This is sometimes attributed to Sun Tzu in combination with the above quote, as well as alone, but it too has not been sourced to any published translation of The Art of War, though it is similar in concept to his famous statement in Ch. 3 : "It is said that if you know your enemies and know yourself, you will not be imperiled in a hundred battles..."
Misattributed
1990s, Long Walk to Freedom (1995)
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
1950s, Loving Your Enemies (November 1957)
Context: Another way that you love your enemy is this: When the opportunity presents itself for you to defeat your enemy, that is the time which you must not do it. There will come a time, in many instances, when the person who hates you most, the person who has misused you most, the person who has gossiped about you most, the person who has spread false rumors about you most, there will come a time when you will have an opportunity to defeat that person. It might be in terms of a recommendation for a job; it might be in terms of helping that person to make some move in life. That’s the time you must not do it.
“If you have an enemy, then learn and know your enemy, don't just be mad at him or her”
Source: The Goblin Quest Series, Goblin Hero (2007), Chapter 7 (p. 117)
“In order to love your enemies, you must begin by analyzing self.”
1950s, Loving Your Enemies (November 1957)
Context: How do you go about loving your enemies? I think the first thing is this: In order to love your enemies, you must begin by analyzing self. And I’m sure that seems strange to you, that I start out telling you this morning that you love your enemies by beginning with a look at self. It seems to me that that is the first and foremost way to come to an adequate discovery to the how of this situation. … some people aren’t going to like you. They’re going to dislike you, not because of something that you’ve done to them, but because of various jealous reactions and other reactions that are so prevalent in human nature. But after looking at these things and admitting these things, we must face the fact that an individual might dislike us because of something that we’ve done deep down in the past, some personality attribute that we possess, something that we’ve done deep down in the past and we’ve forgotten about it; but it was that something that aroused the hate response within the individual. That is why I say, begin with yourself. There might be something within you that arouses the tragic hate response in the other individual.
