If Your Only Tool Is a Hammer Then Every Problem Looks Like a Nail

Mark Twain? Abraham Maslow? Abraham Kaplan? Silvan Tomkins? Kenneth Mark Colby? Lee Loevinger? Anonymous?

Dear Quote Investigator: The tools that we are able to apply to problems alter our perceptions of the challenges we face and the solutions that are appropriate. A popular adage illustrates this idea with a compelling analogy. Here are three versions:

1) To a man with a hammer, everything looks like a nail.
2) If your only tool is a hammer then every problem looks like a nail.
3) Give a young boy a hammer, and he will treat everything as a nail.

This saying is often attributed to Mark Twain, but I have been unable to find anything that fits in his writings. Do you know who should receive credit for this modern proverb?

Quote Investigator: Expert Ralph Keyes examined this saying in his reference work “The Quote Verifier”, and he noted that the linkage to Mark Twain was unsupported: 1

Credit for this familiar quotation has been given to everyone from Buddha to Bernard Baruch. Mark Twain is the most common recipient, based on no evidence whatsoever.

A thematic precursor involving a boy was published in a London periodical called “Once a Week” in 1868. The notion of a child wielding a hammer with overeager energy also occurred in later citations: 2

Give a boy a hammer and chisel; show him how to use them; at once he begins to hack the doorposts, to take off the corners of shutter and window frames, until you teach him a better use for them, and how to keep his activity within bounds.

In February 1962 a conference of the American Educational Research Association was held and Abraham Kaplan, a Professor of Philosophy at UCLA, gave a banquet speech. Several months later in June 1962 a report on the gathering was published in the “Journal of Medical Education”. The following excerpt about the speech included the earliest strong match for the adage known to QI. Boldface has been added: 3

The highlight of the 3-day meeting, however, was to be found in Kaplan’s comment on the choice of methods for research. He urged that scientists exercise good judgment in the selection of appropriate methods for their research. Because certain methods happen to be handy, or a given individual has been trained to use a specific method, is no assurance that the method is appropriate for all problems. He cited Kaplan’s Law of the Instrument: “Give a boy a hammer and everything he meets has to be pounded.”

Interestingly, this instance did not contain the word “nail”. Instead, the nail was referenced implicitly via the word “hammer” and the verb “to pound”.

Here are additional selected citations in chronological order.

Continue reading If Your Only Tool Is a Hammer Then Every Problem Looks Like a Nail


  1. 2006, The Quote Verifier by Ralph Keyes, Quote Page 87, St Martin’s Griffin, New York. (Verified on paper)
  2. 1868 April 18, Once a Week, Edited by E. S. Dallas, Number 16, Toys, Start Page 343, Quote Page 344, Column 2, Published by Bradbury, Evans & Company, Fleet Street, London. (Google Books Full View) link
  3. 1962 June, Journal of Medical Education, Volume 37, Trends In Education by Milton J. Horowitz, (Report on the annual meeting of the American Educational Research Association (AERA) held on February 19-21, 1962), Start Page 634, Quote Page 637, Association of American Medical Colleges, Baltimore, Maryland. (Verified on paper)