However, as Kripke argued in "Naming and Necessity", a name does not secure its reference via any process of description fitting. Rather, a name determines its reference via a historical-causal link tracing back to the process of naming. And thus, Kripke thinks that a name does not have a sense, or, at least, does not have a sense which is rich enough to play the reference-determining role. Moreover, a name, in Kripke's view, is a rigid designator, which refers to the same object in all possible worlds. Following this line of thought, Kripke suggests that any scientific identity statement such as "Water is H2O" is also a necessary statement, i.e. true in all possible worlds. Kripke thinks that this is a phenomenon that the descriptivist cannot explain.