The implications for morality and natural law of Hobbes’s skilful employment of Neoplatonist metaphysics such as Avicenna’s, entailing a sharp division between the human soul and the human body, are spelled out in Chapter 3. This shows that the concept of need, rather than right is central to Hobbes’s natural law and political theory. Judgements concerning needs, including the needs of others, represent a constant source of legitimacy for acting in the state of nature and in the commonwealth. A thorough analysis of the doctrine of necessity in Leviathan, Hobbes’s masterpiece, follows. The superior and absolute sovereignty that Leviathan evaluates and proposes is the true and scientific concept of sovereignty in a commonwealth, by reference to the needs of human nature and also in accordance with divine command. Hobbes exploits his doctrine of metaphysics of necessity to explain that that type of absolute sovereignty is compatible with freedom; after all, each free act of every human being is necessary in the sense of a metaphysics of necessity.