was written and published during a different period from . The earlier work was a product of the late 1950s—a generally optimistic and socially cohesive time when Hayek himself was in his late fifties, at the University of Chicago. , on the other hand, was a product of the 1960s and 1970s, a far more turbulent time, as he became an old man, was somewhat intellectually isolated in Freiburg and Salzburg, and experienced depression. That the later work has a different feel from the former is hardly to be unexpected. The relationship between the two works might be considered to be something like that between Plato’s , a product of his prime, and Plato’s , a product of his old age.
Alan O. Ebenstein