Which 1939 lecture by J.R.R. Tolkien became an influential essay on fantasy?

J.R.R. Tolkien’s 1939 lecture on fantasy became the influential essay “On Fairy-Stories.”

Tolkien delivered the lecture as the Andrew Lang Lecture at the University of St Andrews in Scotland. He used it to examine what fairy stories are, what they can do, and why adults should not dismiss them as merely childish entertainment.

The essay is especially known for Tolkien’s discussion of fantasy, recovery, escape, and consolation. He also described the “eucatastrophe,” a sudden turn from sorrow toward joy, as a defining feature of the best fairy stories. These ideas became central to later discussions of fantasy literature.

“On Fairy-Stories” was published in expanded form in 1947 and later collected in the volume Tree and Leaf. It is separate from Tolkien’s famous Beowulf lecture, “The Monsters and the Critics,” delivered in 1936. The two works are often mentioned together because both influenced literary scholarship.