John O’Donahue gave voice to the connection between beauty and those edges of life—thresholds was the word he loved—where the fullness of reality becomes more stark and more clear. If you go back to the etymology of the word “threshold,” it comes from “threshing,” which is to separate the grain from the husk. So the threshold, in a way, is a place where you move into more critical and challenging and worthy fullness. There are huge thresholds in every life. You know that, for instance, if you are in the middle of your life in a busy evening, fifty things to do, and you get a phone call that somebody you love is suddenly dying, it takes ten seconds to communicate that information. But when you put the phone down, you are already standing in a different world. Suddenly everything that seems so important before is all gone, and now you are thinking of this. So the given world that we think is there and the solid ground we are on is so tentative. And a threshold is a line which separates two territories of spirit, and very often how we cross is the key thing.

Becoming Wise: An Inquiry into the Mystery and Art of Living