Prof. Horowitz: It started from idle curiosity. Really. If there is a new epistemology-psychology out there, what would economics built on it look like? All the various economicses are defensible, given their different questions and purposes. The original question here was stricly academic. People who have something `positive' they want to do with economics would hardly be interested in the question; at least, not until the economics suggested had been built, and they could see to what use it might be put.