Both [Quine and Feyerabend] want to revise a version of positivism. Quine started with the Vienna Circle, and Feyerabend with the Copenhagen school of quantum mechanics. Both the Circle and the school have been called children of Ernst Mach; if so, the philosophies of Feyerabend and Quine must be his grandchildren.
Ian Hacking, Why Does Language Matter to Philosophy?