The rational man finds that his share of the cost of the wastes he discharges into the commons is less than the cost of purifying his wastes before releasing them.

The optimum population is, then, less than the maximum.

Using the commons as a cesspool does not harm the general public under frontier conditions, because there is no public, the same behavior in a metropolis is unbearable.

In a finite world this means that the per capita share of the world's goods must steadily decrease.

In an approximate way, the logic of commons has been understood for a long time, perhaps since the discovery of agriculture or the invention of private property in real estate.

A coldly rationalist individualist can deny that he has any obligation to make sacrifices for the future.