“Know, my son, that the enemy will always be with you. He will be in the shadow of your dreams and in your living flesh, for he is the other part of yourself.”
Source: The Devil's Arithmetic (1988), p. 143
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Jane Yolen 28
American speculative fiction and children's writer 1939Related quotes

Variant translations
If you know others and know yourself, you will not be imperiled in a hundred battles; if you do not know others but know yourself, you win one and lose one; if you do not know others and do not know yourself, you will be imperiled in every single battle.
Know your enemy and know yourself, find naught in fear for 100 battles. Know yourself but not your enemy, find level of loss and victory. Know not thy enemy nor yourself, wallow in defeat every time.
Literal translation: Know [the] other, know [the] self, hundred battles without danger; not knowing [the] other but know [the] self, one win one loss; not knowing [the] other, not knowing [the] self, every battle must [be] lost.
Source: The Art of War, Chapter III · Strategic Attack

"If You Can't Sleep".
Volume Two (2010)

Source: Dark Age (2019), Ch. 35: Endure; Virginia, in a recorded message to Darrow

1990s, Long Walk to Freedom (1995)