“Now the entire herd had begun to wheel wider and faster along the bluff and the outermost ranks swung centrifugally over the escarpment row on row wailing and squealing and above this the howls and curses of the drovers that now upreared in the moil of flesh they tended and swept with dust had begun to assume satanic looks with their staves and wild eyes as if they were no true swineheards but disciples of darkness got among these charges to herd them to their doom.”

Variant translation: The only way to truly know a person is to argue with them. For when they argue in full swing, then they reveal their true character.
28 September 1942
Variant: I've learned one thing: you only really get to know a person after a fight. Only then can you judge their true character!
Source: The Diary of a Young Girl (1942 - 1944)

Though they lay flat the mountains and dry up the sea, Wilt thou yet change, as though God were a god?
Pilgrim’s Regress 186–187
The Pilgrim's Regress (1933)

1980s–1990s, Barbarians inside the Gates and Other Controversial Essays (1999)

"The Knight, Death and the Devil," lines 17-20
The Seven-League Crutches (1951)
Context: His eye a ring inside a ring inside a ring
That leers up, joyless, vile, in meek obscenity —
This is the devil. Flesh to flesh, he bleats
The herd back to the pit of being.

Source: Argonautica (3rd century BC), Book IV. Homeward Bound, Lines 933–938 (tr. R. C. Seaton)

“The Brilliant Epoch” http://www.schulzian.net/translation/sanatorium/epoch1.htm
His father, Living things

Source: The Revolt of the Angels (1914), Ch. XXXV
Context: Satan found pleasure in praise and in the exercise of his grace; he loved to hear his wisdom and his power belauded. He listened with joy to the canticles of the cherubim who celebrated his good deeds, and he took no pleasure in listening to Nectaire's flute, because it celebrated nature's self, yielded to the insect and to the blade of grass their share of power and love, and counselled happiness and freedom. Satan, whose flesh had crept, in days gone by, at the idea that suffering prevailed in the world, now felt himself inaccessible to pity. He regarded suffering and death as the happy results of omnipotence and sovereign kindness. And the savour of the blood of victims rose upward towards him like sweet incense. He fell to condemning intelligence and to hating curiosity. He himself refused to learn anything more, for fear that in acquiring fresh knowledge he might let it be seen that he had not known everything at the very outset. He took pleasure in mystery, and believing that he would seem less great by being understood, he affected to be unintelligible. Dense fumes of Theology filled his brain. One day, following the example of his predecessor, he conceived the notion of proclaiming himself one god in three persons. Seeing Arcade smile as this proclamation was made, he drove him from his presence. Istar and Zita had long since returned to earth. Thus centuries passed like seconds. Now, one day, from the altitude of his throne, he plunged his gaze into the depths of the pit and saw Ialdabaoth in the Gehenna where he himself had long lain enchained. Amid the ever lasting gloom Ialdabaoth still retained his lofty mien. Blackened and shattered, terrible and sublime, he glanced upwards at the palace of the King of Heaven with a look of proud disdain, then turned away his head. And the new god, as he looked upon his foe, beheld the light of intelligence and love pass across his sorrow-stricken countenance. And lo! Ialdabaoth was now contemplating the Earth and, seeing it sunk in wickedness and suffering, he began to foster thoughts of kindliness in his heart. On a sudden he rose up, and beating the ether with his mighty arms, as though with oars, he hastened thither to instruct and to console mankind. Already his vast shadow shed upon the unhappy planet a shade soft as a night of love.
And Satan awoke bathed in an icy sweat.
Nectaire, Istar, Arcade, and Zita were standing round him. The finches were singing.
"Comrades," said the great archangel, "no — we will not conquer the heavens. Enough to have the power. War engenders war, and victory defeat.
"God, conquered, will become Satan; Satan, conquering, will become God. May the fates spare me this terrible lot; I love the Hell which formed my genius. I love the Earth where I have done some good, if it be possible to do any good in this fearful world where beings live but by rapine.
Now, thanks to us, the god of old is dispossessed of his terrestrial empire, and every thinking being on this globe disdains him or knows him not. But what matter that men should be no longer submissive to Ialdabaoth if the spirit of Ialdabaoth is still in them; if they, like him, are jealous, violent, quarrelsome, and greedy, and the foes of the arts and of beauty? What matter that they have rejected the ferocious Demiurge, if they do not hearken to the friendly demons who teach all truths; to Dionysus, Apollo, and the Muses? As to ourselves, celestial spirits, sublime demons, we have destroyed Ialdabaoth, our Tyrant, if in ourselves we have destroyed Ignorance and Fear."
And Satan, turning to the gardener, said:
"Nectaire, you fought with me before the birth of the world. We were conquered because we failed to understand that Victory is a Spirit, and that it is in ourselves and in ourselves alone that we must attack and destroy Ialdabaoth."

As quoted in Zirkle, Conway (1935), The beginnings of plant hybridization p. 105