“On their own merits modest men are dumb.”

“An Unprejudiced Mind,” pp. 311-312
Pretexts: Reflections on Literature and Morality (1964)

Epistle to William Hogarth (July 1763)

"Distichs" in The Poems of Goethe (1853) as translated in the original metres by Edgar Alfred Bowring
Context: Who is the happiest of men? He who values the merits of others,
And in their pleasure takes joy, even as though 'twere his own.
Not in the morning alone, not only at mid-day he charmeth;
Even at setting, the sun is still the same glorious planet.

Source: Married Lovers

Vol. I, Ch. III, The World As Representation: Second Aspect
The World as Will and Representation (1819; 1844; 1859)

Kissinger has denied saying it.
The only evidence that Kissinger ever said this was a claim in the book, The Final Days, by Bob Woodward and Carl Bernstein, in chapter 14 (p.194 in the 1995 paperback edition). Woodward & Bernstein claimed that one of Kissinger's political foes, Alexander Haig, had told someone unnamed, that he (Haig) had heard Kissinger say it. That's triple hearsay, made even weaker by the fact that one of the parties is anonymous. Kissinger has denied ever saying it, and it was never substantiated by Haig, nor by anyone of known identity who claimed to have heard it. As Kirkus Reviews noted about the whole book, "none of it is substantiated in any assessable way."
In fact, the quote is not even very plausible, on its face. Kissinger served with distinction in the U.S. Army during WWII, and was awarded the Bronze Star. He has always been very respectful of other servicemen and their sacrifices. For him to have said such a thing would have been wildly out of character. In fact, the awkward phrasing doesn't even sound like Kissinger, whose English prose is consistently measured and careful, despite his heavy accent, even when he speaks extemporaneously.
Misattributed

Quoted from Lal, K. S. (1990). Indian muslims: Who are they. Chapter 2.
Fatawa-i-Jahandari

Page 96
Ender's Game series, First Meetings in the Enderverse (2003), Teacher's Pest
Source: First Meetings in Ender's Universe

Cut down the proud towering thoughts that you get into you, or see they be pure as well as high. There is a nobler ambition than the gaining of all California would be, or the getting of all the suffrages that are on the planet just now.
1860s, On The Choice Of Books (1866)