“If you have to do it, you can do it.”
Mildred Pierce
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James M. Cain 8
Novelist, short story writer, journalist 1892–1977Related quotes

“You have to try, you have to do everything you can.”
Source: Gifted Hands: The Ben Carson Story (1990), p. 76

“Do what you can, with what you have, where you are.”
Ch. IX : Outdoors and Indoors, p. 336; the final statement "quoted by Squire Bill Widener" as well as variants of it, are often misattributed to Roosevelt himself.
Variant: Do what you can, with what you have, where you are.
Attributed to Roosevelt in Conquering an Enemy Called Average (1996) by John L. Mason, Nugget # 8 : The Only Place to Start is Where You Are. <!-- The Military Quotation Book, Revised and Expanded: More than 1,200 of the Best Quotations About War, Leadership, Courage, Victory, and Defeat (2002) by James Charlton -->
Variant: Do what you can, with what you've got, where you are.
Context: There are many kinds of success in life worth having. It is exceedingly interesting and attractive to be a successful business man, or railroad man, or farmer, or a successful lawyer or doctor; or a writer, or a President, or a ranchman, or the colonel of a fighting regiment, or to kill grizzly bears and lions. But for unflagging interest and enjoyment, a household of children, if things go reasonably well, certainly makes all other forms of success and achievement lose their importance by comparison. It may be true that he travels farthest who travels alone; but the goal thus reached is not worth reaching. And as for a life deliberately devoted to pleasure as an end — why, the greatest happiness is the happiness that comes as a by-product of striving to do what must be done, even though sorrow is met in the doing. There is a bit of homely philosophy, quoted by Squire Bill Widener, of Widener's Valley, Virginia, which sums up one's duty in life: "Do what you can, with what you've got, where you are."
“Do all you can with what you have in the time you have in the place you are.”
One Boy's Heroism in the Face of AIDS, National Public Radio, December 1, 2004, 2008-12-27 http://www.npr.org/templates/story/story.php?storyId=4195336,

From an interview published at JamBase.com http://www.JamBase.com

Interview in the documentary-film Cowspiracy by Kip Andersen and Keegan Kuhn (2014).

“Now is no time to think of what you do not have. Think of what you can do with what there is.”
Variant: Now is no time to think of what you do not have.
Think of what you can do with that there is
Source: The Old Man and the Sea (1952)

“How can you do anything until you have seen everything, or as much as you can?”
Source: The Light That Failed

(Handbill advertising Sanger's first clinic, Brooklyn, New York, October 1916) https://sangerpapers.files.wordpress.com/2012/05/sanger_flyer.jpg
published in "Birthright: What's next for Planned Parenthood." Jill Lepore. The New Yorker, Nov. 14 2011 - page 48.