Abstract
Kripke distinguishes necessity and priority as two different categories: priority is a notion of epistemology, while necessity is a notion of metaphysics. Based on this fundamental argument, Kripke objects to Descriptivism, which takes certain properties as the criteria of identity across all possible worlds, and he argues for the legitimacy of a posteriori necessary truths. Kripke also criticizes Russell’s methods for dealing with empty descriptions, and he puts forward a modal world to explain the rigidity of proper names. However, the concept of rigid designation faces some challenges, including Kripke admitting to weak essentialism when he rejects transworld identification, and the fact that the truth value of a sentence containing a rigid designator may change.