The Moon is a Harsh Mistress

The Moon Is a Harsh Mistress

Cover of the first edition
Author	Robert A. Heinlein
Cover artist	Irv Docktor
Country	United States
Language	English
Genre	Science fiction
Publisher	G. P. Putnam's Sons
Publication date	1966
Media type	Print (hardback & paperback)
Pages	382 (1997 Orb books softcover ed.)
ISBN	(1997 Orb books softcover ed.)
OCLC	37336037
Preceded by	The Rolling Stones (shared character)

The Moon Is a Harsh Mistress is a 1966 science fiction novel by American writer Robert A. Heinlein, about a Lunar colony's revolt against rule from Earth. The novel expresses and discusses libertarian ideals. It is respected for its credible presentation of a comprehensively imagined future human society on both the Earth and the moon.

Originally serialized in Worlds of If (December 1965, January, February, March, April 1966), the book was nominated for the Nebula Award in 1966. It received the Hugo Award for best science fiction novel in 1967.

At the time of the story, 2075, the Moon (Luna) is used as a penal colony by Earth's government, with the inhabitants living in underground cities. Most inhabitants (called "Loonies") are criminals, political exiles, or descendants thereof. The total population is about three million, with men outnumbering women two to one, so that polyandry is the norm. Although Earth's Protector of the Lunar Colonies (called the "Warden") holds power, in practice there is little intervention in the loose Lunar society.

HOLMES IV ("High-Optional, Logical, Multi-Evaluating Supervisor, Mark IV") is the Lunar Authority's master computer, having almost total control of Luna's machinery on the grounds that a single computer is cheaper than (though not as safe as) multiple independent systems.

The story is narrated by Manuel Garcia "Mannie" O'Kelly-Davis, a computer technician who discovers that HOLMES IV has achieved self-awareness and has developed a sense of humor. Mannie names it "Mike" after Mycroft Holmes, brother of Sherlock Holmes, and they become friends.

At the beginning of the story, Mannie, at Mike's request, places a recorder in an anti-Authority meeting. When the authorities raid the gathering, Mannie flees with Wyoming ("Wyoh") Knott, a political agitator, whom he introduces to Mike and with whom he meets his former teacher, the elderly Professor Bernardo de la Paz, who claims that Luna must stop exporting hydroponic wheat to Earth or its limited water resources will be exhausted. In connection with this, Mike calculates that if no prevention occurs, there will be food riots in seven years and cannibalism in nine. Wyoh and the Professor decide to start a revolution, which Mannie is persuaded to join after Mike calculates that it has a 1 in 7 chance of success.