 One might take the view that the apparent derivation of a metaphysical conclusion from semantic premises is a sleight of hand, with hidden essentialist premises being smuggled into the argument. If one were to assume that ‘H2O’ is a rigid designator, one might be accused of tacitly assuming metaphysical essentialism. However, one might alternatively take the view that semantics and metaphysics are more intimately related (Bird 2020). For example, one might hold that the semantics itself makes certain metaphysical assumptions, in which case the metaphysics would follow from the semantics, but innocently and for fairly trivial reasons. Note that a thoroughgoing Fregean descriptivism also has metaphysical consequences, since it rules out essentialism. According to the view that the correct semantics implies an essentialist metaphysics, the semantic claim that ‘water’ is a rigid designator is itself metaphysically loaded. But this is not to say that Putnam, Kripke, and other philosophers are smuggling in metaphysical assumptions. Rather, it is to say that competent users of the term tacitly make those assumptions. Putnam’s Twin Earth thought experiments make those assumptions explicit. Note that, as the above discussion has shown, while the thought experiments are normally expressed in the formal mode—we ask whether XYZ would fall within the extension of the term ‘water’ (Earth)—the essentialist conclusion can be reached directly by phrasing the same question in the material mode: we ask whether XYZ would be water.