“It must be recognized that the real truths of history are hard to discover. Happily, for the most part, they are rather matters of curiosity than of real importance.”

Wang Kwo-tsai (2017) cited in " Work hours of tour bus drivers to be cut: MOTC http://focustaiwan.tw/news/asoc/201702200010.aspx" on Focus Taiwan, 20 February 2017

Source: World War Z: An Oral History of the Zombie War

Act V, scene iv
The Double Dealer (1694)

Variant: And almost idly, in a kind of sidethought, Eddie discovered one of his childhood's great truths. Grownups are the real monsters, he thought.
Source: It (1986)

21 Lessons for the 21st Century

Source: The Necessary Angel: Essays on Reality and the Imagination

Report on Manufactures (1791)
Context: It ought readily to be conceded, that the cultivation of the earth as the primary and most certain source of national supply, as the immediate and chief source of subsistence to man, (...) has intrinsically a strong claim to pre-eminence over every other kind of industry. But, that it has a title to any thing like an exclusive predilection, in any country, ought to be admitted with great caution. That it is even more productive than every other branch of Industry requires more evidence, than has yet been given in support of the position. That its real interests, precious and important as without the help of exaggeration, they truly are, will be advanced, rather than injured by the due encouragement of manufactures, may, it is believed, be satisfactorily demonstrated. And it is also believed that the expediency of such encouragement in a general view may be shewn to be recommended by the most cogent and persuasive motives of national policy.

Anti-Goeze (1778), as quoted in God Is Not Great (2007), by Christopher Hitchens , Ch. 19
Context: The true value of a man is not determined by his possession, supposed or real, of Truth, but rather by his sincere exertion to get to the Truth. It is not possession of the Truth, but rather the pursuit of Truth by which he extends his powers and in which his ever-growing perfectibility is to be found. Possession makes one passive, indolent, and proud. If God were to hold all Truth concealed in his right hand, and in his left only the steady and diligent drive for Truth, albeit with the proviso that I would always and forever err in the process, and offer me the choice, I would with all humility take the left hand, and say: Father, I will take this one—the pure Truth is for You alone.

Also attributed to Robert H. Schuller