It’s so much easier to see and process the world if we divide it into discrete bits. This is non-fiction, that’s fiction. This is a good restaurant, that’s a bad one. This person is succesful, that one isn’t.
These distinctions are almost always wrong.
Not just wrong, but unhelpful, because by ignoring the stuff in between, we isolate ideas (and people) instead of seeing them as part of a continuous whole.
Slopes aren’t necessarily slippery, but they’re far more likely to exist than neat staircases. And then we have to make the very difficult decision of where in the messy middle we’re going to place a marker.