“At eleven o’clock this morning came to an end the cruellest and most terrible War that has ever scourged mankind. I hope we may say that thus, this fateful morning, came to an end all wars.”

1961, UN speech
Context: Mankind must put an end to war — or war will put an end to mankind.
So let us here resolve that Dag Hammarskjold did not live, or die, in vain. Let us call a truce to terror. Let us invoke the blessings of peace. And as we build an international capacity to keep peace, let us join in dismantling the national capacity to wage war.
Context: We meet in an hour of grief and challenge. Dag Hammarskjold is dead. But the United Nations lives. His tragedy is deep in our hearts, but the task for which he died is at the top of our agenda. A noble servant of peace is gone. But the quest for peace lies before us.
The problem is not the death of one man — the problem is the life of this organization. It will either grow to meet the challenges of our age, or it will be gone with the wind, without influence, without force, without respect. Were we to let it die, to enfeeble its vigor, to cripple its powers, we would condemn our future. For in the development of this organization rests the only true alternative to war — and war appeals no longer as a rational alternative. Unconditional war can no longer lead to unconditional victory. It can no longer serve to settle disputes. It can no longer concern the great powers alone. For a nuclear disaster, spread by wind and water and fear, could well engulf the great and the small, the rich and the poor, the committed and the uncommitted alike. Mankind must put an end to war — or war will put an end to mankind.
So let us here resolve that Dag Hammarskjold did not live, or die, in vain. Let us call a truce to terror. Let us invoke the blessings of peace. And as we build an international capacity to keep peace, let us join in dismantling the national capacity to wage war.

Source: Watchmen

1990s, The End of History and the Last Man (1992)

Letter to Kingsley Martin on the Spanish Civil War (9 August 1937), quoted in Kingsley Martin, Editor: A Second Volume of Autobiography, 1931–45 (1968), p. 257
1930s

1950s, The Russell-Einstein Manifesto (1955)
Context: Here, then, is the problem which we present to you, stark and dreadful and inescapable: Shall we put an end to the human race; or shall mankind renounce war? People will not face this alternative because it is so difficult to abolish war.
The abolition of war will demand distasteful limitations of national sovereignty. But what perhaps impedes understanding of the situation more than anything else is that the term "mankind" feels vague and abstract. People scarcely realize in imagination that the danger is to themselves and their children and their grandchildren, and not only to a dimly apprehended humanity. They can scarcely bring themselves to grasp that they, individually, and those whom they love are in imminent danger of perishing agonizingly. And so they hope that perhaps war may be allowed to continue provided modern weapons are prohibited.
This hope is illusory. Whatever agreements not to use H-bombs had been reached in time of peace, they would no longer be considered binding in time of war, and both sides would set to work to manufacture H-bombs as soon as war broke out, for, if one side manufactured the bombs and the other did not, the side that manufactured them would inevitably be victorious.

Dedication, p. 5; this refers to the quotation of Friedrich Schiller from which Asimov derived the title of this novel: "Against stupidity the gods themselves contend in vain."
The Gods Themselves (1972)

Chronicles of the Canongate, Chap. iv.
Bartlett's Familiar Quotations, 10th ed. (1919)

Act i, scene 1. Compare: "But with the morning cool reflection came", Sir Walter Scott, Chronicles of the Canongate, chap. iv. Scott also quotes this in his notes to "The Monastery", chapter iii, note 11; and with "calm" substituted for "cool" in "The Antiquary", chapter v.; and with "repentance" for "reflection" in "Rob Roy", chapter xii.
The Fair Penitent (1703)

Savitri (1918-1950), Book Three : The Book of the Divine Mother
Context: I saw the Omnipotent's flaming pioneers
Over the heavenly verge which turns towards life
Come crowding down the amber stairs of birth;
Forerunners of a divine multitude,
Out of the paths of the morning star they came
Into the little room of mortal life.
I saw them cross the twilight of an age,
The sun-eyed children of a marvellous dawn,
The great creators with wide brows of calm,
The massive barrier-breakers of the world
And wrestlers with destiny in her lists of will,
The labourers in the quarries of the gods,
The messengers of the Incommunicable,
The architects of immortality.