Methuselah's Children is a science fiction novel by Robert A. Heinlein, originally serialized in Astounding Science Fiction in the July, August, and September 1941 issues. It was expanded into a full-length novel in 1958.
The novel is usually considered to be part of Heinlein's "Future History" series of stories. It introduces the Howard Families, a fictional group of people who achieved long lifespans through selective breeding. The space ship in this novel, the New Frontiers, is described in the Future History timeline as a second generation ship, following the Vanguard, the vehicle for Heinlein's paired novellas "Universe" and "Common Sense".
According to John W. Campbell, the novel was originally to be called While the Evil Days Come Not. This provisional title stems from a quotation from Ecclesiastes that was used as a password on the second page of the story.
The Howard Families derive from Ira Howard, who became rich in the California Gold Rush, but died young and childless. The trustees of his will carried out his wishes to prolong human life by financially rewarding those with long-lived grandparents, who married each other and had children. By the 22nd Century, these families have a life expectancy of 150 years, and have kept their existence secret, but reveal themselves to the society established under The Covenant, which refuses to believe that the Howard Families obtained their lifespan by selective breeding, instead insisting they have developed a secret method to extend life. Though the Administrator of the planet, Slayton Ford, is convinced the Families are telling the truth, he cannot prevent efforts to force the Howard Families to reveal their (non-existent) rejuvenatory abilities.
Therefore protagonist Lazarus Long, the eldest member of the Howard Families, proposes to the Administrator that the Families hijack the colony starship New Frontiers, to leave Earth. Combining this with a device that removes inertia from any mass, invented by Andrew Jackson "Slipstick" Libby (a member of the Families), the Families leave the Solar System, with the deposed Ford. The first planet they discover has humanoid inhabitants domesticated by indescribable godlike natives. When Earthly humans prove incapable of similar domestication, they are expelled from the planet to another world.
The second planet is a lush environment with no predators and mild weather. Its inhabitants are part of a group mind, with the mental ability to manipulate the environment on the genetic and molecular level, but do not distinguish between individuals. This becomes evident when Mary Sperling, second oldest of the Families, joins the group mind to become immortal. The Families are further horrified when the group mind genetically modifies the first baby born on the planet into a new, alien form, and a majority of the Families return to Earth to claim their liberty; whereupon Libby, with the help of the group mind, builds a new faster than light drive to take them home in months instead of years. The Families return to the Solar System seventy-five years after their original departure, and discover that Earth's scientists have artificially extended human lifespans to several centuries. The Families are now welcomed for their discovery of travel faster than light. Libby and Long decide to recruit other members of the Families, and explore space with the new drive.
- Masquerade: The term "Masquerade" is used in the story as the code-name which the extremely long-lived Howard Families apply to their efforts to conceal their longevity. The novel starts with the consequences of an attempt to drop the Masquerade - which has gone badly.
- As You Know: The novel opens with a meeting of Howard Foundation members where one character goes on for several pages, detailing the history of the foundation, its goals, and his plans for the future. While very interesting (to the reader), the entire monologue is framed as an As You Know. As the characters are all extremely long-lived and therefore very patient, they don't mind too much. (He is, however, called on it by Lazarus Long, who has better things to do - mostly involving sex.)
- Generation Ships: The New Frontiers was a Generation Ship which was later upgraded with a FTL Drive.
- Go Mad from the Revelation / These Are Things Man Was Not Meant to Know: Slayton Ford goes mad when he meets the Sufficiently Advanced Aliens. Interestingly, after Ford goes mad, Lazarus Long mentions he is afraid that if he met them he wouldn't go mad.
- Stone Soup: Lazarus Long carries out the "form a committee to get all the idiots out of the way" version.
- Sufficiently Advanced Aliens: On the second planet the Howard Families visit, as mentioned above.
- Undead Tax Exemption: The problems with getting legal IDs that match assumed ages are mentioned as one reason why the long-lived Howard Family members are attempting to see if they can end their Masquerade.