Certainly for most of human history, including the time when modern economic theory was being developed, human populations and levels of resource use were quite low. Material and energetic limits to growth appeaed so far off that it seemed sensible to ignore them and concentrate on developing a system that efficiently allocated the much scarcer labor, capital, and consumer goods. But since the development of market economies and neoclassical explanations thereof, both human populations and percapita levels of resource use have been increasing exponentially. The success of the market system reduced the relative scarcity of market goods and increased that of nonmarket goods and services provided by the sustaining system. What follows is a very quick assessment of how full the world is and how close we are to resource exhaustion.