— Ralph Waldo Emerson American philosopher, essayist, and poet 1803 - 1882
— Stephen Fry English comedian, actor, writer, presenter, and activist 1957
— Robert A. Heinlein, Stranger in a Strange Land
"Jubal Harshaw" in the first edition (1961); the later 1991 "Uncut" edition didn't have this line, because it was one Heinlein had added when he went through and trimmed the originally submitted manuscript on which the "Uncut" edition is based. Heinlein also later used a variant of this in The Cat Who Walks Through Walls where he has Xia quote Harshaw: "Dr. Harshaw says that 'the word "love" designates a subjective condition in which the welfare and happiness of another person are essential to one's own happiness.'"
— Whitney Houston, Whitney the Greatest Hits
— Eleanor Roosevelt American politician, diplomat, and activist, and First Lady of the United States 1884 - 1962
— Aristotle Classical Greek philosopher, student of Plato and founder of Western philosophy -384 - -322 v.Chr
— Groucho Marx American comedian 1890 - 1977
„It is said that if you know your enemies and know yourself, you will not be imperiled in a hundred battles; if you do not know your enemies but do know yourself, you will win one and lose one; if you do not know your enemies nor yourself, you will be imperiled in every single battle.“
— Sun Tzu ancient Chinese military general, strategist and philosopher from the Zhou Dynasty -543 - 251 v.Chr
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 thy enemy but not 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.
„Accustom yourself to look first to the dreadful consequences of failure; then fix your eye on the glorious prize which is before you; and when your strength begins to fail, and your spirits are well nigh exhausted, let the animating view rekindle your resolution, and call forth in renewed vigour the fainting energies of your soul.“
— William Wilberforce English politician 1759 - 1833
— Bob Marley Jamaican singer, songwriter, musician 1945 - 1981
„Serious tweet: we all must learn to be happy with being alone; that is when things begin to change.“
— Тайлер Джозеф American singer-songwriter and record producer 1988