Theories, in their proper place.......

     In the spring of 1969, at least, Amos wasn't overtly hostile to the reigning theories in social science.  Unlike Danny, he wasn't dismissive of theory.  Theories for Amos were like mental pockets or briefcases, places to put the ideas you wanted to keep.  Until you could replace a theory with a better theory - a theory that better predicted what actually happened - you didn't chuck a theory out.  Theories ordered knowledge, and allowed for better prediction.  The best working theory in social science just then was that people were rational - or, at the very least, decent intuitive statisticians.  They were good a interpreting new information, and judging probabilities.  They of course made mistakes, but their mistakes were a product of emotions, and the emotions were random, and so could be safely ignored.
     But that day something shifted inside Amos.  He left Danny's seminar in a state of mind unusual for him:  doubt.  After the seminar, he treated theories that he had more or less accepted as sound and plausible as objects of suspicion.

-Michael Lewis, detailing the continuing adventures of Amos Tversky and Daniel Kahneman in The Undoing Project:  A Friendship That Changed Our Minds