 In the summer of 1957, Feyerabend accepted an invitation from Michael Scriven to visit the Minnesota Center for the Philosophy of Science in Minneapolis. The Center was, as Feyerabend later said, “one of the foremost institutions in the field” (p. 115). There he met Feigl, Carl Hempel, Ernest Nagel, Hilary Putnam, Adolf Grünbaum, Grover Maxwell, E.L.Hill, Paul Meehl, and others. He returned to the Center in 1958, having accepted another invitation to work there, backed by an NSF grant. He often went back there in subsequent years. 