He who receives an idea from me, receives instruction himself without lessening mine; as he who lights his taper at mine, receives light without darkening me.

Jefferson, Thomas. "Col. Smith, Nov. 13, 1787." The Life and Selected Writings of Thomas Jefferson: Including the Autobiography, The Declaration of Independence & His Public and Private Letters, edited by Adrienne Koch and William Peden. Modern Library, 1998.

Blake, William. "Great things are done when Men & Mountains meet." The Complete Poetry and Prose of William Blake. University of California Press, 2008.

Erasmus. The Adages of Erasmus, edited by William Barker, translated by Margaret Mann Phillips. University of Toronto Press, 2001.