# Dagger of Detect Evil

A philosopher walked into a magic shop.

"Ugh," said Phil. The philosopher leaned his spear against the hatstand and slumped onto a fluffy cushioned chair.

"Can I get you something to drink? How about Essence of Essence?" said Wiz, the shop owner. She handed Phil a bottle of perfectly invisible liquid. It was clearer than air.

Phil downed the bottle in a single chug.

"I don't know why you do this to yourself. Dungeon crawling. You should be debating the nature of reality. Not scrounging for trinkets in a dark tunnel," said Wiz.

"I would if I could but for some reason people pay more for ancient artifacts of incredible power than for lessons on epistemics," said Phil, "Except for the Court Philosopher. He rakes in the dough. But the rest of us? Not so much."

"Strange," said Wiz.

"Would you like to pay for a lesson on epistemics?" said Phil.

"No thanks," said Wiz.

"Not so strange then," said Phil. Phil took a deep breath. Wiz's shop was passively safe in the sense that nothing would kill you if you didn't poke it first. Which was a step up from Phil's previous week.

"Well," said Wiz.

"Well what?" said Phil.

"Aren't you going to ask me what new inventions I have for you?" said Wiz.

"Oh yeah!" said Phil. He jumped out of the chair. Wiz's inventions always had fascinating metaphysical implications.

The door to the giant room-sized safe/storeroom in the back of Wiz's shop had no keyhole. Wiz just touched it with her hand and the safe opened. The safe was full of boxes and crates and barrels and magical creatures. An imp screeched and banged on the bars of its cage. Various bladed weapons were hung from the ceiling. Wiz removed a haladie dagger and left the storeroom. The door closed behind her.

"This," said Wiz, "is my Dagger of Detect Evil."

Phil was too stunned to say a word.

Wiz smiled the grin of a satisfied engineer.

"It's a what?" said Phil.

Wiz's smile faltered slightly. "It's a Dagger of Detect Evil. You stab an enemy with it and then the dagger will measure whether the enemy was evil. If the enemy was evil then the dagger glows red. Otherwise the Dagger does not glow."

"Let me make sure I heard you correctly," said Phil, "I stab an enemy with it. After I have stabbed an enemy, the dagger will tell me if the enemy was evil."

"Yes," said Wiz.

"That makes no sense!" said Phil.

"Why not?" said Wiz.

"Because evil is not a material phenomenon," said Phil.

"So? I deal with immaterial phenomena all the time," said Wiz, "Just yesterday I visited the astral plane."

"I need to sit down again," said Phil. He sat back in the fluffy chair. This time Phil did not drink. He leaned away from the dagger as if it was poisoned. "I'm not using the word 'material' the way you wizards do, to refer to baseline reality. I'm using 'material' to refer to anything that can be measured or interacted with. The astral plane therefore constitutes a material realm."

"You use words in impractical ways, but I think I understand," said Wiz, "What's your point?"

"That dagger cannot exist," said Phil. "I don't mean it's physically impossible or magically impossible. It's ontologically impossible."

"Nonsense," said Wiz, "The fact that I created this object means that it can exist. Because it does exist. If creating a Dagger of Detect Evil was impossible then I couldn't have created a Dagger of Detect Evil."

Phil held his face in his hands. "You don't understand at all. Evil is a subjective phenomenon. This device represents an objective measurement of a subjective quantity."

"So?" said Wiz.

"Look," said Phil. He looked straight into Wiz's eyes, "What is evil?"

"It's the essence of whatever causes this dagger to glow red," said Wiz.

"Is that definition intersubjectively consistent?" said Phil.

"What?" said Wiz.

"I mean if two people stab the same goblin with a Dagger of Detect Evil will both experiments produce the same result?" said Phil.

"Of course they will," said Wiz, "Otherwise this dagger wouldn't be very useful."

"But people disagree about what evil is," said Phil.

"Then some of those people must be wrong," said Wiz.

"Not necessarily. Perhaps we are talking about two different things. Maybe it's like when we use the word 'material'. Maybe when I use the word 'evil' I'm referring to something immaterial whereas when you use the word 'evil' you're referring to something material. If that's the case then perhaps neither is righter than the other. We are just using words differently," said Phil.

"Does that mean you don't want to buy the dagger?" said Wiz.

"Nonsense," said Phil, "I'll buy two. I would like to prove to the Court Philosopher that I'm right and he's wrong."