Business and work quotes

Foreword (January 1960)
You Learn by Living (1960)
Context: One's philosophy is not best expressed in words; it is expressed in the choices one makes. In stopping to think through the meaning of what I have learned, there is much that I believe intensely, much I am unsure of. In the long run, we shape our lives and we shape ourselves. The process never ends until we die. And, the choices we make are ultimately our own responsibility.

Often attributed to Eleanor Roosevelt without an original source in her writings, for example in the introduction to It Seems to Me : Selected Letters of Eleanor Roosevelt (2001) by Leonard C. Schlup and Donald W. Whisenhunt, p. 2 http://books.google.com/books?id=UeFWjTMcLZYC&lpg=PP1&pg=PA2#v=onepage&q&f=false. But archivists have not been able to find the quote in any of her writings, see the comment from Ralph Keyes in The Quote Verifier above.
Disputed

Disputed
Variant: No one can make you feel inferior without your permission.
Source: Sometimes claimed to appear in her book This is My Story, but in The Quote Verifier by Ralph Keyes (2006), Keyes writes on p. 97 that "Bartlett's and other sources say her famous quotation can be found in This is My Story, Roosevelt's 1937 autobiography. It can't. Quotographer Rosalie Maggio scoured that book and many others by and about Roosevelt in search of this line, without success. In their own extensive searching, archivists at the Franklin D. Roosevelt Library in Hyde Park, New York, have not been able to find the quotation in This Is My Story or any other writing by the First Lady. A discussion of some of the earliest known attributions of this quote to Roosevelt, which may be a paraphrase from an interview, can be found in this entry from Quote Investigator http://quoteinvestigator.com/2011/03/30/not-inferior/.

Source: You Learn by Living (1960), p. 29–30
Context: You gain strength, courage and confidence by every experience in which you really stop to look fear in the face. You are able to say to yourself, "I have lived through this horror. I can take the next thing that comes along." … You must do the thing you think you cannot do.

Source: The Autobiography of Eleanor Roosevelt

Variant: Success is not the key to happiness. Happiness is the key to success. If you love what you are doing, you will be successful.

The earliest appearance yet located of this statement is in 50 Ways to Lose Ten Pounds (1995) by Joan Horbiak, p. 95, where it is quoted as an anonymous proverb. It seems to have circulated as such for a few years before it began to be attributed to Saint Exupéry around 2007.
Disputed

Variant: great people are those who make others feel that they, too, can become great.

Mark Twain's Notebook, 1887
Letter to Cordelia Welsh Foote (Cincinnati), 2 December 1887. Letter reprinted http://www.twainquotes.com/Success.html in Benjamin De Casseres's When Huck Finn Went Highbrow https://www.worldcat.org/title/when-huck-finn-went-highbrow/oclc/2514292 (1934)

Introduction (1966)
Sometimes misquoted as: Be careful what you pretend to be because you are what you pretend to be.
Mother Night (1961)

No published occurrence of such an attribution has yet been located prior to one in Wilhelm Meisters Wanderjahre — Band 3 http://www.gutenberg.org/cache/epub/2411/pg2411.html by Johann Wolfgang von Goethe
Disputed
Variant: Knowing is not enough; we must apply. Being willing is not enough; we must do.