“You can have peace. Or you can have freedom. Don't ever count on having both at once.”

American science fiction author, engineer, and naval officer

Robert A. Heinlein was an American science fiction author, engineer, and naval officer. He is known as a major figure in twentieth-century science fiction, and is sometimes called the “dean of science fiction writers.” He was among the first writers to stress scientific accuracy in fiction, helping shape hard science fiction. His fiction and nonfiction often praise competence, encourage critical thinking, and place characters in situations that test conventional social values. His influence remains visible in the genre and in wider culture.