A mind unfree, a mind possessed, dragooned, or indoctrinated, does not learn. It copies. Learning implies discovery. The unfree mind looks at maps but does not travel. It dares not. For at the edge of maps is the jumping-off place, full of dragons and sea serpents. The unfree mind stays home, locks the door, bars the shutters. It is a hero in a crowd, a coward in solitude; it is a slave and a sloth.

Whitney Griswold
Whitney Griswold (1906–1963) American historian, educator [Alfred Whitney Griswold]
“Freedom, Security, and the University Tradition,” speech, Columbia University Bicentennial (1954-06-02)
    (Source)

Reprinted in Griswold, In the University Tradition (1957).