ABSTRACT
The longest of my postwar visits to the United States before 1949 was the one in the spring and early summer of 1946, when I spent in succession two months each at the University of Chicago and Stanford University. It was during that period, when I had more free time than I had had for many years, that I seriously resumed work on the psychological ideas I had begun more than twenty-five years before and which were ultimately published in The Sensory Order.
