That was the question posed to a group of 7 and 8 year olds. Here's what they had to say:

"It tells you right from wrong, wheither you like it or not"

"When you're good you don't know you have one, but when you're bad it hurts"

"It's like some kind of Chinese food. Foreign to me"

"It's the place in your heart that burns when you do something wrong"

"I don't know. It's too big for me. But I think it has something to do with not kicking girls and little dogs"

"A teacher in your head"

"When you want to do something, it tells you no. Like when I want to beat up my little brother. My conscience has saved him lots of times"