The premise of the stories is that in the waning days of a still powerful Galactic Empire, the mathematician Hari Seldon spends his life developing a theory of psychohistory, a new and effective mathematics of sociology.
Although the momentum of the Empire's fall is too great to stop, Seldon devises a plan by which "the onrushing mass of events must be deflected just a little" to eventually limit this interregnum to just one thousand years.
[4] James E. Gunn wrote that though the series of lead characters Lathan Devers, Salvor Hardin, Limmar Ponyets and Hober Mallow "may seem interchangeable", they are "as differentiated as the personages in most histories.
[11] In the last chapter, Asimov uses the character of Barr to explain the political dynamics of why Riose would never have been able to defeat the Foundation: a strong emperor's sense of self-preservation would never allow him to tolerate a subordinate who develops potentially threatening power.
[13][14] In the 2023 episode "A Glimpse of Darkness", Barr witnesses a presentation on Siwenna by High Claric Poly Verisof and Brother Constant of the Church of the Galactic Spirit, extolling the virtues of the Foundation and Seldon's predictions.
Riose and Curr learn that the Foundation has provided the clarics with auras, protective force shield technology forbidden to everyone except the Emperors, and whisper-ships, a Foundation-created type of jumpship which can perform faster-than-light travel without requiring a Spacer to navigate.
[12] In the prequel novel Prelude to Foundation (1988), Emperor Cleon I learns of mathematician Hari Seldon's nascent concept of psychohistory, which might theoretically make it possible to predict the future.
[10]: 213–215 [17] Wimmer and Wilkens described Cleon as "basically decent but woefully inadequate" but also "a fairly entertaining character, who has me absolutely convinced that ruling a whole galaxy could be just a drag if you were born at the wrong time".
[20] Though cloning does not factor in Asimov's novels,[21][22] the television series introduces a "Genetic Dynasty", surreptitiously administered for centuries by the regal Lady Demerzel, secretly a unique, ageless robot.
"[16] They wrote, "It's remarkable just how perfectly Asimov captures the occasionally obnoxious precociousness of the gifted teenager ... but he also folds in Arkady's romanticism and femininity without ever making them seem silly or stereotypical.
The complacent Mayor Indbur of Terminus is nonplussed about the danger posed by the Mule, believing that the pending hologram from Hari Seldon will tell them how to handle this latest crisis.
[9][11] John Folk-Williams described Bayta as "the real star of this story, a fairly well realized female character who is considerably smarter and more observant than her young husband and who often carries the burden of explaining what's going on to her less aware companions."
[25] In Prelude to Foundation, reporter Chetter Hummin warns young mathematician Hari Seldon that his nascent theory of psychohistory has attracted the dangerous attention of Eto Demerzel, the First Minister and chief advisor to Emperor Cleon I. Pairing Seldon with Streeling University historian Dors Venabili, Hummin assists him in his danger-fraught tour of several of Trantor's 800 varied sectors, evading capture by Demerzel while gathering information he hopes will inform if and how psychohistory can be developed into a predictive science.
[10]: 213–215 James E. Gunn compared Seldon's revelation that Demerzel is a robot to the sequence in the 1933 novel Lost Horizon in which Hugh Conway guesses correctly that the High Lama is the 250-year-old monk Perrault.
[20] Rafael Motamayor of Vulture wrote, "Demerzel is Foundation's biggest secret weapon—a character the show is mostly keeping a mystery while slowly unraveling just how central to every aspect of the story she really is.
Knowing that Dornick is possibly the only person in the galaxy capable of fully understanding his work, Seldon reveals his prediction of the unavoidable and relatively imminent fall of the Galactic Empire.
[10]: 23–24 [28] Describing "The Psychohistorians" as "28 pages of nonstop world-building", Wimmer and Wilkins note that "the ostensible protagonist, Gaal Dornick, is such a non-entity that he barely even counts as an audience identification figure".
[9][11] Wimmer and Wilkins called Mis "the liveliest character of the series since Salvor Hardin", and described him as "so deliberately over-the-top—and so fun to read because of it ... he's like one of Heinlein's classic old men, Jubal Harshaw or Lazarus Long, with a heaping dash of comic outrageousness that wouldn't work in Stranger in a Strange Land or Time Enough for Love (they're too ponderous) but fits perfectly in the slightly cartoonish universe of the Foundation.
He is a mutant who can sense and manipulate the emotions of others, an ability he has employed to conquer planets bloodlessly, to "Convert" Foundation intelligence officer Han Pritcher into a loyal agent, and to compel Mis to work himself to death.
He dismisses Mayor Salvor Hardin's concerns about the Foundation's susceptibility to interference by nearby regimes, believing that their focus should be on creating the Encyclopedia Galactica and not local politics.
Asimov later explains the political dynamics of why Riose would never have been able to defeat the Foundation: a strong emperor's sense of self-preservation would never allow him to tolerate a subordinate who develops potentially threatening power.
[26][42] Introduced in Foundation in "The Psychohistorians", famed mathematician and psychologist Hari Seldon has developed the science of psychohistory, which uses sophisticated mathematics and statistical analysis to predict future trends on a galactic scale.
[10]: 23–24 [28] Describing "The Psychohistorians" as "28 pages of nonstop world-building", Wimmer and Wilkins wrote that in the story, "Hari Seldon isn't so much a character as he is the living embodiment of psychohistory, an ethereal presence who's about as relatable as Gandalf.
[44] Venabili begins an investigation centered on the Electro-Clarifier, a new device co-invented by Tamwile Elar and built by Cinda Moray, which enhances the abilities of Seldon's Prime Radiant.
[27][49] In the season two finale "Creation Myths", Mallow puts Constant in the only remaining escape pod of the doomed Imperial flagship Shining Destiny, and sends her to safety as he and General Bel Riose sacrifice themselves on the exploding ship.
[50] Jeffrey Speicher of Collider wrote that Constant's "straightforward, shoot-from-the-hip manner is one of the most fun and refreshing aspects of a mind-bending show that can sometimes feel a little overwhelming with the pure size and scope of the stories it takes on.
[53] Sean T. Collins of Decider praised Constant's "forthrightness and directness" in propositioning Mallow,[49] and Speicher agreed that her "straightforward and refreshing approach to expressing her feelings for Hober brings a natural and organic dynamic to [their] romantic storyline.
[26][42] In "Where the Stars are Scattered Thinly", Riose and Curr visit Imperial informant Ducem Barr on Siwenna and learn that the Foundation, and by extension their propagandists the Church of the Galactic Spirit, possess forbidden technology.
Afflicted with a rapidly escalating neurological disorder, he had planned to commit suicide to preserve his followers' devotion to his genius, while Dornick helped establish the Foundation on Terminus and Foss was to take the digital Seldon elsewhere.
[23][65] Lady Demerzel, an ageless robot and the real power behind the Imperial throne, schemes to be rid of Sareth and retain the Genetic Dynasty of Cleon clones she has administered for centuries.