This paper is interested in the critical potential of the idea of original common possession of the Earth. On the basis of a comparative analysis of Hugo Grotius and Immanuel Kant, it shows how different the meaning of this idea can be within a theory of property or territory. The first part is devoted to Grotius’s account of why and how the institution of property was progressively introduced. It highlights the importance this account attaches to the intention of the first distributors for a good understanding of property laws, and in particular, for an understanding of their non-application in situations of extreme necessity. The second part takes the opposite path and shows that although Kant rejects the very existence of a right of necessity, the idea that one might be liberated from a law is not completely absent from, and even plays a crucial role in, his account of property. Clarification of this role ultimately leads us back to the idea of original possession in common of the Earth.