I. The Foundation books have long been regarded as Asimov's best contribution to science fiction. The work was conceived by Asimov as the science-fiction equivalent of Gibbon's Decline and Fall of the Roman Empire. The first stories began appearing in Astounding Science Fiction in 1942 and continued regularly. In the early 1950s they were published as three novels (#3,4,5) which became known collectively as the Foundation Trilogy. A three-volume omnibus edition was published by Doubleday in 1964. The connecting thread in the series is Hari Seldon's invention of the science of "psychohistory" which enables the founders of the First and Second Foundations to predict and manipulate the future. Asimov lost interest in the series but, after a hiatus of thirty years, was persuaded to return in 1982 because his publisher, Doubleday,"got tired of waiting and offered me five-figure (and then six-figure) advances to write more" (personal communication). The new Foundation volumes have been best-sellers and have won Asimov a new generation of fans. In his later work Asimov created connecting links which tie together his science-fiction output in one large Galactic Empire scheme. The later volumes of the Robot series (II below) are linked to the Foundation novels. There are also three novels published in the 1950s which are set in the same universe, when the Empire was at its height: Pebble in the Sky(Doubleday, 1950); The Stars Like Dust (Doubleday, 1951); The Currents of Space(Doubleday, 1952). Greg Bear (q.v.), Gregory Benford (q.v.), and David Brin (q.v.) have recently added a new Foundation trilogy.

1. Prelude to Foundation (Doubleday, 1988)
This prequel relates the adventures of Hari Seldon, inventor of "psychohistory" and the Seldon Plan, during the reign of Galactic Emperor Cleon.

2. Forward the Foundation (Doubleday, 1993)
This posthumously published volume of the series relates the adult years of Hari Seldon, creator of the Seldon Plan.

3. Foundation (Gnome, 1951)
The First Foundation, consisting of physical scientists, is set up on Terminus, a planet on the outer fringes of a decaying Galactic Empire. Abridged variant: The Thousand Year Plan.

4. Foundation and Empire (Gnome, 1952)
A threat to the Seldon Plan arrives in the person of the Mule, a mutant not predicted by "psychohistory." Variant title: The Man Who Upset the Universe.

5. Second Foundation (Gnome, 1953)
The First Foundation and the Mule search for the secret Second Foundation, which is composed of psychologist who can mentally tamper with, and "adjust" individuals.

6. Foundation's Edge (Doubleday, 1982)
Several hundred years later, the First and Second Foundations are jockeying for power as facilitators of the Seldon Plan.

7. Foundation and Earth (Doubleday, 1986)
Having second thoughts about the momentous decision he made in Foundation's Edge, Golan Trevize goes in search of "Earth", the legendary mother-planet.

II. Asimov was also the creator of the Positronic Robot and a series of more than thirty robot short stories published over a span of nearly forty years. The short stories are collected in The Complete Robot (Doubleday, 1982). He also wrote a series of novels about an interstellar police detective named Elijah Baley and his robot partner Daneel Olivaw. The first three novels are a very successful hybrid o the science-fiction and detective story genres. In the fourth novel, Robots and Empire, Asimov explicitly links this series with the Foundation Series (I above).

Note: Roger MacBride Allen (q.v.) used Asimov's idea of a rogue robot to create a trilogy of novels.

1. Caves of Steel, The (Doubleday, 1954)
Human detective Elijah Baley, a resident of the despised planet Earth, is linked up with robot detective R. Daneel Olivaw to solve the murder of Dr. Sarton.

2. Naked Sun, The (Doubleday, 1957)
Baley and Olivaw are sent to the planet Solaria to solve another murder.

3. Robots of Dawn, The (Doubleday, 1983)
The detective pair travel to Daneel's home planet, Aurora, in order to help clear the name of his creator, Dr. Fastolfe.

4. Robots and Empire (Doubleday, 1985)
Daneel aids the Settler descendants of Elijah Baley in thwarting the Spacer's plan to burn up the Earth's crust.