These are the discrepancies in Asimov's future history. This is an incomplete list.

Within the Robot short stories[]

  • The Cold War - In "Let's Get Together", set in 2045, the Cold War is still happening, and is a major thing, possibly the only war left, as the sides have started calling themselves "us" and "them". Not only does this contradict the real world, but multiple other stories set in the universe, and taking place before this date, and in America, seem to not mention this at all.
    • Rationalization 1: "Let's Get Together" seems to almost imply, despite it being a large-scale conflict, the War was almost a game. Perhaps the stakes were not actually that high.
    • Rationalization 2: It could have stopped (as in the real world) or just got less important between the 1940s and the 2040s, and then rose to the foreground again.
    • Rationalizaton 3: The War could have been irrelevent to those at US Robots and Mechanical Men, although this is unlikely as they were one of the biggest corporations in the US, and "Let's Get Together" shows that positronic robots were being used in the war.
  • The Three Laws of Robotics - There are many contradictory explanations of exactly how the Three Laws operate. In "Runaround", where they are first introduced as the "Rules of Robotics", they are presented as strict laws ground into the core of a positronic brain, whereas in "Catch That Rabbit", the First Law is somehow altered during production, which according to "The Bicentennial Man", and also The Caves of Steel, should be impossible, as you would have to create a new type of positronic brain yourself to do this, which would take years - you can't just accidentally change it. There are also many other inconsistencies.
    • Rationalization 1: There are many editions of positronic brain or robot.
    • Rationalization 2: The nature of the Laws rapidly change over time across the short stories.
    • Rationalization 3: In The Robots of Dawn, "positronic potential" allows Daneel's Second Law to override his First Law, suggesting they are not so strict, and in The Naked Sun it is explained the Three Laws are just an expression of the true programming in normal English. This could suggest that although they are ground into robots in a more complex form, the Three Laws do not have strict rules and restrictions expressable, only certain things that are generally true.
  • The Regions - According to "The Evitable Conflict" and the interconnecting text of I, Robot, World War III occcured during the 1970s-80s, and Earth split into Regions, ending nationalism. However, this does not seem to be have happened in "Robot AL-76 Goes Astray".
    • Rationalization: This story is set before the War. However, US Robots and Mechanical Men, which appears in the story, was founded in 1982, specifically stated to be "just after" the War.
      • Rationalization: Earth is said to have gradually split into regions. As this was just after, it could still be in the process, with nationalism remaining for a short few years. But this does not work either, since the story is set in 2006.
        • Rationalization: Simple continuity error by Asimov.
  • Energy production on Earth - according to "Reason", Earth largely uses space stations beaming solar energy to Earth. By the time of Susan's interview in I, Robot, they are obsolete and abandoned. In Caves of Steel, Earth largely uses uranium reactors, other nuclear reactions are yet to be mastered, and solar stations are described as a theoretical possibility which is yet to be mastered after over a century of effort (with plans to build them inside Mercury's orbit). Robots and Empire has most worlds using fusion reactors, with Earth being the only world mostly using solar stations, which are stated to be a technology as old as practical fusion power. It only uses fusion to a very limited extent, and refuses to use fission power for any reason, which has been the case for thousands of years.

Within the Foundation series[]

