 The crucial premiss of this argument is thus that sameness of truth-conditions entails sameness of ontological commitment. But this is not true. The ontological commitments of a theory (according to Quine, whose notion this is) are those entities that must lie within the domain of quantification of the theory if the theory is to be true; or, the entities the predicates of the theory have to be true of if the theory is to be true. A theory is not ontologically committed, we may say, to whatever has to be in the universe for it to be true, but only to whatever has to be in its universe for it to be true. Thus there is no argument from sameness of truth-conditions to sameness of ontological commitments.