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Who really said it

If all you have is a hammer, everything looks like a nail

Not Maslow’s words — a modern paraphrase Abraham Maslow 1908–1970 · American psychologist
Disputed In copyright (the 1966 Maslow passage)

Maslow did write a hammer-and-nail sentence — but not this one. In The Psychology of Science: A Reconnaissance (Harper & Row, 1966) he wrote, “I suppose it is tempting, if the only tool you have is a hammer, to treat everything as if it were a nail.” The snappier “if all you have is a hammer, everything looks like a nail” is a later compression with no documented author, and the underlying law of the instrument was Abraham Kaplan’s, in print before Maslow’s book.

Last verified 24 Aug 2026 · how we verify · spot an error?

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Disputed wording — copy with the correction

“If all you have is a hammer, everything looks like a nail” Abraham Maslow never wrote "if all you have is a hammer, everything looks like a nail." In The Psychology of Science: A Reconnaissance (New York: Harper & Row, 1966), 15–16, he wrote: "I suppose it is tempting, if the only tool you have is a hammer, to treat everything as if it were a nail." The underlying "law of the instrument" was Abraham Kaplan's, reported from a February 1962 speech in the Journal of Medical Education (June 1962). — Quotle.info

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Still under copyright (rights held by the estate of Abraham H. Maslow and the original publisher, Harper & Row of New York, now part of HarperCollins). A short, credited quote is generally fine for talks, teaching, and internal decks; for commercial, published, or large-scale reuse, get permission.

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In context

Evoking the themes of wisdom, doubt and humility. Theme: "If all you have is a hammer, everything looks like a nail". Atmospheric and restrained, cinematic directional light, a muted period-appropriate palette, fine grain and texture. Compose with generous empty space for the quote and a small credit line. No lettering in the image itself.

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Minimalist editorial slide for the quote "If all you have is a hammer, everything looks like a nail". Clean background, a single muted accent color, generous negative space, subtle paper or linen texture, no literal illustration — let the words carry it. Reserve clear space for a serif quote and a small credit line. No lettering in the image itself.

Provenance

What Maslow actually wrote

Work
The Psychology of Science: A Reconnaissance
Author
Abraham H. Maslow
Published
Harper & Row, New York, 1966
Passage
Pages 15–16

… everything else that got into its clutches was treated as if it were an automobile to be washed. I suppose it is tempting, if the only tool you have is a hammer, to treat everything as if it were a nail. Maslow, 1966

Note the hedge — “I suppose it is tempting” — and the verb “treat,” not “looks like.” The popular version drops both.

Book scan
Borrow the 1966 Harper & Row edition at the Internet Archive
Quote Investigator: the full chronology of the hammer-and-nail adage

How a hedged sentence became a proverb

  • February 1962 — the law, without the nail. Abraham Kaplan, a philosophy professor at UCLA, gave a banquet speech at the American Educational Research Association meeting. A report published that June in the Journal of Medical Education carries what Quote Investigator calls the earliest strong match ↗ it has found: “Give a boy a hammer and everything he meets has to be pounded.”
  • 1963 — the nail appears. In Computer Simulation of Personality, the psychologist Silvan Tomkins wrote, “If one has a hammer one tends to look for nails” — the first citation in Quote Investigator’s chronology ↗ to pair the two objects, though the phrasing is still not the modern one.
  • 1966 — Maslow’s version. The Psychology of Science gives the sentence that is closest to what circulates today, and the one Wikiquote lists as sourced ↗: “I suppose it is tempting, if the only tool you have is a hammer, to treat everything as if it were a nail.”
  • 1981–1984 — the compression, and the wrong author. Quote Investigator records “everything looks like a nail” as a 1981 book chapter title and in Warren Buffett’s 1984 Columbia essay, and then an August 1984 letter to InfoWorld ↗ printing the short form under the heading “Twain Said It.”
In copyright

The sentence quoted here is from The Psychology of Science: A Reconnaissance, first published by Harper & Row in New York in 1966 — well inside the term of US copyright, and the Internet Archive scan ↗ is accordingly lending-restricted rather than freely readable. The short popular paraphrase has no identifiable author or first publication, so no rights status can honestly be asserted for that wording; the excerpt above is reproduced in brief for attribution and criticism.

Rights status is our research, not legal advice — and copyright varies by country and edition. For commercial or published use, confirm with the rightsholder. See terms.

Fact-check

Who gets the credit, and who earned it

This adage has been handed to almost everyone. The reference expert Ralph Keyes summed it up in The Quote Verifier: credit “has been given to everyone from Buddha to Bernard Baruch.” Here is what each claim is actually worth.

Nobody documented Paraphrase

“If all you have is a hammer, everything looks like a nail” appears in none of Maslow’s works. Quote Investigator’s chronology ↗ records the compressed shape only from the 1980s — a 1981 Howard J. Ruff chapter title and Warren Buffett’s 1984 “to a man with a hammer, everything looks like a nail” — with no named originator.

