Scarcity is any natural or human insufficiency of resources that are objectively or subjectively necessary to realize any given end valued by human beings. To the extent that human life and its ends are construed as materialistic, scarcity is intrinsic to human existence and is a fundamental problem for political science. Scarcity has been a salient issue for modern political theory because of modernity's heightened consciousness of mortality, which has made time and life themselves scarce. Modernity has sought compensations through material abundance for the pain of life's scarcity and the conflicts engendered by that scarcity, though abundance itself has not solved the political problem. Basically, there are two policy options regarding material scarcity: increasing resource supplies and decreasing resource demands. Increasing supplies may be effective in the short run; but decreasing demand may be required in the long run, preferably by revaluing the ends of human life rather than by reducing freedom or opportunities for life itself.The challenge of scarcity to modernity is partly a problem of time. In turn, time is partly a problem of scarcity. Is there sufficient time to make necessary policy adjustments before resources are consumed or, worse yet, before humanity exhausts the capacity of the global ecosystem to support human life? This question can also be turned around. Is the time devoted to resource consumption worthwhile, and does it leave enough time to make life worth living? The latter is more often asked rhetorically than taken seriously; but the facts of the world resource situation may soon push it to the top of the political agenda. The first question presupposes that scarcity is a fact of nature, the second that it is a fact of human existence. What is important, however, is how the nearly infinite potential of human nature interacts with the finite capacity of material nature.