AUDIE CORNISH, HOST:
From NPR News, this is ALL THINGS CONSIDERED. I'm Audie Cornish.
MELISSA BLOCK, HOST:
I'm Melissa Block. And a radio confession here. We had a hole in our program right here. We didn't have a piece just the right length to fill out this segment. It happens occasionally. Well, all summer, NPR science correspondent Joe Palca has been helping us get rid of these little holes with some short stories about holes.
JOE PALCA, BYLINE: Today, we're going to examine the question, what is a hole anyway? What's it made of?
S. MARC COHEN: If you want to get lost in a philosophical thicket, just start asking yourself that question.
PALCA: S. Marc Cohen knows all about philosophical thickets. He's emeritus professor of philosophy at the University of Washington in Seattle. So as a philosopher, he won't get lost in that thicket. He must know what a hole is made of.
COHEN: It's not made of anything, is it?
PALCA: Now, this is a problem, especially for philosophers who think the world is made out of things, a philosophy known as materialism.
COHEN: A materialist would be inclined to say that there aren't really any holes at all. There are no such things as holes. They're merely perforated objects.
PALCA: But since he's not a materialist philosopher, Cohen sees a problem with this perspective.
COHEN: Suppose you ask what a perforated object is. Aren't you inclined to say it's just an object with a hole in it? And there you are. Holes have come back.
PALCA: Okay. We can say holes exist. Well, then the question is, can we get rid of them? So let's say I dig a hole in the ground and fill it back up with dirt.
COHEN: The hole is gone, especially if you fill it with the very same dirt you dug out of it in the first place.
PALCA: Well, that was easy. But what if I fill it up with water? It's not an empty hole, but now it's a water hole and that's not a hole, right?
COHEN: It depends. Maybe it's the pond where there used to be a hole.
PALCA: So you can get rid of a hole by turning it into a pond, but what about the holes in this program that got all this started? How do we get rid of them?
COHEN: The holes in your programming get filled with stories like this one, I suppose.
PALCA: Hooray. I filled the hole in this program. Or did I? Or was it ever really there? Spooky. Joe Palca, NPR News. Transcript provided by NPR, Copyright NPR.