s onwards, Critical Path (1981)
Context: I am convinced that human continuance depends entirely upon: the intuitive wisdom of each and every individual... the individual's integrity of speaking and acting only on the individual's own within-self-intuited and reasoned initiative... the individual's never joining action with others as motivated only by crowd-engendered-emotionalism, or a sense of the crowd's power to overwhelm, or in fear of holding to the course indicated by one's own intellectual convictions.

Journal entry (18 November 1861), Ch. 5 : The Beginning of the War.
Lucy Larcom : Life, Letters, and Diary (1895)
Context: Much of our Christianity is not of a sufficiently enlarged type to satisfy an educated Hindoo; not that Unitarianism is necessary, for that system has but a surface-liberalism which can become very hard, and finally very narrow, as its history among us has often proved. It is not a system at all that we want: it is Christ, the "wisdom of God and the power of God," Christ, the loving, creating, and redeeming friend of the world, Christ, whose large, free being enfolds all that is beautiful in nature and in social life; and all that is strong and deep and noble in the sanctuary of every living soul. When Christians have truly learned Christ, they can be true teachers.

"The Power of a State Developed by Mental Culture", an address to the Mercantile Library Association (18 November 1844), published in The Works of Rufus Choate : Memoir, Lectures and Addresses (1862), edited by Samuel Gilman Brown.