The Absence of Proof

I’m back to inviting readers to submit quotations whose origins they want me to try to trace, using my book, The Yale Book of Quotations, and my more recent researches.

James A Smith asked:

“‘Absence of proof is not proof of absence.’ Attributed to William Cowper, as a retort to one who claimed God does not exist because we can’t prove his existence.”

I believe any attribution to William Cowper is anachronistic. The Yale Book of Quotations lists a similar saying under the name of Martin Rees, an English astronomer:

“Absence of evidence is not evidence of absence.”


Quoted in Project Cyclops: A Design Study of a System for Detecting Extraterrestrial Intelligent Life, rev. ed., ed. B. M. Oliver and J. Billingham (1973). An earlier version by A. R. Burn appeared in a book review by Burn in The Classical Review, June 1969: “absence of evidence is not identical with evidence of absence.”

Can any readers of this blog supply earlier versions?

Do any readers have any other quotations whose origins they would like me to attempt to trace?

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  1. James A Smith says:

    Dear Mr. Shapiro:

    Thanks for looking into this one.

    James A. Smith

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  2. robinred says:

    But the `absence’ of ultimate proof is the certain proof of the absense. You may want to look up Robyn Ann Goldstein on line. There is an image she patented that communicates just that principle of Mathematics (plural) which goes back to ancient Chinese times.

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  3. Sarah K says:

    Hello- Has this attribution been authoritatively resolved yet? My searches show it to be a somewhat vexed issue. I’d be interested to know if it has because i’m trying to footnote it for my thesis. Any help would be appreciated!

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  4. Pete says:

    I did a quick search in Google books.

    I know the dates as shown in GB are sometimes misleading, but anyway, here’s what I found.

    Journal of the American Medical Association: Volume 141, Part 1
    date given as 1949

    “The lack of evidence of an association between race and blood pressure is not evidence of lack of such an association. ”
    Medical sociology: theory, scope and method by Norman G. Hawkins
    date given as 1958

    “Lack of evidence of association is not the same as evidence of lack of association, nor is evidence of association the same as evidence of connection”
    Poultry digest: Volume 25
    Date given as 1966

    “Over the years, the amount of contact of workers of all types with both agents has been so great, and the degree so intimate, that the lack of evidence of danger can almost be interpreted as evidence of lack of danger”

    any good?

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    • Pete says:

      And another:

      History of Materialism: History of materialism since Kant
      Friedrich Albert Lange
      Date given – 1881

      ” … with the comprehensive thinkers, made Cuvier blind to the great logical difference between the absence of proof and the proof of absence of a phenomenon. ”

      Principles of medical treatment
      George Cheever Shattuck – 1916

      “Depend more on the thermometer and common sense than on the stethoscope and remember that “absence of proof is not proof of absence.”
      The Journal of the American Osteopathic Association: Volume 19
      dated 1919

      “Absence of proof is not proof of absence.” Just because we cannot find a condition does not necessarily prove that no one can find it. It is then time to get some help.

      I’m sure this one counts. You can see the date on the snippet view.
      Hope this link works


      Early pulmonary tuberculosis
      John Bromham Hawes – 1913

      The statement that ” absence of proof is not proof of absence ” applies admirably to this subject.


      Talks on tuberculosis with patients and their friends
      John Bromham Hawes 1931

      Remember that absence of proof is not proof of absence. The fact that this specimen did not show germs of tuberculosis in no way proves that the disease is not present.

      Ohio’s health: Volume 6
      Ohio. Dept. of Health, Ohio. State Board of Health – 1916

      Don’t be in too much of a hurry. 2. Don’t forget to strip the patient to the waist. 3. Do not expect to find marked signs in the lungs in every case. 4. Do not wait for a positive sputum. Absence of proof is not proof of absence. 5. …


      Are these good?

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  5. LeeAnn says:

    Just came across this on page 3 in the book Insect Migration by C.B. Williams, published 1958:

    “Absence of evidence is not evidence of absence.”

    It was in reference to records of insects making return journeys after migration.

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