  Moreover, Duhem does not argue directly for the non-falsifiability thesis. He seems to regard it as an obvious corollary of another thesis, which could be called the non-separability thesis, that the physicist can never submit an isolated hypothesis to experimental test: “To seek to separate each of the hypotheses of theoretical physics from the other assumptions upon which this science rests, in order to subject it in isolation to the control of observation, is to pursue a chimera” (1914, 303; 1954, 199–200).