43. The doctrine may be found in _Leviathan_, Part II., chapter 17. In order 'to erect such a common power as may be able to defend them from the invasion of foreigners and the injuries of one another,' men 'confer all their power and strength upon one man or upon one assembly of men,' ... i.e. 'appoint one man or assembly of men to bear their person.... This is more than consent and concord; it is a real unity of them all in one and the same person, made by covenant of every man with every man, in such a manner as if every man should say to every man, 'I authorise, and give up my right of governing myself to this man or this assembly of men, on condition that thou give up thy right to him and authorise all his actions in like manner.' This done, the multitude so united in one person is called a commonwealth, in Latin _civitas_ ... which (to define it) is one person, of whose acts a great multitude by mutual covenant one with another have made themselves everyone the author, to the end he may use the strength and means of them all, as he shall think expedient, for their peace and common defence. And he that carrieth this person is called sovereign, and said to have sovereign power; and everyone besides, his subject.' 44. In order to understand the form in which the doctrine is stated, we have to bear in mind the sense in which 'persona' is used by the Roman lawyers, as = either a complex of rights, or the subject (or possessor) of those rights, whether a single individual or a corporate body. In this sense of the word, a man's person is separable from his individual existence as a man. 'Unus homo sustinet plures personas.' A magistrate, e.g., would be one thing in respect of what he is in himself, another thing in respect of his 'persona' or complex of rights belonging to him as a magistrate, and so too a monarch. On the same principle, a man, remaining a man as before, might devolve his 'persona,' the complex of his rights, on another. A son, when by the death of his father according to Roman law he was delivered from 'patria potestas' and became in turn head of a family, acquired a 'persona' which he had not before, the 'persona' which had previously belonged to the father. Again, to take a modern instance, the fellows of a college, as a corporation, form one 'persona,' but each of them would bear other 'persons,' if, e.g., they happened to be magistrates, or simply in respect of their rights as citizens. Thus 'one person' above = one sustainer of rights; while in the second passage, ... 'carrieth this person,' it rather = the rights sustained. 45. Hobbes expressly states that the sovereign 'person' may be an _assembly_ of men, but the natural associations of the term, when the sovereign is spoken of as a person, favour the development of a monarchical doctrine of sovereignty.