"Can anybody think of a question science can't answer?"
"Is there a God?" shot back a boy near the window.
"Good," said Campbell, an Anglican who attends church most Sundays. "Can't test it. Can't prove it, can't disprove it. It's not a question for science."
Bryce raised his hand.
"But there is scientific proof that there is a God," he said. "Over in Turkey there's a piece of wood from Noah's ark that came out of a glacier."
Campbell chose his words carefully.
"If I could prove, tomorrow, that that chunk of wood is not from the ark, is not even 500 years old and not even from the right kind of tree - would that damage your religious faith at all?"
Bryce thought for a moment.
"No," he said.
The room was unusually quiet.
"Faith is not based on science," Campbell said. "And science is not based on faith. I don't expect you to 'believe' the scientific explanation of evolution that we're going to talk about over the next few weeks."
"But I do," he added, "expect you to understand it."