More quotes by Robert A. Heinlein

"Anyone who cannot cope with mathematics is not fully human. At best, he is a tolerable subhuman who has learned to wear his shoes, bathe, and not make messes in the house."
"Love is that condition in which the happiness of another person is essential to your own... 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."
"Women and cats will do as they please, and men and dogs should relax and get used to the idea."
"An armed society is a polite society. Manners are good when one may have to back up his acts with his life."
"May you live as long as you wish and love as long as you live."