Preface http://books.google.com/books?id=aniaAAAAIAAJ&q=%22No+man+who+is+occupied+in+doing+a+very+difficult+thing+and+doing+it+very+well+ever+loses+his+self-respect%22&pg=PR22#v=onepage
1910s, The Doctor's Dilemma (1911)
Variant: No man who is occupied in doing a very difficult thing, and doing it very well, ever loses his self-respect.
George Bernard Shaw: Man (page 4)
George Bernard Shaw was Irish playwright. Explore interesting quotes on man.
"The Living Pictures", The Saturday Review, LXXIX (April 6, 1895), 443, reprinted in Our Theatres in the Nineties (1932). Vol. 1. London: Constable & Co. 79-86
1890s
“You can't make a man a Christian unless you first make him believe he is a sinner.”
Lin Yutang, The Importance of Living (1937), p. 17
Misattributed