Robert A. Heinlein on Love

"Jealousy is a disease, love is a healthy condition. The immature mind often mistakes one for the other, or assumes that the greater the love, the greater the jealousy - in fact, they are almost incompatible; one emotion hardly leaves room for the other."

"Love is the condition in which the happiness of another person is essential to your own."

"Aside from mathematics, just two things worth doing—kill a man and love a woman. He had done both; he was rich."

"I looked it up later; he was right. Dad is an absolute mine of useless information. He says a fact should be loved for itself alone."

"Babies are fun. And they’re not much trouble. Feed ‘em occasionally, help them when they need it, and love them a lot. That’s all there is to it."

"I am forced to conclude that being right has little to do with holding a woman’s affections."

"He had the high degree of courage so common in the human race, a race capable of conceiving death, yet able to face its probability daily, on the highway, on the obstetrics table, on the battlefield, in the air, in the subway—and to face lightheartedly the certainty of death in the end."

"See how involved it gets? Clover, bees, nitrogen, escape speed, power, plant-animal balance, gas laws, compound interest laws, meteorology—a mathematical ecologist has to think of everything and think of it ahead of time. Ecology is explosive; what seems like a minor and harmless invasion can change the whole balance."