“Had Mephistopheles conferred no other service on Faust than easing him for a while of his cloak of learning, the doctor would have had little cause for despair. But the act of awaking is regulated by different principles from those which govern the act of going to sleep. In the former case, the hand of force is often necessary. Life points out with an iron staff the path which each individual should follow. Happy is the man who sees this staff, and follows the path; instead of tarrying by the way until weary, and, incapable of further exertion, he sinks bleeding to the ground. A high degree of mental culture, or a delicate tact, possessed by few, are required to distinguish the necessity of earnestness, or even of pain, in the midst of enjoyment.”

Source: A Brief History of Time (1988), Ch. 2

Keynote: Excerpts from his speeches and chairman's statements to shareholders

Source: Reflections on Violence (1908), p. 108

Source: Hilkhot De'ot (Laws Concerning Character Traits), Chapter 6, Section 1

Source: Human, All Too Human

Source: The Prince (1513), Ch. 6; translated by Luigi Ricci

Source: Brida

Source: Memoirs of Hadrian

Source: 1930s, Sex and Temperament in Three Primitive Societies (1935), p. 321