Escape, then, is common to many good and bad kinds of reading. By
adding - ism to it, we suggest, I suppose, a confirmed habit of
reading of escaping too often, or for too long, or into the wrong
things, or using escape as a substitute for action where action is
appropriate, and thus neglecting real opportunities and evading real
obligations. If so, we must judge each case on its merits. Escape is
not necessarily joined to escapism. The authors who lead us furthest
into impossible regions--Sidney, Spenser, and Morris--were men active
and stirring in the real world. The Renaissance and our own
nineteenth century, periods prolific in literary fantasy, were periods
of great energy.
C. S. Lewis, An Experiment in Criticism, 1961
