“I lacked the courage to investigate the weaknesses of the wicked, because I discovered they are the same as the weaknesses of the saintly.”

Source: 1790s, The Marriage of Heaven and Hell (1790–1793), Proverbs of Hell, Line 49

(15 July 2013) https://twitter.com/paulocoelho <br class="br">Twitter

Variant: She is very clever, too clever for a woman. She lacks the indefinable charm of weakness.
Source: The Picture of Dorian Gray

Source: The Unbearable Lightness of Being

Home Fires (2011), Reflection 1
Fiction

Source: Infinite Jest

I Corinthians 9:22 (KJV)
First Epistle to the Corinthians
Context: Though I be free from all men, yet have I made myself servant unto all, that I might gain the more. And unto the Jews I became as a Jew, that I might gain the Jews; to them that are under the law, as under the law, that I might gain them that are under the law; To them that are without law, as without law, (being not without law to God, but under the law to Christ,) that I might gain them that are without law. To the weak became I as weak, that I might gain the weak: I am made all things to all men, that I might by all means save some.

Source: QED: The Strange Theory of Light and Matter (1985), p. 15

Source: Blood And Gold