Abraham Kaplan, before Maslow Under-credited

The UCLA philosopher named it the law of the instrument. A report of his February 1962 banquet speech, published that June in the Journal of Medical Education, gives the earliest strong match Quote Investigator has found: “Give a boy a hammer and everything he meets has to be pounded.” He restated it in The Conduct of Inquiry (1964), p. 28 ↗. Kaplan’s versions have no nail in them.

Mark Twain No evidence

Twain is the most common recipient and, as Keyes puts it, the credit rests on “no evidence whatsoever” ↗. The earliest Twain credit in Quote Investigator’s record is a reader’s letter to InfoWorld in August 1984 — long after Maslow’s book.

Bernard Baruch, or the Buddha Unsupported

Wiktionary ↗ notes the phrase was labelled “Baruch’s Observation” in The Complete Murphy’s Law (1991). Neither the Baruch nor the Buddha claim is supported by any documented source.

The law is Kaplan’s, the hammer-and-nail pairing was already in print with Silvan Tomkins in 1963, and the wording closest to the modern saying is Maslow’s — but the sentence everyone repeats belongs to none of them. See Quote Investigator’s full trace ↗.

Context

Why Maslow reached for a hammer

Maslow’s hammer is not a line about carpentry. It sits inside a book-length argument that orthodox science had begun to organise itself around its techniques rather than its questions — that researchers were choosing problems to suit the methods they already knew how to run. The sentence arrives as the second half of an image: Maslow describes an elaborate automatic car wash that did a beautiful job of washing automobiles, and treated everything else that fell into its clutches as an automobile to be washed.

That is the joke and the warning together. The tool is not stupid; it is excellent, and its excellence is the problem. Abraham Kaplan had already named the effect the law of the instrument ↗ — “Give a small boy a hammer, and he will find that everything he encounters needs pounding” — but Kaplan’s boy pounds; he never meets a nail. Maslow’s sentence does — Silvan Tomkins had paired the two objects three years earlier — and it is Maslow’s wording that the world remembered.

The tool is not stupid. Its excellence is the problem.

Why the wording drifted

Maslow’s sentence is hedged and conversational — “I suppose it is tempting” — and hedges are the first thing an adage sheds. Quote Investigator’s chronology shows the compressed shape hardening in print through the early 1980s: Howard J. Ruff used “When You Have a Hammer in Your Hand, Everything Looks Like a Nail” as a 1981 chapter title, and Warren Buffett used “to a man with a hammer, everything looks like a nail” in his 1984 Superinvestors of Graham-and-Doddsville essay, crediting it only to “a friend.”

Once a saying loses its author it acquires a better one. By August 1984 a letter to InfoWorld was printing “If the only tool you have is a hammer, everything looks like a nail” and confidently handing it to Mark Twain.

Explore

Filed under

More provenance-checked quotes on the same theme, each with its reuse status.

Wisdom Doubt Humility

Go further

Dig deeper

Trusted places to keep pulling the thread — primary archives, fact-checks, and scholarship. We show how we used each one before you leave.

Quote Investigator: the full chronologyquoteinvestigator.com

The definitive trace, from an 1868 precursor through Kaplan’s 1962 speech, Tomkins in 1963 and Maslow in 1966, to the Mark Twain misattribution of 1984.
Wikiquote: Abraham Maslowen.wikiquote.org

Lists the hammer sentence in its sourced 1960s section, cited to The Psychology of Science (1966), ch. 2, p. 15.
Law of the instrumenten.wikipedia.org

Sets Kaplan’s 1964 formulation (p. 28) beside Maslow’s (pp. 15–16) so the difference in wording is visible at a glance.
The Psychology of Science (1966) at the Internet Archivearchive.org

Scan of the Harper & Row first edition, borrowable through the lending library — the book the sentence actually comes from.
Wiktionary: etymology of the phraseen.wiktionary.org

Traces the modern phrase to Maslow’s 1966 wording and Kaplan’s 1964 law, and records the Twain and Bernard Baruch claims.
Open Library catalogue recordopenlibrary.org

Bibliographic record confirming Harper & Row, New York, 1966 — the publication date that governs the copyright status.

The man whose wording stuck

About Abraham Maslow

Abraham Maslow

1908–1970 · American psychologist, founder of humanistic psychology

Abraham Harold Maslow (1 April 1908 – 8 June 1970) was an American psychologist who taught at Brooklyn College and Brandeis University and founded the humanistic psychology movement. He is best known for Maslow’s hierarchy of needs and the idea of self-actualization. His 1966 book The Psychology of Science: A Reconnaissance argued against a science that puts method before question — and it is where he reached for the hammer that now carries his name.

For writers & researchers

Cite this

How to cite this

Abraham H. Maslow, The Psychology of Science: A Reconnaissance (New York: Harper & Row, 1966), 15–16. The popular short wording is a later paraphrase; the earliest strong match for the adage known to Quote Investigator is a report of Abraham Kaplan’s February 1962 speech in the Journal of Medical Education 37 (June 1962): 637.

This verification page

Quotle.info. “Who really said ‘If all you have is a hammer, everything looks like a nail’?” Last verified 24 Aug 2026. https://quotle.info/who-said/if-all-you-have-is-a-hammer-everything-looks-like-a-nail/

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