The greatest obstacle to discovery is not ignorance – it is the illusion of knowledge…

Daniel J. Boorstin

Daniel Joseph Boorstin (October 1, 1914 – February 28, 2004) was an American historian, professor, attorney, and writer. He was appointed twelfth Librarian of the United States Congress from 1975 until 1987.

http://en.wikipedia.org/wiki/Daniel_J._Boorstin