Abstract. The purpose of this paper is to propose and consider a new constitutional provision that can contribute to the protection of the vital needs of future generations. The proposal I wish to elaborate can be termed the posterity provision, and it has both substantive and procedural elements. The aim of this constitutional provision is twofold. The first is to encourage state authorities to make more future-oriented deliberations and decisions. The second is to create more public awareness and improve the process of public deliberation about issues affecting near and remote future generations. It is argued that a good case can be made for the proposed reforms compared with alternative substantive constitutional environmental provisions found in existing constitutions and in the literature on legal and political theory. The main reason for this is that the proposed law constitutes a better and more adequate basis for judicial enforcement than the alternatives, which tend to be very vague or unclear. In this connection, I contend that there are both epistemological and moral reasons for introducing constitutional provisions that focus on the protection of critical natural resources essential for meeting the basic physiological needs of future people. It is also argued that the posterity provision can be defended on the basis of central ideas and ideals in recent theory of deliberative democracy.