It is surely a matter of common observation that a man who knows no one thing intimately has no views worth hearing on things in general. The farmer philosophizes in terms of crops, soils, markets, and implements, the mechanic generalizes his experiences of wood and iron, the seaman reaches similar conclusions by his own special road; and if the scholar keeps pace with these it must be by an equally virile productivity.
—Charles Cooley (1864–1929) American Sociologist
Expert: One who limits himself to his chosen mode of ignorance.
—Elbert Hubbard (1856–1915) American Writer, Publisher, Artist, Philosopher
An expert is someone who knows some of the worst mistakes, which can be made, in a very narrow field.
—Niels Bohr (1885–1962) Danish Physicist