Leviathan is a book by Thomas Hobbes, an English philosopher, and this was his famous book which later became the basis for a large part of Western political philosophy. The book centers on his ideas regarding the structure of society as its full name, The Matter, Formed and Power of a Common Wealth Ecclesiastical and Civil, denotes. The basic premise of the book is based on Hobbes argument that it is only through establishment of a commonwealth via social contract that peace and civil unity can be truly achieved. The book is called Leviathan because that in Hebrew (and the Bible) means "sea monster" and in the context of this book, is representative of Hobbes's perfect government, the commonwealth as an enormous human form built out of the bodies of its citizens with the sovereign as its head. Hence, throughout his book, he argues rigorously for the necessity of Leviathan for a peaceful society and averting the threat of civilian conflicts and war.
Leviathan comprises four books: "Of Man," where he sets out the philosophical framework for the entire book and discusses the natural state of man described by "war of every man against every man", to prevent which a social contract and Leviathan are absolutely essential; "Of Common-wealth," in which he outlines the process of establishing the Leviathan, details the rights of both sovereigns and subjects, and postulates legislative and civil governance mechanisms of the his perfect governmental setup; "Of a Christian Common-wealth," which as the name signifies discusses the religious structure of the Leviathan and aligns his philosophy with Christian systems; and "Of the Kingdome of Darkness," where he rejects some of the false religious ideas prevalent at the time and asserts the need for the Leviathanic state to ...