I have purposely presented the land ethic as a product of social evolution because nothing so important as an ethic is ever ‘written’ … it evolves in… - Aldo Leopold

Only the most uncritical minds are free from doubt.

To build a road is so much simpler than to think of what the country really needs. A roadless marsh is seemingly as worthless to the alphabetical conservationist as an undrained one was to the empire-builders. Solitude, the one natural resource still undowered of alphabets, is so far recognized as valuable only by ornithologists and cranes.
Thus always does history, whether of marsh or market place, end in paradox. The ultimate value in these marshes is wildness, and the crane is wildness incarnate. But all conservation of wildness is self-defeating, for to cherish we must see and fondle, and when enough have seen and fondled, there is no wilderness left to cherish.

Engineers did not discover insulation: they copied it from these old soldiers of the prairie war.