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?


Absence of evidence may be evidence of absence, depending on what the subject of the question is.

For instance, consider the Bright Pink Screaming Elephant That Lives Outside My House. Because the BPSETLOMH is something that we'd expect to create a great deal of evidence, a lack of evidence is evidence that BPSETLOMH does not exist.

If you believe that were God to exist, he would make his existence known by an abundance of clear, unequivocal evidence, then a lack of evidence is evidence that this type of God does not exist.


Right! He could
- travel around in a ball of fire and flame, bringing food to his followers, and killing those who break his laws or harm his people! And those people could capture the laws, and their amazement, using the best technology of the time: pen and paper! If that doesn't work...
- He could send a human version of Himself around to teach us about Him! And if that doesn't work, because we kill this Teacher, then...
- He could become silent, and subtle, helping those in need quietly, and teaching some of us to help each other.

Jim N

I remember reading that in a hard boiled detective story. It was either in Raymond Chandler's The Big Sleep or it was in a short story in an out-of-print anthology called The Hardboiled Detective.


Could you explain where the phrase "In the clutch" came from? As in, the baseball player hit the winning home run, he really came through in the clutch.

Garson O'Toole

Researcher Stephen Goranson located and shared the following relevant citation on this topic in June 2010. The book scans are in the Google Books database and I have not examined the work on paper. It looks ok.

The Glacialists' Magazine v. 3 pt. 3 Dec. 1895, "On the Occurrence of Scandinavian Boulders in England" by Thomas Sheppard, p. 132 :

Even if no moraine existed, it does not follow that there was no Ice-sheet: it has been remarked by Mr. Dugald Bell that "absence of evidence is not evidence of absence."

Eric M. Jones.

"You can take the boy out of the country but can't take the country out of the boy...." whatever this clever turn of phrase is called. Of course, just because it is catchy doesn't mean it's correct.

It is certainly true that an exhaustive search guarantees that “Absence of evidence IS indeed evidence of absence.” This has been used in math to "solve" for example, the Four Color Problem.

So "A of B isn't B of A" is pretty common in language. As regards "absence..." Here's one (I can see Fred frowning now!)

The ethics of the Hindus--Susil Kumar Maitra - 1925 ( I hope)
" is not the consciousness of the absence of evil but the absence of the consciousness ... "

(I suspect that the British ignored everything the Indians wrote for the two-hundred years of their occupation. Google seems to be on it now....).

ps: Hey Mike Pone: I have a one word proof of the nonexistence of a benevolent God--Neurofibromatosis. By the way...There were no first person writings about Jesus.



'I have a one word proof of the nonexistence of a benevolent God–Neurofibromatosis.'

That would be an example of 'the problem of evil'. ( Enough has been written on this over the millennia to fill libraries. Let's not try to recapitulate it all here.

Garson O'Toole

Here is an entertaining citation on this general theme. It appeared in a book by the mathematician Augustus De Morgan who is famous for De Morgan's laws. The words do not follow the precise template of a chiasmus and that impairs its quotability. But De Morgan is one of the most well-known logicians and that raises its noteworthiness:

Syllabus of a Proposed System of Logic (1860), Page 45. (Google Books full view)
Failure of proof is not proof of the contrary.

Steve Tylock


Couldn't find a better way to answer - you asked for other quotations to trace.

And my quote memory is bad, but the gist is that a prophet has no respect at home, but is widely accepted in foreign lands. I believe it may be biblical, but am not certain.

It has application in business - I'm Steve Tylock, local son in the Rochester NY area, but outside of here, I'm Steve Tylock, Author and LinkedIn expert...

Steven Tylock
The LinkedIn Personal Trainer

Garson O'Toole

Steve Tylock: You are correct that there is a biblical version of the sentiment you expressed. Here are two instances:

John 4:44
King James Bible (Cambridge Ed.) text version from
For Jesus himself testified, that a prophet hath no honour in his own country.

Mark 6:4
King James Bible (Cambridge Ed.) text version from
But Jesus said unto them, A prophet is not without honour, but in his own country, and among his own kin, and in his own house.


This is called in philosophy as "argumentum ad ignoramum" (argument of ignorance), and has been known since the Scholasticists in 12th century.

The concept "abscence of evidence is not evidence of abscence" is very close to Eastern philiosophical concept of "mu".

James A Smith

Dear Mr. Shapiro:

Thanks for looking into this one.

James A. Smith


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.

Sarah K

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!


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?



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?



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.