The greatest obstacle to discovery is not ignorance — it is the illusion of knowledge.

Daniel J. Boorstin (1914-2004) American historian, professor, attorney, writer

In Carol Krucoff, “The 6 O’Clock Scholar,” Washington Post (29 Jan 1984)

Full text.In his book, Cleopatra's Nose (1995), Boorstin wrote: "The history of Western science confirms the aphorism that the great menace to progress is not ignorance but the illusion of knowledge."