“The mystery brings peace to my eyes, not blindness.”

After the invasion of Iraq -and after sending his tanks and artillery home- Mattis sent this message to the Iraqi leaders in every area his men served in, as quoted in Fiasco: The American Military Adventure in Iraq (2006) by Thomas E. Ricks; as excerpted in Armed Forces Journal (August 2006) http://www.armedforcesjournal.com/fiasco/

1914: "If…we were to go back to…'an eye for an eye and a tooth for a tooth,' there would be very few [Honourable] Gentlemen in this House who would not…be blind and toothless." — George Perry Graham, during a debate on capital punishment before the Canadian House of Commons. Official Report of the Debates of the House of Commons of the Dominion of Canada, Third Session-Twelfth Parliament, Vol CXIII, p. 496, February 5, 1914. http://parl.canadiana.ca/view/oop.debates_HOC1203_01/508
1950: "An-eye-for-an-eye-for-an-eye-for-an-eye … ends in making everybody blind" in The Life of Mahatma Gandhi by Louis Fischer (1950), though Fischer did not attribute it to Gandhi and seemed to be giving his own description of Gandhi's philosophy.
1958: "The old law of an eye for an eye leaves everybody blind" in Stride Toward Freedom: The Montgomery Story by Martin Luther King, Jr., 1958.
1982: "An eye for an eye only ends up making the whole world blind" in the 1982 film, Gandhi. In a 1993 biographical article about screenwriter John Briley, Jon Krampner wrote, "…Gandhi never said it. Michigan graduate John Briley put those pithy words in his mouth." From "John Briley '51 - Epic Screenwriter", Michigan Today, March 1993, p. 12. http://michigantoday.umich.edu/93/Mar_and_Oct_93/Mar_93/briley.html
2006: There is a quaternary source in Yale Book of Quotations http://books.google.co.uk/books?id=w5-GR-qtgXsC&pg=PA269&dq=whole-world-blind+ (2006), in which editor Fred R. Shapiro states that the Gandhi Institute for Nonviolence stated that Gandhi's family believes it authentic, but did not provide any further reference and provided no year, place or body of work.
2006: Discussed in The Quote Verifier: Who Said What, Where, and When, by Ralph Keyes (2006), 1st ed., p. 74.
2010: Research detailed by Garson O'Toole in "An Eye for an Eye Will Make the Whole World Blind" http://quoteinvestigator.com/2010/12/27/eye-for-eye-blind/ in Quote Investigator http://quoteinvestigator.com/.
Misattributed

Cat's Eye (1988)

"An eye for an eye leaves everybody blind" is of indefinite origin, but has been disputably attributed to various figures, including Mahatma Gandhi. This variant describing it as an "old law" is attributed to King in The Words of Martin Luther King, Jr., (2008) http://books.google.com/books?id=irMxJS36904C&redir_esc=y by Coretta Scott King, Second Edition ; it also occurs in the credits of Spike Lee's movie Do the Right Thing (1989).
Disputed

"Of Love" as translated in The Infinite in Giordano Bruno : With a Translation of His Dialogue, Concerning the Cause, Principle, and One (1978) by Sidney Thomas Greenburg, p. 89
Variant translation:
Cause, Principle and One, the Sempiterne,
On whom all being, motion, life, depend.
From whom, in length, breadth, depth, their paths extend
As far as heaven, earth, hell their faces turn :
With sense, with mind, with reason, I discern
That not, rule, reckoning, may not comprehend
That power and bulk and multitude which tend
Beyond all lower, middle, and superne. <p> Blind error, ruthless time, ungentle doom,
Deaf envy, villain madness, zeal unwise,
Hard heart, unholy craft, bold deeds begun,
Shall never fill for one the air with gloom,
Or ever thrust a veil before these eyes,
Or ever hide from me my glorious sun.
As quoted in "Giordano Bruno" by Thomas Davidson, The Index Vol. VI. No. 36 (4 March 1886), p. 429
Cause, Principle, and Unity (1584)
Context: Cause, Principle, and One eternal
From whom being, life, and movement are suspended,
And which extends itself in length, breadth, and depth,
To whatever is in Heaven, on Earth, and Hell;
With sense, with reason, with mind, I discern,
That there is no act, measure, nor calculation, which can comprehend
That force, that vastness and that number,
Which exceeds whatever is inferior, middle, and highest;
Blind error, avaricious time, adverse fortune,
Deaf envy, vile madness, jealous iniquity,
Crude heart, perverse spirit, insane audacity,
Will not be sufficient to obscure the air for me,
Will not place the veil before my eyes,
Will never bring it about that I shall not
Contemplate my beautiful Sun.

From the ninth book, "The Book of Secrets"
The Pillow Book

short quotes, 31 October 1966; p. 58
1960's, Conversations with Samuel Beckett and Bram van Velde' (1965 - 1969)