“Talents differ; all is well and wisely put;
If I cannot carry forests on my back,
Neither can you crack a nut.”

Back When
Song lyrics, Live Like You Were Dying (2004)

J’ai mis tout mon génie dans ma vie; je n’ai mis que mon talent dans mes œuvres.
Conversation with André Gide in Algiers, quoted in letter by Gide to his mother (30 January 1895); popularized by Gide and often subsequently quoted in Gide’s later work and in "Gide, André (1869-1951)" at Standing Ovations http://www.mr-oscar-wilde.de/about/g/gide.htm; the conversation was again recalled in Gide’s journal of (3 July 1913), quoted in “André Gide’s ‘Hommage à Oscar Wilde’ or ‘The Tale of Judas’”, Victoria Reid (University of Glasgow, UK), Chapter 5 in [Reception of Oscar Wilde in Europe], edited by Stefano Evangelista (8 July 2010) part of a Continuum series The Reception of British and Irish Authors in Europe, ISBN 978-1-84706005-1, pp. 98–99 http://books.google.com/books?id=-oBmdCTSJ5IC&pg=PA98#v=onepage&q=%22I%20put%20all%20my%20genius%22, also footnote 6 (p. 99), quoting 1996 edition of Gide’s journal, pp. 746–47]

"All Because of You"
Lyrics, How to Dismantle an Atomic Bomb (2004)

Interview, The Paris Review (Summer 1956)

Source: Wild: From Lost to Found on the Pacific Crest Trail

Neither natural ability without instruction nor instruction without natural ability can make the perfect artist.
Morris Hicky Morgan translation
Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book I, Chapter I, Sec. 3; translation by Frank Granger

Quoted in "1959 Year In Review: Governor Earl Long Goes Crazy," http://www.upi.com/Audio/Year_in_Review/Events-of-1959/Governor-Earl-Long-Goes-Crazy/12295509433704-5/ UPI.com (1959).