“I have brought myself, by long meditation, to the conviction that a human being with a settled purpose must accomplish it, and that nothing can resist a will that will stake even existence for its fulfilment.”

Quote in "Picasso", Hans L. C. Jaffe, Thames and Hudson Ltd
Attributed from posthumous publications

Written in regard to the Allied destruction of Hamburg and other German cities, p. 437
Memoirs 1925 - 1950 (1967), Germany
Context: Here, for the first time, I felt an unshakable conviction that no momentary military advantage — even if such could have been calculated to exist — could have justified this stupendous, careless destruction of civilian life and of material values, built up laboriously by human hands over the course of centuries for purposes having nothing to do with war. Least of all could it have been justified by the screaming non sequitur: "They did it to us." And it suddenly appeared to me that in these ruins there was an unanswerable symbolism which we in the West could not afford to ignore. If the Western world was really going to make a pretense of a higher moral departure point — of greater sympathy and understanding for the human being as God made him, as expressed not only in himself but in the things he had wrought and cared about — then it had to learn to fight its wars morally as well as militarily, or not fight them at all; for moral principles were a part of its strength. Shorn of this strength, it was no longer itself; its victories were not real victories; and the best it would accomplish in the long run would be to pull down the temple over its own head. The military would stamp this as naïve; they would say that war is war, that when you're in it you fight with every means you have, or go down in defeat. But if that is the case, then there rests upon Western civilization, bitter as this may be, the obligation to be militarily stronger than its adversaries by a margin sufficient to enable it to dispense with those means which can stave off defeat only at the cost of undermining victory.

Fragments of Markham's notes
The Nemesis of Faith (1849)
Context: The conviction of the martyr that the stake is the gate of Paradise, diminishes the dignity of the suffering in proportion to its strength. If it be absolute certainty, the trial is absolutely nothing. And that all-wise Being who knew all, who himself willed, erected, determined all, what could the worst earthly suffering he to him to whom all the gates which close our knowledge were shining crystal? What trial, what difficulty was it all to him? His temptation is a mockery. His patience, meekness, humility, it is but trifling with words, unless he was a man, and but a man.
And yet what does it not say on the other side for mankind, that the life of one good man, which had nothing, nothing but its goodness to recommend it, should have struck so deep into the heart of the race that for eighteen hundred years they have seen in that life something so far above them that they will not claim a kindred origin with him who lived it. And while they have scarcely bettered in their own practice, yet stand, and ever since have stood, self-condemned, in acknowledging in spite of themselves that such goodness alone is divine.

Part 4, 1979 - 1984 "Welcome to the 1980's", p. 322
Memoirs (1993)

Turner v. Railton (1796), 2 Esp. 475.

Source: One-Dimensional Man (1964), pp. 145-146

George Boole, An Investigation of the Laws of Thought (1854) Ch. 13. Clarke and Spinoza, pp. 216-217. https://books.google.com/books?id=DqwAAAAAcAAJ&pg=PA216
A - F

Hays translation
V, 7
Meditations (c. 121–180 AD), Book V