“Live simply so that others can/may/might simply live” is a saying that has been printed on many posters. The saying has been attributed to Elizabeth Ann Seton (1774-1821) and Mahatma Gandhi (1869-1948), but there is no evidence that either ever said it.
 
“They are asking themselves how they can live simply so others can simply live” was cited in an October 1974 newspaper article on Iowa religion students. “To live more simply so that others may simply live” was credited in November 1974 to Sister Joan Puls a Franciscan from the Justice and Peace Center in Milwaukee, WI, who was speaking on world hunger. ‘We must learn to live more simply—so others may simply live” was cited in February 1976, also in a church talk on world hunger.
 
 
31 October 1974, Le Mars (IA) Daily Sentinel, “Showing Life” by Phil Ahlers and Terry Roder, pg. 6, cols. 4-5:
In Religion sophomores are studying ways they can spare and share time, talents and material goods for the better of everyone.  They are asking themselves how they can live simply so others can simply live.
 
1 November 1974, The Dubois County Daily Herald Jasper, IN), “Leadership Conference of Women Religious,” pg. 20:
Sister Joan Puls a Franciscan from the Justice and Peace Center in Milwaukee, addressed the Sisters present on “World Hunger,” urging them to look squarely at the problems and discover how the Sisters can effect responsible changes to make the message of the gospel penetrate the world. Sister Joan challenged her audience and their Sisters back home “to live more simply so that others may simply live!”
 
8 November 1974, The Texas Catholic (Dallas, TX), “Women Religious discuss world hunger problem,” pg. 3, col. 1:
ST.-MARY-OF-THE-WOODS, Ind. (NC)—What can women Religious do to effect responsible change in the area of world hunger? That question was one of the main topics discussed by 84 members of the Leadership Conference of Women Religious who met here recently for a regional parley hosted by the Sisters of Providence. “When will we learn to live more simply so that others may simply live?” asked Sister Joan Puls, staff member of the Milwaukee Peace and Justice Office, in a presentation on the problem of world hunger.
 
Google News Archive
24 February 1976, Rome (GA) News-Tribune, “Poverty program Wednesday,” pg. 5, col. 3:
“Our theme is ‘We must learn to live more simply—so others may simply live.’”
(Second Avenue United Methodists.—ed.)
 
Google News Archive
12 April 1976, Sydney (Australia) Morning Herald, “Towards a common life-view” by Reverend Alan Walker, pg. 6, col. 6:
Before such facts, the appeal of Professor Birch is hard to escape: “We must learn to live more simply that others may simply live.”
 
11 February 1977, Daily Republic (Mitchell, SD), “Workshop on lifestyles set at Salem,” pg. 6, col. 1:
Learning how to live more simply that others may simply live is the theme of the Hunger and Christian Lifestyle Workshop to be held in the Salem United Church, Salem, S.D., Feb. 15 from 10 a.m.to 3 p.m.
 
27 March 1977, Lima (OH) News, “Food topic for CWU, pg. B9, col. 1:
Church Women United will meet at 1 p.m. Friday at the YWCA.
 
Mrs. Myra Philpott, home economics agent. Cooperative Extension Service, will have the program on food entitled “Live Simply that Others May Simply Live.”
 
15 April 1978, Richmond (VA) Times-Dispatch, pg. 1, col. 1:
STATE: Residents of a small alternative community in Fluvanna County follow the admonition “live simply so that others may simply live.”
 
20 July 1979, Washington (DC) Star, “Letters to the editor,” pg. A-10, col. 4:
The president’s speech reminded me of St. Elizabeth’s Seton’s plea to “live simply that others may simply live.” Her compassionate vision may be the most realistic advice we could be given.
Albert N. DeMott
Gambrills, Md.
 
Google Books
Perspectives on Applied Christianity:
Essays, in Honor of Thomas Buford Maston
Edited by William M. Tillman
Macon, GA: Mercer University Press
1986
Pg. 88:
The slogan of the simple life-style movement, “live simply so that others may simply live” (adapted from Catholic saint Elizabeth Seton), rings simple but true.
 
Google Books
No Ordinary Moments:
A Peaceful Warrior’s Guide to Daily Life
By Dan Millman
Tiburon, CA: H. J. Kramer Inc.
1992
Pg. 16:
The Simple Life Mahatma Gandhi, nonviolent leader and political activist, advised all of us to “live simply, so that others may simply live.”
   
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Nghia Tran
‏@FiJiNghia
“Live simply so others can simply live.” -Matthew Espinosa @TheMattEspinosa
8:34 PM - 14 Apr 2015
 
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Ashwin Sanghi
‏@ashwinsanghi
Live simply that others might simply live.  ~Elizabeth Ann Seton
12:30 PM - 15 Apr 2015
 
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Mahatma Gandhi
‏@gandhiqts
Live simply that others may simply live.
10:45 PM - 17 Apr 2015