Robert A. Heinlein book Space Cadet
Source: Space Cadet (1948), Chapter 6 “Reading, and ’riting, and ’rithmetic—”, p. 71
Robert Anson Heinlein was an American science fiction writer. Often called the "dean of science fiction writers", his sometimes controversial works continue to have an influential effect on the genre, and on modern culture more generally.
Heinlein became one of the first American science fiction writers to break into mainstream magazines such as The Saturday Evening Post in the late 1940s. He was one of the best-selling science fiction novelists for many decades, and he, Isaac Asimov, and Arthur C. Clarke are often considered the "Big Three" of English-language science fiction authors. Among his most notable works are Stranger in a Strange Land, Starship Troopers, which helped create the space marine and mecha archetypes, and the libertarian novel The Moon is a Harsh Mistress.
A writer also of numerous science fiction short stories, Heinlein was one of a group of writers who came to prominence under the editorship of John W. Campbell at his Astounding Science Fiction magazine; however, Heinlein denied that Campbell influenced his writing to any great degree.
Within the framework of his science fiction stories, Heinlein repeatedly addressed certain social themes: the importance of individual liberty and self-reliance, the obligation individuals owe to their societies, the influence of organized religion on culture and government, and the tendency of society to repress nonconformist thought. He also speculated on the influence of space travel on human cultural practices.
Heinlein was named the first Science Fiction Writers Grand Master in 1974. He won Hugo Awards for four of his novels; in addition, fifty years after publication, five of his works were awarded "Retro Hugos"—awards given retrospectively for works that were published before the Hugo Awards came into existence. In his fiction, Heinlein coined terms that have become part of the English language, including "grok", "waldo", and "speculative fiction", as well as popularizing existing terms like "TANSTAAFL", "pay it forward", and "space marine". He also anticipated mechanical computer aided design with "Drafting Dan" and described a modern version of a waterbed in his novel The Door into Summer, though he never patented or built one. In the first chapter of the novel Space Cadet he anticipated the cell-phone, 35 years before Motorola invented the technology. Several of Heinlein's works have been adapted for film and television.

Robert A. Heinlein book Space Cadet
Source: Space Cadet (1948), Chapter 6 “Reading, and ’riting, and ’rithmetic—”, p. 71
Behaving on a still higher moral level were the astronauts who went to the Moon, for their actions tend toward the survival of the entire race of mankind. The door they opened leads to the hope that H. sapiens will survive indefinitely long, even longer than this solid planet on which we stand tonight. As a direct result of what they did, it is now possible that the human race will never die.
Many short-sighted fools think that going to the Moon was just a stunt. But the astronauts knew the meaning of what they were doing, as is shown by Neil Armstrong's first words in stepping down onto the soil of Luna: "One small step for a man, one giant leap for mankind."
The Pragmatics of Patriotism (1973)
“Marriage is not ownership and wives are not property.”
Robert A. Heinlein book The Puppet Masters
Source: The Puppet Masters (1951), Chapter 21 (p. 116)
Robert A. Heinlein book Methuselah's Children
Methuselah's Children (1958)
Robert A. Heinlein book Red Planet
“Yes, sir. I think I do.”
Source: Red Planet (1949), Chapter 2, “South Colony, Mars”, pp. 16-17
"The Discovery of the Future," Guest of Honor Speech, 3rd World Science Fiction Convention, Denver, Colorado (4 July 1941)
Robert A. Heinlein book The Rolling Stones
“And not very good poetry.”
Source: The Rolling Stones (1952), Chapter 14, “Flat Cats Factorial” (p. 182)
Robert A. Heinlein book Between Planets
Source: Between Planets (1951), Chapter 17, “To Reset the Clock” (p. 173)
Robert A. Heinlein book The Puppet Masters
Source: The Puppet Masters (1951), Chapter 19 (p. 104)
Robert A. Heinlein book Red Planet
Source: Red Planet (1949), Chapter 4, “Lowell Academy”, p. 44
Robert A. Heinlein book I Will Fear No Evil
Source: I Will Fear No Evil (1970), Chapter 27, p. 488
“The sort of guardian you can hire is worth about as much as the sort of wife you can buy.”
Robert A. Heinlein book Space Cadet
Source: Space Cadet (1948), Chapter 12 “P.R.S. Pathfinder”, p. 143
Robert A. Heinlein book To Sail Beyond the Sunset
Source: To Sail Beyond the Sunset (1987), p. 370 (Ace 1988)
Robert A. Heinlein book Farmer in the Sky
Source: Farmer in the Sky (1950), Chapter 9, “The Moons of Jupiter” (pp. 90-91)
Robert A. Heinlein book Beyond This Horizon
This offhand mention has become the simplest (three words!) and often-quoted exposition of the wonders of a different world, where what would be novel today has become simply the way things work.
Source: Beyond This Horizon (1948; originally serialized in 1942), Chapter 1, “All of them should have been very happy—”, p. 5 and several other times
“Women seem to have almost unlimited capacity for forgiveness.”
Robert A. Heinlein book The Cat Who Walks Through Walls
Since it is usually a man who needs forgiveness, this must be a racial survival trait.
Richard Ames; chapter 16, p. 200
The Cat Who Walks Through Walls (1985)
“Rod…were you born that stupid? Or did you have to study?”
Robert A. Heinlein book Tunnel in the Sky
Source: Tunnel in the Sky (1955), Chapter 6, “I Think He Is Dead” (p. 104)
Robert A. Heinlein book Tunnel in the Sky
Source: Tunnel in the Sky (1955), Chapter 2, “The Fifth Way” (p. 43)
Robert A. Heinlein book Tunnel in the Sky
Source: Tunnel in the Sky (1955), Chapter 2, “The Fifth Way” (p. 42)
“Fact is, you work too hard…the universe won’t run down if you don’t wind it.”
