This is a critical edition based on a full study of the manuscript and printing history. It is also an edition to place the English text side by side with Hobbes's later Latin version of it, complete with a set of notes in which the many passages that differ in the Latin are translated into English. So, readers of Leviathan will be able to see every stage of the development of the text at a single glance. Both texts are fully annotated with explanatory notes. The editor's introduction, which takes up the whole of the first volume, aims to give a path-breaking account of the work's context, sources, and textual history.