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Who really said it

In theory there is no difference between theory and practice; in practice there is

Not Yogi Berra — actually Benjamin Brewster Benjamin Brewster Yale College class of 1882 · student essayist
The wording is documented in an 1882 magazine essay; the attribution to Yogi Berra is unsupported. Free to reuse

The line was already in print in The Yale Literary Magazine for February 1882, in an undergraduate essay titled “Theory and Practice” signed Benjamin Brewster — decades before Yogi Berra was born. Quote Investigator ↗ credits Brewster with originating the saying; there is no evidence Berra ever said it.

Last verified 22 Jul 2026 · how we verify · spot an error?

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Disputed credit — copy with the correction

“In theory there is no difference between theory and practice, while in practice there is” Benjamin Brewster, "Theory and Practice," The Yale Literary Magazine, vol. 47, no. 5 (February 1882): 202. Not Yogi Berra. Via Quotle.info

The slide-ready mistake: crediting this to Yogi Berra. Use the credit shown above instead.

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In context

Evoking the world of Benjamin Brewster — essayist, The Yale Literary Magazine. Theme: "In theory there is no difference between theory and practice; in practice there is". 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.

Minimalist

Minimalist editorial slide for the quote "In theory there is no difference between theory and practice; in practice there is". 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

Where the line actually appears

Essay
Theory and Practice
Published in
The Yale Literary Magazine, vol. 47, no. 5, p. 202
Date
February 1882
Author
Benjamin Brewster, Yale class of 1882

I heard no more, for I was lost in self-reproach that I had been the victim of ‘vulgar error.’ But afterwards, a kind of haunting doubt came over me. What does his lucid explanation amount to but this, that in theory there is no difference between theory and practice, while in practice there is? Original 1882 wording

Transcribed by Quote Investigator ↗ from the February 1882 issue. Note the original phrasing — “while in practice there is” — and that Brewster frames it as a wry summary of someone else’s argument, not a maxim.

Quote Investigator: full chronology of the saying

Paper trail

  • February 1882 — earliest strong match located by Quote Investigator ↗: Benjamin Brewster’s essay “Theory and Practice” in The Yale Literary Magazine, p. 202.
  • 1961 — Charles F. Kettering publishes a related remark; QI ↗ calls it a variant, published 1961, not the 1882 saying itself.
  • 1984 — Walter J. Savitch’s programming textbook prints “In theory, there is no difference between theory and practice; but in practice, there is” and credits it only as a remark overheard at a computer science conference — still anonymous, per Quote Investigator ↗.
  • Later — named attributions attach themselves, Yogi Berra among them; Wikiquote ↗ notes the saying circulated anonymously for more than a decade before those names appeared.
Public domain

The Yale Literary Magazine, vol. 47, no. 5, was published in February 1882 — far earlier than 1931, so the issue and Brewster’s essay are in the public domain in the United States. The Online Books Page ↗ lists digitized runs of the magazine as freely available.

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.

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Fact-check

The names it gets pinned on

This is a genuinely old, genuinely anonymous joke that has been handed to four different famous men, none of whom have any documented claim to it.

Yogi Berra Misattributed

Berra was born in 1925 — long after the saying was in print. Wikiquote ↗ lists it in his Misattributed section, noting it circulated anonymously before names began to appear.

Albert Einstein Unsupported

Quote Investigator ↗ points out the expression was already in print before Einstein had reached his third birthday.

Richard P. Feynman Unsupported

Like Berra, Feynman was not yet born when the saying appeared in 1882, and QI ↗ finds no substantive reason to credit him.

Jan L. A. van de Snepscheut Misattributed

The Dutch computer scientist is the name most often attached in tech circles, but his own Wikiquote page ↗ places the line under Misattributed and traces it back to the 1882 Yale text.

Charles F. Kettering Adjacent

Kettering did craft a remark published in 1961, but it runs differently — ending on the point that practice will not let you forget or leave anything out. QI ↗ calls it a variant, published 1961, not the 1882 saying itself.

The credit belongs to Benjamin Brewster, whose essay “Theory and Practice” carried the line in The Yale Literary Magazine for February 1882, per Quote Investigator ↗.

Context

Why this one sticks to Yogi

Yogi Berra was a genuinely funny man who really did say a lot of paradoxical things, and that reputation works like flypaper. Once a line has the right shape — a sentence that folds back on itself and lands on a shrug — the culture files it under Yogi and stops asking questions.

The theory/practice joke has the shape but not the pedigree. It circulated for a century largely unsigned: Quote Investigator ↗ notes that Walter J. Savitch’s 1984 programming textbook printed it as a “remark overheard at a computer science conference,” with no name attached at all. The famous names were bolted on later.

An anonymous joke with a good punchline will eventually find a famous mouth to live in.

The near-misses and the variant that is real

Charles F. Kettering, the General Motors engineer, did craft a related remark that saw print in 1961 — but his version runs differently, ending on the idea that practice will not let you forget or leave anything out. It is a cousin of the 1882 line, not the same line.

Computer scientist Jan L. A. van de Snepscheut is the other name most often attached. His Wikiquote page ↗ puts the quotation squarely in its Misattributed section and points back to the same 1882 Yale text.

Explore

Filed under

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

Wisdom Knowledge Work

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 investigationquoteinvestigator.com

Traces the saying to Benjamin Brewster in the February 1882 Yale Literary Magazine and dismisses the Berra, Einstein and Feynman attributions.
Wikiquote: Yogi Berra (Misattributed)en.wikiquote.org

Files this line under Berra's Misattributed section and notes it circulated anonymously for years before names appeared.
Wikiquote: Benjamin Brewsteren.wikiquote.org

Gives the citation to The Yale Literary Magazine vol. 47, p. 202, and cautions that the essayist was likely not the Standard Oil financier of the same name.
Wikiquote: Jan L. A. van de Snepscheuten.wikiquote.org

Places the quotation in the Misattributed section and cites the 1882 Brewster text plus the 1984 Savitch textbook.
The Yale Literary Magazine archivesonlinebooks.library.upenn.edu

Online Books Page index of free digitized runs of the magazine, covering volumes 1-93 (1836-1928) at HathiTrust.
Yogi Berraen.wikipedia.org

Biography of the catcher (1925-2015), including his own line about things he said that he never said.

The actual originator

Who was Benjamin Brewster?

Benjamin Brewster

Yale College class of 1882 · essayist, The Yale Literary Magazine

Almost nothing is known about him beyond the byline. Quote Investigator identifies the author of the February 1882 essay “Theory and Practice” as a Benjamin Brewster of the Yale class of 1882 — a student writing for his college literary magazine. Wikiquote files the quotation under the Standard Oil financier of the same name while cautioning that the student essayist was almost certainly a different Benjamin Brewster, so the line should not be pinned to the industrialist.

For writers & researchers

Cite this

Primary source

Benjamin Brewster, “Theory and Practice,” The Yale Literary Magazine, vol. 47, no. 5 (February 1882): 202. Earliest strong match located by Quote Investigator, “In Theory There Is No Difference Between Theory and Practice, While In Practice There Is” (14 April 2018).

This verification page

Quotle.info. “Who really said ‘In theory there is no difference between theory and practice; in practice there is’?” Last verified 22 Jul 2026. https://quotle.info/who-said/in-theory-there-is-no-difference-between-theory-and/

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