“Love is merely a madness.”

“Love is merely a madness; and, I tell you, deserves as well a dark house and a whip as madmen do; and the reason why they are not so punish'd and cured is that the lunacy is so
ordinary that the whippers are in love too.”

William Shakespeare As You Like It

“When love is not madness it is not love.”

Pedro Calderón de la Barca (1600–1681) Spanish dramatist

“There is always some madness in love. But there is also always some reason in madness.”

Friedrich Nietzsche (1844–1900) German philosopher, poet, composer, cultural critic, and classical philologist

“If this be not love, it is madness, and then it is pardonable.”

William Congreve The Old Bachelor

“True, we love life, not because we are used to living, but because we are used to loving. There is always some madness in love, but there is also always some reason in madness.”

Friedrich Nietzsche (1844–1900) German philosopher, poet, composer, cultural critic, and classical philologist

“To say that war is madness is like saying that sex is madness: true enough, from the standpoint of a stateless eunuch, but merely a provocative epigram for those who must make their arrangements in the world as given.”

John Updike (1932–2009) American novelist, poet, short story writer, art critic, and literary critic

“…the madness of love is the greatest of heaven's blessings…”

Plato book Phaedrus

“Misery loves company, and madness calls it forth.”

Yann Martel book Life of Pi

“My wish is that you may be loved to the point of madness.”

André Breton (1896–1966) French writer