Quotes about secretion
page 3

“The lapse of time uncovers hidden secrets.”
Misnad al-Imām al-Jawād, p. 245
General

“The secret of great battles consists in knowing how to deploy and concentrate at the right time.”
Napoleon : In His Own Words (1916)

Original French: Le secret de la liberté est d'éclairer les hommes, comme celui de la tyrannie est de les retenir dans l'ignorance
Source: Oeuvres, Volume 2 http://books.google.com/books?id=iSMVAAAAQAAJ p. 253.
Breaking Down the Wall of Silence (Abbruch der Schweigemauer) (1990)

"John Wayne Gacy, Jr."
Lyrics, Illinois (2005)

On the subject of torture, in a letter to Louis Alexandre Berthier (11 November 1798), published in Correspendance Napoleon edited by Henri Plon (1861), Vol. V, No. 3605, p. 128

Source: 1930s, Power: A New Social Analysis (1938), Ch. 12: Powers and forms of governments

The Notebooks of Leonardo da Vinci (1883), XXI Letters. Personal Records. Dated Notes.

2014, Review of Signals Intelligence Speech (June 2014)

“I never brag, how real I keep it, cause it's the best secret.”
Take It In The Blood
On Albums, It Was Written (1996)

Paraphrased and misattributed, actually from "Die Musik des neunzehnten Jahrhunderts und ihre Pflege: Methode der Musik" ("The Music of the Nineteenth Century, and its Culture") by Adolf Bernhard Marx: "Die Kunst ist stets und überall das geheime Bekenntnis und unsterbliche Denkmal ihrer Zeit." ("Art is always and everywhere the secret confession as well as the undying monuments of its time.").
Misattributed

The Kasîdah of Hâjî Abdû El-Yezdî (1870)

" A Few Words on Secret Writing http://www.lfchosting.com/eapoe/works/essays/fwsw0741.htm" in Graham's Magazine (July 1841).

Pushkin, 19 October 1827.
as quoted in Pushkin, Alexander (2009). Selected Lyric Poetry. Northwestern University Press, p. 121.

Homilies on the Gospel of Saint John http://www.ccel.org/ccel/schaff/npnf114.iv.xxiii.html, Homily XXI

"16 Questions on the Assassination" http://karws.gso.uri.edu/JFK/The_critics/Russell/Sixteen_questions_Russell.html in The Minority of One, ed. M.S. Arnoni (1964-09-06), pp. 6-8
1960s

Evangelicæ Historiæ: Quadripartita Monas Sive Harmonia Quatuor Evangelistarum ("Harmonization of the Gospels") (1592), dedicatory letter. Quoted in Jean Van Raemdonck, Gerard Mercator: sa vie et ses oeuvres (1869), p. 25, footnote 2 http://books.google.com/books?id=18NNAAAAcAAJ&pg=PA25

1943, quoted in "World War II Almanac, 1931-1945: A Political and Military Record" - Page 293 by Robert Goralski - History - 1981.
The Man who Tapped the Secrets of the Universe
[Asiri 1950, No. 126] Asiri 1950 — Asiri, Fazl Mahmud. Rubaiyat-i-Sarmad. Shantiniketan, 1950. Quoted from SARMAD: LIFE AND DEATH OF A SUFI https://iphras.ru/uplfile/smirnov/ishraq/3/24_prig.pdf by N. Prigarina

Quote translated from his German book: Wer bin ich – und wenn ja, wie viele? Eine philosophische Reise, Goldmann, München 2007, ISBN 3-442-31143-8

Concurring in New York Times Co. v. United States, 403 U.S. 713 (1971).

“None, none descends into himself, to find
The secret imperfections of his mind.”
Ut nemo in sese tentat descendere! nemo!
Sed praecedenti spectatur mantica tergo.
Satire IV, line 23 (translated by John Dryden).
The Satires

“The secret of being a bore is to tell everything.”
Le secret d'ennuyer est celui de tout dire.
"Sixième discours: sur la nature de l'homme," Sept Discours en Vers sur l'Homme (1738)
Citas

Boisgeloup, winter 1934
As quoted in Futurism, ed. Didier Ottinger; Centre Pompidou / 5 Continents Editions, Milan, 2008
Quotes, 1930's, "Conversations avec Picasso," 1934–35

Lamb's Chapel v. Center Moriches Union Free School District, 508 U.S. 384, 398-99 (1993) (concurring) (citations omitted).
1990s

Diogenes Laërtius (trans. C. D. Yonge) The Lives and Opinions of Eminent Philosophers (1853), "Solon", sect. 13, p. 29.