Robert A. Heinlein book The Star Beast
Source: The Star Beast (1954), Chapter 12, “Concerning Pidgie-Widgie” (p. 185)
“I do not like weapons, Doctor; they are the last resort of faulty diplomacy.”
Robert A. Heinlein book The Star Beast
Source: The Star Beast (1954), Chapter 9, “Customs and an Ugly Duckling” (p. 151)
“If you can’t outargue the other fellow, sometimes you can outlive him.”
Robert A. Heinlein book The Star Beast
Source: The Star Beast (1954), Chapter 6, “Space is Deep, Excellency” (p. 110)
“Funny sort of science! I guess they were pretty ignorant in those days.”
“Don’t go running down our grandfathers. If it weren’t for them, you and I would be squatting in a cave, scratching fleas. No, Bub, they were pretty sharp; they just didn’t have all the facts. We’ve got more facts, but that doesn’t make us smarter.”
A Tenderfoot in Space (p. 691)
Short fiction, Off the Main Sequence (2005)
A Tenderfoot in Space (p. 689)
Short fiction, Off the Main Sequence (2005)
Robert A. Heinlein book The Year of the Jackpot
The Year of the Jackpot (p. 644)
Short fiction, Off the Main Sequence (2005)
Robert A. Heinlein book The Year of the Jackpot
The Year of the Jackpot (p. 628)
Short fiction, Off the Main Sequence (2005)
Robert A. Heinlein book Gulf
Gulf (p. 559)
Short fiction, Off the Main Sequence (2005)
Robert A. Heinlein book Gulf
Gulf (pp. 556-557)
Short fiction, Off the Main Sequence (2005)
“A totalitarian political religion is incompatible with free investigation.”
Robert A. Heinlein book Gulf
Gulf (p. 545)
Short fiction, Off the Main Sequence (2005)
Robert A. Heinlein book Gulf
Gulf (p. 544)
Short fiction, Off the Main Sequence (2005)
Robert A. Heinlein book Gulf
Gulf (p. 544)
Short fiction, Off the Main Sequence (2005)
Robert A. Heinlein book Goldfish Bowl
Goldfish Bowl (p. 381)
Short fiction, Off the Main Sequence (2005)
“For vice has this defect; it cannot be truly intelligent. Its very motives are its weakness.”
Robert A. Heinlein book Lost Legacy
Lost Legacy (p. 339)
Short fiction, Off the Main Sequence (2005)
Robert A. Heinlein book Lost Legacy
Lost Legacy (p. 339)
Short fiction, Off the Main Sequence (2005)
“Cold calculated awareness that their power lay in keeping the people in ignorance.”
Robert A. Heinlein book Lost Legacy
Lost Legacy (p. 333)
Short fiction, Off the Main Sequence (2005)
Robert A. Heinlein book Lost Legacy
Lost Legacy (p. 301)
Short fiction, Off the Main Sequence (2005)
Robert A. Heinlein book Lost Legacy
Lost Legacy (p. 284)
Short fiction, Off the Main Sequence (2005)
Robert A. Heinlein book By His Bootstraps
By His Bootstraps (p. 257)
Short fiction, Off the Main Sequence (2005)
Robert A. Heinlein book By His Bootstraps
By His Bootstraps (p. 238)
Short fiction, Off the Main Sequence (2005)
Robert A. Heinlein book By His Bootstraps
By His Bootstraps (p. 234)
Short fiction, Off the Main Sequence (2005)
Robert A. Heinlein book Elsewhen
Elsewhen (p. 182)
Short fiction, Off the Main Sequence (2005)
Robert A. Heinlein book Elsewhen
Frost snorted. “I certainly do—if he has observed it with his own eyes and ears, or gets it from a source known to be credible. A fact doesn’t have to be understood to be true. Sure, any reasonable mind wants explanations, but it’s silly to reject facts that don’t fit your philosophy.”
Elsewhen (pp. 161-162)
Short fiction, Off the Main Sequence (2005)
“Imperialism degrades both oppressor and oppressed.”
Robert A. Heinlein book Solution Unsatisfactory
Solution Unsatisfactory (p. 98)
Short fiction, Off the Main Sequence (2005)
Robert A. Heinlein book Solution Unsatisfactory
Solution Unsatisfactory (p. 67)
Short fiction, Off the Main Sequence (2005)
Robert A. Heinlein book They
They (p. 60)
Short fiction, Off the Main Sequence (2005)
“Why do you like to play chess so well?”
Robert A. Heinlein book They
“Because it is the only thing in the world where I can see all the factors and understand all the rules.”
They (p. 55)
Short fiction, Off the Main Sequence (2005)
And He Built a Crooked House (p. 33)
Short fiction, Off the Main Sequence (2005)
“Yes, maybe it’s just one colossal big joke with no point to it.”
Robert A. Heinlein book Methuselah's Children
Lazarus stood up and stretched and scratched his ribs. “But I can tell you this, Andy, whatever the answers are, here’s one monkey that’s going to keep on climbing, and looking around him to see what he can see, as long as the tree holds out.”
Methuselah’s Children (p. 667; closing words)
Short fiction, The Past Through Tomorrow (1967)
“What course of action do you favor?”
Robert A. Heinlein book Methuselah's Children
“Me? Why, none. Mary, if there is any one thing I have learned in the past couple of centuries, it’s this: These things pass. Wars and depressions and Prophets and Covenants—they pass. The trick is to stay alive through them.”
Methuselah’s Children (p. 539)
Short fiction, The Past Through Tomorrow (1967)