 In the first of these, the Work of Ninety Days, Ockham defended against Pope John XXII the Franciscan claim that the highest form of religious poverty is to live without property or any other right enforceable by a human court. John had argued that no one can justly consume something without owning it. Marsilius and others had answered that we can justly consume things we don’t own if we have the owner’s permission. It was objected that permission confers a right, and permission to consume transfers ownership. Ockham answers by means of a distinction between natural rights and legal  rights.[64]  In the state of innocence ownership would have been contrary to natural law because everyone had a natural right to use any thing (27.80–3, 313), but after the Fall natural law gave (or God gave) to human communities the right to enact human law assigning  property,[65]  i.e., assigning to individuals or groups the right to exclude others from using certain  things.[66]  This law binds morally, since we must respect agreements. Thus the institution of property morally “ties” or impedes the natural right to use things, so that in ordinary circumstances we cannot justly use another’s things. However, the original natural right is not altogether abolished; on some occasions we can still exercise it. For example, if an object is unappropriated, we can use it without asserting property rights over it. In circumstances of extreme need, we can use another’s property to sustain life. Even outside a situation of necessity, we can use another’s property with the owner’s permission, not only to preserve life but for any legitimate purpose. Permission sometimes confers a legal right, but sometimes the person giving permission does not intend to give, nor does the person granted the permission intend to accept, any right enforceable in a human court; in such a case, if the permission is withdrawn, for good reason or not, the person who previously had permission has no legal remedy. Such permission to use property does not confer ownership or any other legal right, or any new right of any kind, but merely “unties” the natural right to use. The natural right is enough to make use, even consumption, just. The Franciscans can therefore justly use and consume things that belong to others without having any legal rights, relying on the natural right to use untied by the owner’s  permission.[67] 