Omar Khayyám, Rubaiyat (1048–1123), translation by Richard Le Gallienne
Well, well, what matters it! believe that too. note: Not a literal translation of Omar Khayyám's work, but a paraphrase according to Richard Le Gallienne own understanding.
Source: https://static1.squarespace.com/static/525669afe4b0b689af6075bc/t/525e8a8ee4b0f0a0fb6fa309/1381927566101/Talib+--+Le+Gallienne%27s+Paraphrase+and+the+Limits+of+Translation+from+FitzGerald+Rubaiyat+volume.pdf pp. 175-176
https://www.cambridge.org/core/books/fitzgeralds-rubaiyat-of-omar-khayyam/le-galliennes-paraphrase-and-the-limits-of-translation/CC05D35479CE33C2E66ABA8CF51F779B Le Gallienne's Paraphrase and the Limits of Translation']' by Adam Talib

“When it rains, you put up an umbrella. That is the secret of success in business and management.”
Kōnosuke Matsushita. Not for Bread Alone: A Business Ethos, a Management Ethic, 1984. p. 111

"The Transmission of Electric Energy Without Wires" in Electrical World and Engineer (5 March 1904)

Source: Das Ressentiment im Aufbau der Moralen (1912), L. Coser, trans. (1961), pp. 96-97

The Crisis No. I.
1770s, The American Crisis (1776–1783)

Soren Kierkegaard, Three Discourses at the Communion on Fridays.1 John 3: From Cristian Discourses & The Lilies of the Field & The Birds of the Air, & Discourses at the Communion on Fridays 1848 Translated by Walter Lowrie 1940, 1961 Galaxy Books P. 298-299
1840s, Christian Discourses (1848)

“I have always felt that one of the secrets of real beauty is simplicity.”
Article written as guest columnist for Arlene Dahl, headlined "Rita Hayworth Sees Simplicity As Part Of Beauty" in The Toledo Blade (11 March 1964) http://news.google.com/newspapers?nid=1350&dat=19640311&id=AP1OAAAAIBAJ&sjid=WAEEAAAAIBAJ&pg=7406,218312

Letter to James F. Morton (18 January 1931), quoted in "H.P. Lovecraft, a Life" by S.T. Joshi, p. 587
Non-Fiction, Letters, to James Ferdinand Morton, Jr.

Oeconomicus (The Economist) XIX.15 (as translated by H. G. Dakyns)
Xenophon

“What is the secret of your serenity?
Said the Master "Wholehearted cooperation with the inevitable.”
Source: One Minute Nonsense (1992), p. 22

“It is a blatant, open secret that this attack on the Twin Towers was done by George Bush himself.”
Condemning 11th September attacks, 31 July, 2008. http://www.memritv.org/clip/en/1846.htm.

Vol. II, Ch. XXI, p. 520.
(Buch II) (1893)

"He" - Written 11 August 1925; first published in Weird Tales, Vol. 8, No. 3 (September 1926)
Fiction

Source: Jack: Straight from the Gut (2001), Ch. 24.

The life of Pasteur (1911), Volume II http://archive.org/stream/lifeofpasteurtra02valluoft/lifeofpasteurtra02valluoft_djvu.txt. p. 228
Variant translation: "Do not let yourself be tainted with a barren skepticism.", as quoted in The Louisville & Nashville Employes' Magazine Vol. 20 (1944), p. 28

1780s, The Newburgh Address (1783)

Column published in Guns and Ammo (1 September 1975)
1970s

Lawh-i-Maqsúd http://reference.bahai.org/en/t/b/TB/tb-12.html (Tablet of Maqsúd)

“All charming people, I fancy, are spoiled. It is the secret of their attraction.”
"The Portrait of Mr. W. H.," Blackwood's Magazine, July 1889 http://books.google.com/books?id=QfczAQAAMAAJ&q=%22All+charming+people+I+fancy+are+spoiled+It+is+the+secret+of+their+attraction%22&pg=PA4#v=onepage

“The secret of life is to find out what one really wants.”
Source: A Lodge in the Wilderness (1906), Ch. II, p. 43

Breton's quote in the Introduction to the exhibition of Gorky's first show, Julien Levy Gallery, March 1945; as quoted in Arshile Gorky, – Goats on the roof, ed. by Matthew Spender, Ridinghouse, London, 2009, pp. 257-258
after 1930

Actually Henry Wadsworth Longfellow, Driftwood (1857)
Misattributed

“The secret of happiness is to admire without desiring. And that is not happiness.”
No. 33.
Aphorisms (1930)

Reading Rockets interview http://www.readingrockets.org/books/interviews/stine/transcript

“Reprove your friend in secret and praise him openly.”
The Notebooks of Leonardo da Vinci (1883), XIX Philosophical Maxims. Morals. Polemics and Speculations.

“Tis a secret: none knows how it comes, how it goes:
But the name of the secret is Love!”
Source: Sylvie and Bruno Concluded (1893), Chapter 19: A Fairy Duet

Letter to Elizabeth Toldridge (9 October 1931), in Selected Letters III, 1929-1931 edited by August Derleth and Donald Wandrei, p. 423
Non-Fiction, Letters

Source: 1970s, Outline of a new approach to the analysis of complex systems and decision processes (1973), p. 28

Confusion of Feelings or Confusion: The Private Papers of Privy Councillor R. Von D (1927)

Spiritual Canticle of The Soul and The Bridegroom

Interview with Edward R. Murrow, A Conversation with J. Robert Oppenheimer (1955)

Source: Das Ressentiment im Aufbau der Moralen (1912), L. Coser, trans. (1961), pp. 88-92

Socrates, pp. 147–8
Eupalinos ou l'architecte (1921)

“The aphorism "as a man thinketh in his heart so is he" contains the secret of life.”
Source: Striking Thoughts (2000), p. 4; Lee here quotes Proverbs 23:7 "As he thinketh in his heart, so is he."