The morality of an act is a function of the state of the system at the time it is performed.

The exquisite sight, sound, and smell of wilderness is many times more powerful if it is earned through physical achievement, if it comes at the end of a long and fatiguing trip for which vigorous good health is necessary. Practically speaking, this means that no one should be able to enter a wilderness by mechanical means.

Numeracy: 1. The art of putting numbers to things, that is, assigning amounts to variables in order that practical decisions may be reach. 2. That aspect of education (beyond mere literacy) which takes account of quantitative aspects of reality.

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

Every measured thing is part of a web of variables more richly interconnected than we know.

Ecological differentiation is the necessary condition for coexistence.

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.