  Quine therefore rejects Carnap’s picture of science as a two-stage process: the first stage in which we conventionally stipulate constitutive aspects of our scientific language (such as its ontology or logic) based solely upon pragmatic, non-rational factors; the second in which we deploy our language by subjecting non-conventional theories to rational scrutiny. For Quine, this two-stage picture does not describe even idealized scientific inquiry. There is no clear separation between those aspects of theory choice that are solely “pragmatic” and those that are rational.