"I think one of the things we learned from the physicists and also the theoretical biologists is the idea that when you're dealing with very complex systems you're going to get a large variety of behavior which can be interpreted as hill climbing, but hill climbing with a lot of modifications, hill climbing with big jumps occasionally. This is an elaboration of the idea of the learning model. The learning model story takes off from psychology, but the adaptive processes take off from biology and physics. They have the same story. One thing it does suggest in some sense is that we have to be more modest in what we claim."