“In adopting a republican form of government, I not only took it as a man does his wife, for better or for worse, but what a few men do with their wives, I took it knowing all of it bad qualities. Neither ingratitude, therefore, nor slander can disappoint expectation nor excite surprise. If, in arduous circumstances, the voice of my country should call for my services, and i have the well founded belief, that they can be useful, they shall certainly be rendered; but I hope that no such circumstances will arise and in the mean time, 'pleas'd let me trifle away.”

Source: Down and out in Paris and London (1933), Ch. 38
Context: My story ends here. It is a fairly trivial story, and I can only hope that it has been interesting in the same way as a trivial diary is interesting. … At present I do not feel I have seen more than the fringe of poverty.
Still, I can point to one or two things I have definitely learned by being hard up. I shall never again think that all tramps are drunken scoundrels, nor expect a beggar to be grateful when I give him a penny, nor be surprised if men out of work lack energy, nor subscribe to the Salvation Army, nor pawn my clothes, nor refuse a handbill, nor enjoy a meal at a smart restaurant. That is a beginning.

Source: The Cruise of the 'Nona (1925), pp. 48-9
Belloc writes that Cardinal Manning said this sentence to him "when I was but twenty years old" (p. 47), i.e. in 1890 or 1891.
Context: The profound thing which Cardinal Manning said to me was this: all human conflict is ultimately theological. […]This saying of his (which I carried away with me somewhat bewildered) that all human conflict was ultimately theological: that is, that all wars and revolutions, and all decisive struggles between parties of men arise from a difference in moral and transcendental doctrine, was utterly novel to me. To a young man the saying was without meaning: I would almost have said nonsensical, save that I could not attach the idea of folly to Manning. But as I grew older it became a searchlight: with the observation of the world, and with continuous reading of history, it came to possess for me a universal meaning so profound that it reached to the very roots of political action; so extended that it covered the whole.It is, indeed, a truth which explains and co-ordinates all one reads of human action in the past, and all one sees of it in the present. […] All tragedy is the conflict of a true right and a false right, or of a greater right and a lesser right, or, at the worst, of two false rights. Still more do men pretend in this time of ours, wherein the habitual use of the human intelligence has sunk to its lowest, that doctrine is but a private individual affair, creating a mere opinion. Upon the contrary, it is doctrine that drives the State; and every State is stronger in the degree in which the doctrine of its citizens is united. Nor have I met any man in my life, arguing for what should be among men, but took for granted as he argued that the doctrine he consciously or unconsciously accepted was or should be a similar foundation for all mankind. Hence battle.

III, lines 75-78, John Dryden, trans.
Satires, Satire III

"The True History", sect. 4; vol. 2, p. 137.

Encouraging his men to re-enlist in the army (31 December 1776)
1770s

Cited in " Cathy Newman: 'The internet is being written by men with an agenda' https://www.theguardian.com/media/2018/mar/19/cathy-newman-the-internet-is-being-written-by-men-with-an-agenda", 25 March 2018.

Success.
Just Folks (1917)

Source: Don Quixote de la Mancha (1605–1615), Part II (1615), Book III, Ch. 33, as translated by Pierre Antoine Motteux in The History of the Ingenious Gentleman Don Quixote of La Mancha (1701)
Variant translations:
I'm kind-hearted by nature, and full of compassion for the poor; there's no stealing the loaf from him who kneads and bakes; and by my faith it won't do to throw false dice with me; I am an old dog, and I know all about 'tus, tus;' I can be wide-awake if need be, and I don't let clouds come before my eyes, for I know where the shoe pinches me; I say so, because with me the good will have support and protection, and the bad neither footing nor access. And it seems to me that, in governments, to make a beginning is everything; and maybe, after having been governor a fortnight, I'll take kindly to the work and know more about it than the field labour I have been brought up to.
Honesty's the best policy.
Context: I was ever charitable and good to the poor, and scorn to take the bread out of another man's mouth. On the other side, by our Lady, they shall play me no foul play. I am an old cur at a crust, and can sleep dog-sleep when I list. I can look sharp as well as another, and let me alone to keep the cobwebs out of my eyes. I know where the shoe wrings me. I will know who and who is together. Honesty is the best policy, I will stick to that. The good shall have my hand and heart, but the bad neither foot nor fellowship. And in my mind, the main point of governing, is to make a good beginning.

Source: Understanding International Conflicts: An Introduction to Theory and History (6th ed., 2006), Chapter 1, Is There an Enduring Logic of Conflict in World Politics?, p. 2.