“Few of us ever test our powers of deduction, except when filling out an income tax form” is a popular tax saying that has been printed on many images. The quotation was included in the book Quotations for Our Time (1977) by Laurence J. Peter (1919-1990). Canadian educator Peter is usually given as the quote’s author, but it’s likely that he collected it from a now-unknown source.
           
 
OCLC WorldCat record
Quotations for Our Time.
Author: Laurence J Peter
Publisher: USA William Morrow & Co. 1977
Edition/Format:   Print book : English
 
13 February 1983, Newsday (Long Island, NY), Tax Book sec., pg. 2, col. 1:
Few of us ever test our powers of deduction, except when filling out a tax form.
—Laurence J. Peter, “The Peter Principle”
     
16 April 1995, New York (NY) Times, “Word for Word-Tax Talk: Render Unto Caesar, Pay the Piper Or Just Get That Check in the Mail” by David E. Rosenbaum, pg. E7, col. 3:
Few of us ever test our powers of deduction, except when filling out an income tax form.
—Laurence J. Peter, author of “The Peter Principle”
 
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“Few of us ever test our powers of deduction, except when filling out an income tax form”—Laurence J. Peter #.. http://tinyurl.com/dhcf67
12:54 AM · Mar 24, 2009·Twitter Web Client
 
Accounting Today 
Comic tax relief
By Robert McKenzie
Published March 23 2018, 7:19am EDT
(...)
“Few of us ever test our powers of deduction, except when filling out an income tax form.’’
— Laurence J. Peter, author
 
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MOSYAN-TAX | TAX CONSULTANT | KONSULTAN PAJAK INDO
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“Few of us ever test our powers of deduction, except when filling out an income tax form.” #mosyantax
6:36 PM · Aug 13, 2019·twittbot.net