Man is an intelligence, not served by, but in servitude to his organs. Aldous Huxley, "Themes and Variations"
Man is but a reed, the most feeble thing in nature; but he is a thinking reed. The entire universe need not arm itself to crush him. A vapour, a drop of water suffices to kill him. But, if the Universe were to crush him, man would still be more noble than that which killed him, because he knows that he dies and the advantage which the universe has over him; the universe knows nothing of this. Blaise Pascal, "Pensées"
Man is not made for defeat. A man can be destroyed but not defeated. Ernest Hemingway, "The Old Man and The Sea"
Man is not man, but a wolf to those he does not know. Titus Maccius Plautus, "The Comedy of Asses"
Man is so made that he can only find relaxation from one kind of labor by taking up another. Anatol France, "The Crime of Sylvestre Bonnard"
Man is the one who desires, woman the one who is desired. This is woman's entire but decisive advantage. Through man's passions, nature has given man into woman's hands, and the woman who does not know how to make him her subject, her slave, her toy, and how to betray him with a smile in the end is not wise. Leopold Von Sacher-Masoch, "Venus in Furs"
Man must choose whether to be rich in things or in the freedom to use them. Ivan Illich, "Deschooling Society"