“The psychic entropy peculiar to the human condition involves seeing more to do than one can actually accomplish and feeling able to accomplish more than what conditions allow.”

Microserfs (1995)

8 May 1750
Letters to His Son on the Art of Becoming a Man of the World and a Gentleman (1774)

Actually a quotation from a letter of Lord Chesterfield dated May 8, 1750.
Misattributed

Part I : Ambiguity and Freedom
The Ethics of Ambiguity (1947)
Context: Men of today seem to feel more acutely than ever the paradox of their condition. They know themselves to be the supreme end to which all action should be subordinated, but the exigencies of action force them to treat one another as instruments or obstacles, as means. The more widespread their mastery of the world, the more they find themselves crushed by uncontrollable forces.

Part 6 "Beyond System — The Ultimate Source of Jeet Kune Do"
Jeet Kune Do (1997)

quoted in the article The United Nations—How Strong a World Force?, in The Watchtower magazine, September 15, 1974.
Context: You must not expect the United Nations to accomplish miracles. We are made up of sovereign nations. We can only accomplish what our member nations allow us to accomplish.

Don Soderquist “ The Wal-Mart Way: The Inside Story of the Success of the World's Largest Company https://books.google.com/books?id=mIxwVLXdyjQC&lpg=PR9&dq=Don%20Soderquist&pg=PR9#v=onepage&q=Don%20Soderquist&f=false, Thomas Nelson, April 2005, p. 53.
On Creating Teamwork

Statement of purpose, L. Neil Smith's "The Webley Page" http://www.lneilsmith.org/