On the nature of Sin by Terry Pratchett, from the book "Carpe Jugulum"
An old woman (who happens to be a witch) and a priest are sitting by the road having a conversation.
(The conversation starts on the classic subject of "how many angels can dance on the head of a pin?")
"Sixteen!"
"You've counted sixteen?" said Oats eventually.
"No, but it is as good an answer as any you'll get. And that's what you holy men discuss is it?"
"Not usually. There is a very interesting debate raging at the moment on the nature of sin, for example."
"And what do they think? Against it, are they?"
"It is not as simple as that. It's not a black and white issue. There are so many shades of gray."
"Nope."
"Pardon?"
There's no grays, only white that's got grubby. I'm surprised you don't know that. And sin, young man, is when you treat people as things. Including yourself. That's what sin is."
"It's a lot more complicated than that--"
"No it ain't. When people say things are a lot more complicated than that, they means they're getting worried that they won't like the truth. People as things, that's where it starts."
"Oh, I'm sure there are worse crimes-"
"But they Starts with thinking about people as things…"
