X. But here another question, and that of considerable difficulty, arises, which is, to decide, whether, by this desertion, persons yet unborn may be deprived of their rights. If we maintain that they MAY NOT, the rule already established would be of no avail towards settling the tranquillity of kingdoms, and security of property. For in most things some thing is due to the interests of posterity. But if we affirm that they MAY, it then seems wonderful that silence should prejudice the rights of those, who were unable to speak, before they had any existence, and that the act of OTHERS should operate to their injury. To clear up this point, we must observe that no rights can belong to a person before he has any existence, as, in the language of the schools, there can be no accident without a substance. Wherefore if a Prince, from urgent motives of policy, and for the advantage of his own native dominions, and subjects, should decline to accept an additional sovereignty, or for the same reasons, should relinquish that, which he had already accepted, he would not be charged with injuring his heirs and successors, then unborn, who could have no rights before they had a natural existence. Now as a sovereign may EXPRESSLY declare a change of his will respecting such dominions, so that change may, in certain cases, be implied without such declaration. In consequence of such a change either expressed or implied, before the rights of heirs and successors can be supposed to have any existence, the possession may be considered as entirely abandoned. The case here has been considered according to the LAW OF NATURE: for the civil law, among other fictions, introduced that of the law's personating those, who are not yet in being, and so preventing any occupancy from taking place to their prejudice; a regulation of law established upon no slight grounds in order to preserve estates in families, although every means of PERPETUATING property to individuals, which prevents its transfer from hand to hand, may in some measure be detrimental to the public interest. From whence it is a received opinion, that length of time will give a property in those fees, which were originally conveyed, not by right of succession, but by virtue of primitive investiture. Covarruvias, a lawyer of great judgment, supports this opinion with the strongest arguments in favour of primogeniture, and applies it to estates left in trust. For nothing can prevent the civil law from instituting a right, which, though it cannot be lawfully alienated by the act of one party without consent of the other, yet, to avoid uncertainty in the tenure of present proprietors, may be lost by neglect of claim for a length of time. Still the parties thus deprived may maintain a personal action against those, or their heirs, through whose neglect their right has been forfeited.