On Fairy Stories: Eucatastrophe

In my previous video about Tolkien's lecture/essay, "On Fairy Stories" (here: https://www.youtube.com/watch?v=PnMG5HhKK50), I focused on the theme of sub-creation.  Here, I want to discuss another concept, "eucatastrophe," which is a word Tolkien coined to describe it.  Here's the video where I discussed the them of sub-creation in the Silmarillion: https://www.youtube.com/watch?v=HOpbrkRe3Q