It is generally conceded that Saul Kripke's groundbreaking monograph Naming and Necessity (1980) has rearranged the landscape of contemporary philosophy. In his book, Kripke sets forth an intriguing line of thought which involves a number of original theses within analytic philosophy and issues into a comprehensive theory of metaphysical essentialism. The present study undertakes a thorough investigation of Naming and Necessity, aiming to attain a perspicuous exposition of the Kripkean programme, to clarify the key notions, and to argue that the realist theory of metaphysical essentialism cannot be retained. The inquiry is thematically concerned with the epistemic and the ontological levels of modality, advancing thereby certain novel ideas regarding the analysis of modal statements which avoid the inconsistencies of realist essentialism and suggest a non-realist reading of Kripkean modality. This book claims the consideration not only of advanced philosophy students and specialists in the field but also of cognitive and social scientists interested in the philosophy of essentialism and modal epistemology.