 Building on these ideas, Ockham developed a distinction between three kinds of natural law, according to which some principles of natural law apply everywhere and always, some applied only in the state of innocence, and some apply only “on supposition”, viz. on the supposition of some voluntary act (e.g., an agreement or an act of legislation), unless those concerned agree on something else. Thus “the common possession of all things, the one liberty of all” belonged to the natural law in the state of innocence, but “the acquisition of what is taken from air, land and sea; also, the restitution of a thing or money left for safekeeping” belonged to natural law “on supposition”—supposing Adam’s sin, and supposing that human law has since made a division of property, it is a requirement of natural law to respect others’ property (William of Ockham, Letter: 286–93; commentary in Kilcullen 2001a, Tierney 2014: 103–16). Many things that belong to the law of nations are also natural laws of the third kind.