Ian and the Limits of Rationality - Issue 107: The Edge

How, he asks, do we complete this pattern? Now a student might say that the next term is 12. When the teacher asks him why, he says, "I looked out the window and saw the number 12 bus go by." One thing you might say is that there's a metarule, a rule about rules, and the metarule is: The only valid rules are ones that don't involve anything specific about the classroom in which the question is asked. So then the student says, fine, the next number in the series is 5. And this time, when you ask him why, he says it's because it's the fifth term in the series.