When a Distinguished But Elderly Scientist States that Something Is Possible, He Is Almost Certainly Right . . .

Arthur C. Clarke? Isaac Asimov? Apocryphal?

Dear Quote Investigator: The famous science fiction author Arthur C. Clarke believed that proclamations of impossibility were too readily dispensed by blinkered elderly scientists. Would you please help me to find a citation for Clarke’s First Law?

Quote Investigator: In 1962 Arthur C. Clarke published a forward-looking book filled with predictions titled “Profiles of the Future”. The second chapter discussed the failure of imagination that lead to some deeply flawed prognostications. Emphasis added to excerpts by QI: 1

Too great a burden of knowledge can clog the wheels of imagination; I have tried to embody this fact of observation in Clarke’s Law, which may be formulated as follows:

When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.

Clarke further suggested that in the domains of physics, mathematics, and astronautics elderly meant over the age of thirty. In other areas of science the label of elderly may postponed into the forties. Clarke also admitted that there were glorious exceptions to his rather harsh ageism.

Clarke employed Nobel laureate Ernest Rutherford as an example of an older scientist whose vision had dimmed. Rutherford erroneously maintained in 1933 that obtaining useful power from atomic reactions was not possible and that proponents of the idea were “talking moonshine”. A QI article about Rutherford’s remarks is available here. Surprisingly, the brilliant physicist’s extensive knowledge in the subject area hindered his ability to accurately predict the future.

In 1977 prominent science fiction author Isaac Asimov published a column in “The Magazine of Fantasy and Science Fiction” that included an entertaining reaction to Clarke’s Law. Asimov regularly debunked viewpoints that he considered to be pseudo-scientific. Overall, he endorsed Clarke’s Law, but provided an addition to it: 2

I am very selective about the scientific heresies I denounce, for I am guided by what I call Asimov’s Corollary to Clarke’s Law. Here is Asimov’s Corollary:

When, however, the lay public rallies round an idea that is denounced by distinguished but elderly scientists, and supports that idea with great fervor and emotion — the distinguished but elderly scientists are then, after all, probably right.

In conclusion, Arthur C. Clarke deserves credit for the provocative statement he made in 1962, and Isaac Asimov should receive credit for his response in 1977.

Image Notes: Picture of artificial illuminated trees from Free-Photos at Pixabay.

(Great thanks to Kam-Yung Soh who observed in a tweet that the law crafted by Clarke was perfected illustrated by the misguided quotation from Rutherford.)


  1. 1972 (First publication 1962), Profiles of the Future by Arthur C. Clarke, Chapter 2: Hazards of Prophecy: The Failure of Imagination, Quote Page 14, Bantam Books, New York. (Verified with scans)
  2. 1977 February, The Magazine of Fantasy and Science Fiction, Science: Asimov’s Corollary by Isaac Asimov, Start Page 102, Quote Page 104, Mercury Press, Cornwall Connecticut. (Verified with scans)