Freedom in a commons brings ruin to all.

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

Education can counteract the natural tendency to do the wrong thing, but the inexorable succession of generations requires that the basis for this knowledge be constantly refreshed.

Indeed, our particular concept of private property, which deters us from exhausting the positive resources of the earth, favors pollution.

Of course, a positive growth rate might be taken as evidence that a population is below its optimum.