  • Date of Year 0 GE - In the original Foundation book, Salvor Hardin references that they have had atomic power for 50,000 years. This would place 50 FE around 48,000 AD, and so the Galactic Era would begin around 36,000 AD. However, in Foundation's Edge, Golan Trevize says it is 22,000 years after interstellar travel begins; i.e., AD 24,000. This is 12,566 years after the founding of the Galactic Empire, which sets the Empire's foundation around the year AD 11,584 = 0 GE.
    • Rationalization: One of these characters is mistaken. It is probably Salvor, as Daneel (a robot who was alive before even 1 GE so probably would not have removed it from his memory, cannot forget) backs up Trevize's version of the dating by saying he is over 20,000 years old.
  • Date of Year 1 FE - Similar to the above. It is unclear whether year 1 of the Foundation Era corresponds with 12,067 GE, the date of the trial, or 12,069 GE, Seldon’s death. On the first page of the original Foundation book, Seldon’s birth (11,988) is said to correspond with -79 FE, which would make the date 12,067 GE, 1 FE. However, in Forward the Foundation, at the end it specifically places his death in 12,069, at 1 FE.
    • Rationalization: Both of these were taken from extracts from the Encyclopedia Galactica. Although both are taken from the 116th Edition, it is possible it was updated slightly (too small a change to warrant a new edition) after new evidence, or that slightly different versions disagree on the exact placement of 1 FE, being a thousand years before.
  • The Mule's Origin - Many quotes from Foundation and Empire suggest that the Mule was a freak because of his mental powers, on his home planet, and that he took a while to work out his abilities. He also assumes, when an "entire world" is modifiying emotions, that it is the Second Foundation. However, in Foundation's Edge, there is another world that can do this, that the Mule turns out to be from, called Gaia, throwing into confusion why he was an "outsider" there, and why he didn't know of his abilities.
    • Rationalization: The Mule escaped Gaia, it is said. Perhaps he left at a young age with a relative or ally who was already renegade, and moved to a different planet he grew up on. This wouldn't explain, however, why he was not aware of his mental abilities until a late age.
  • The Publicity of Hari's Predictions - Toward the end of Forward the Foundation, it appears to be common knowledge that Hari predicts the Fall of the Galactic Empire: "After all, here is a man who has spent his entire career fortelling the Fall of the Empire and all he can really point to are a few burned-out bulbs in the dome, an occasional glitch in public transport, a budget here or there - nothing very dramatic. However, when he pronounces this to the Commission of Public Safety nine years later at the beginning of the original Foundation, they are shocked, and this appears to be a prediction he has not publicly announced before.
  • Problems with Hari's life - In Foundation and Empire, Ducem Barr says this to General Bel Riose: "Hari Seldon was a scientist of the reign of the Emperor, Daluben IV. He was a psycho-historian; the last and greatest of them all. He once visited Siwenna, when Siwenna was a great commercial centre, rich in the arts and sciences." There are two large problems here:
    • Firstly, in Forward the Foundation, we see that for Hari's first eighteen years on Trantor, Cleon I ruled; for ten years after that, he lived in the time of the junta; and for at least a decade after that Agis XIV was Emperor. By the time of Hari's trial, as we see in Foundation and Chaos, the (puppet) Emperor has been Klayus I for two years, and he was followed in the two years until Hari's death by Semrin according to Foundation's Triumph. Therefore, the only room for a Daluben IV in Hari's life is between Agis XIV and Klayus I, between whose reigns there is only a seven year gap. Therefore, it is extremely odd that Barr would refer to Seldon as a scientist of Daluben's reign, when he only ruled for an extremely small portion of his life, and a period in which he didn't even do anything notable, at that.
    • The second problem is Ducem's statement that Hari once visited Siwenna. According to Prelude to Foundation, Hari was born on Helicon and the first time he left home was when he left for the Decennial Mathematics Convention on Trantor at thirty-two. In the first part of Forward the Foundation, we then see that Hari stays on Trantor for eight more years, before leaving for Pengia and then Sark in Foundation's Fear. After Sark, he returns to Trantor and stays there throughout the rest of Forward the Foundation - until he is 80, in Foundation's Triumph, when he does leave the planet, but only for Demarchia, Pengia and then Earth, before going forward in time with Daneel, then returning to Trantor and dying. At not one point in his life does he even come close to Siwenna.
      • Rationalization: It is almost certainly true that in the 150 years since Seldon's death, as a famous figure in the Periphery and slowly becoming one in the entire Galaxy, legends and rumors sprung up about him, and plenty of false information about his life. Siwenna could easily have spread the myth that Seldon once visited it just to gain attraction, even if Seldon never actually travelled there.
  • Knowledge of Robots - In Foundation and Empire, Chapter 3, General Bel Riose casually mentions robots to Ducem Barr: "You are trying to say that I am a silly robot following a predetermined course into destruction." Riose, just an Imperial General, not a historian or scholar, has knowledge of robots. It is true that Riose could have happened to come across the word somewhere, but if it were anything obscure Riose would feel the need to explain the word to Barr - who does not ask what it means. Therefore, all of this paints a picture that robots are common knowledge. But in Foundation's Edge, Janov Pelorat, who has been a historian for decades, has never even heard the word "robot", nor has Foundation Councilman Golan Trevize.
  • Nature of the Second Foundationers - In Second Foundation, it is directly stated that the Second Foundationers are not actually telepathic as the Mule, but "deduce" people's thoughts by carefully reading their body language. They have also been trained to do this, rather than it being an inherent trait. "The First Speaker could not sense the emotional content of the Student's [mind] instinctively, as the Mule would have been able to do - since the Mule was a mutant with powers not ever likely to become completely comprehensible to any ordinary man, even a Second Foundationer - rather he deduced them, as the result of intensive training." This is fundementally retconned in Foundation's Edge, in which we see the Second Foundationers "look" into people's minds at will, rather than reading their body expression. Asimov adds to this retcon in Forward the Foundation, in which the Mentalics, the future members of the Second Foundation, portrayed again as literal telepaths rather than adept body-readers, are shown to were born with this ability rather than being trained.
    • Rationalization: While the original Mentalics of the Second Foundation were born telepaths, a few later members such as Preem Palver (the First Speaker) had to be simply trained to deduce people's thoughts through reading body language due to a lack of Mentalics.
      • Discrepancy to Rationalization: As shown in Forward the Foundation, Palver's grandfather Stettin was one of the born Mentalics who began the Second Foundation, and his grandmother was the co-founder, another Mentalic, Wanda Seldon. This means Preem probably should have been one of the Mentalics himself.
      • Discrepancy #2 to Rationalization: Also, in the above quote with regards to the nature Palver's thought-reading, he mentions that no Second Foundationer would ever have powers like the Mule of literal telepathy, so this rationalization is no rationalization at all - he simply would not say this if even a minority of the Second Foundationers were Mentalics - and we know that the majority of them are due to Foundation's Edge.

Between the Robot and Foundation series[]

  • Use of the word "Mile" - According to an unnamed Earthmen to Daneel in Robots and Empire, the word "mile" as a measure of distance has not been used since the prehyperspatial era. However, it is used not only in Foundation, Foundation and Empire, and Second Foundation, but also in Pebble in the Sky, all of which are set thousands of years after Empire. It is also used in Caves of Steel and The Naked Sun.
  • Origin of psychohistory - In The Robots of Dawn, Dr Han Fastolfe appears as the original creator of psychohistory, frequently refers to it as such, and so appears to be the one to create the impractical theoretical science and coin the term. This is backed up by Foundation, which says that Hari "found" psychohistory as a basic theory and heavily improved it into a working mathematics. However, in Prelude to Foundation, Hari goes to the Decennial Mathematical Convention simply to present the basic theoretical possibility, quite literally the "vague set of axioms" that Fastolfe created and that Hari is said to have "found" in Foundation. This would be absurd if Fastolfe and his successors had already developed this basic theory. In addition, Hari appears to have coined the term "psychohistory", even though Fastolfe has already used it in Dawn: "Psychohistory is what I call it," he says to Emperor Cleon.